Prescribing Flashcards
Case presentation A 86-year-old man presents to the medical assessment unit complaining of shortness of breath at rest that has worsened over the past month. PMH. Ischaemic heart disease and hypertension. DH. Ramipril 10 mg orally daily, bisoprolol 5 mg orally daily, isosorbide mononitrate 60 mg orally daily, simvastatin 40 mg orally nightly, and aspirin 75 mg orally daily. On examination HR 105/min and regular, BP 110/70 mmHg, JVP elevated at 6 cm, RR 30/min, O2 sat 93% on air. Examination of the chest reveals dullness to percussion both bases and fine inspiratory crackles in both lower zones. Bilateral swollen legs with pitting oedema to knees. Investigations Na+ 141 mmol/L (137–144), K+ 4.2 mmol/L (3.5–4.9), U 7.0 mmol/L (2.5–7.0), Cr 100 µmol/L (60–110). An intravenous infusion of GTN and supplementary oxygen have been initiated. Prescribing request Write a prescription for ONE drug that will help to relieve his fluid overload and breathlessness. (use the hospital ‘once-only medicines’ prescription chart provided)
A. Drug choice Score Feedback/justification B. Dose and route Score Feedback/justification 1 Furosemide 4 This is a powerful loop diuretic and is one of the drugs most likely to achieve a significant diuresis. 40–120 mg IV 4 This dose and route would be likely to achieve a significant diuresis (doses > 50 mg should be given by slow IV infusion) 2 <40 mg IV 2 This dose may produce a suboptimal diuresis 3 >120 mg IV 2 This is an unnecessarily high dose of furosemide that risks causing adverse effects in a diuretic naïve patient 4 20 mg oral 1 This dose is unlikely to be effective 5 40–120 mg oral 2 Any oral route will be less effective than IV 6 >120 mg oral 1 This dose is excessive and the route would be less likely to achieve a significant diuresis 7 Bumetanide 4 Loop diuretic. Not as commonly used in intravenous form as furosemide 1–3 mg IV 4 This dose and route would be likely to achieve a significant diuresis 8 <1 mg IV 2 This dose runs a significant danger of producing a suboptimal diuresis 9 >3 mg IV 2 This is an unnecessarily high dose of bumetanide that risks causing adverse effects in a diuretic naïve patient 10 1-2 mg oral 2 Any oral route will be less effective than IV 11 oral dose outside this range 1 This dose and route are inappropriate 12 Torasemide 2 This is a powerful loop diuretic but is available only via the oral route 5 – 40 mg oral 2 This is the correct dose of torasemide but a parenteral loop diuretic should have been chosen 13 Any thiazide diuretic 1 This is a thiazide diuretic, which will not have sufficient efficacy to achieve a significant diuresis Correct dose and route 1 This is the correct dose but a parenteral loop diuretic should have been chosen 14 Any other diuretic 0 This kind of diuretic will not have sufficient efficacy to achieve a significant diuresis 15 Nitrates 0 The patient is already being given a nitrate 16 Morphine/diamorphine 1 May redistribute fluid but will not improve fluid overload 2.5–10 mg/2.5–5 mg IV 1 Higher doses would be hazardous (0 marks) Marking guide for A and B. Candidates should be given 4 marks for an optimal answer that can’t be improved. They should get 3 marks for an answer that is good but is suboptimal on some grounds (e.g. cost-effectiveness, likely adherence). They should get 2 marks for an answer that is likely to provide benefit but is clearly suboptimal for more than one reason. They should get 1 mark for an answer that has some justification and deserves some credit.
Case presentation A 13-year-old boy is assessed on the paediatric day unit for severe aural pain that has not improved despite 72 hours of treatment with simple analgesia. PMH. None. DH. Paracetamol 1 g orally as required. Allergic to penicillin. On examination T 37.7 oC; HR 100/min; BP 100/68 mmHg. Otoscopy reveals intact red drum, bulging on right side. Prescribing request Write a prescription for ONE drug that will treat his infection. (use the hospital ‘regular medicines’ prescription chart provided)
A. Drug choice Score Feedback/justification B. Dose and Posology Score Feedback/justification 1 Clarithromycin 4 BNF recommended 1st line for penicillin allergy 250 mg 12-hrly orally 4 Recommended dose/posology 2 500mg 12-hrly orally 3 Usually reserved for severe infections 3 500mg 12-hrly iv 1 Parenteral reserved for serious or systemic upset 4 Any other dose/timing/route 0 5 Other macrolide (erythromycin, azithromycin) 4 Acceptable as first line in penicillin allergy in newer versions of BNF Erythromycin 250mg 6-hrly orally Azithromycin 500mg orally daily 4 Recommended dose/posology 6 Erythromycin 500mg 6-hrly orally 3 Usually reserved for severe infections 7 Any IV dose 1 Parenteral reserved for serious or systemic upset 8 Beta lactam antibiotic 0 POTENTIALLY LIFE-THREATENING Any dose of beta-lactam 0 POTENTIALLY LIFE-THREATENING Marking guide for A and B. Candidates should be given 4 marks for an optimal answer that can’t be improved. They should get 3 marks for an answer that is good but is suboptimal on some grounds (e.g. cost-effectiveness, likely adherence). They should get 2 marks for an answer that is likely to provide benefit but is clearly suboptimal for more than one reason. They should get 1 mark for an answer that has some justification and deserves some credit.
Case presentation A 40-year-old man was brought to the Emergency Department after a bystander found him with reduced consciousness. He was found to be hypoglycaemia by the paramedics and has received glucagon 1 mg intramuscularly. On examination Temperature 37.1°C, HR 110/min and regular, BP 121/73 mmHg, O2 sat 99% on 15L oxygen. GCS 6/15. Appears cachectic. Investigations Capillary blood glucose 2.1 mmol/L, ECG sinus rhythm, CXR clear lung fields. Prescribing request Write a prescription for ONE intravenous fluid that would be most appropriate for the patient at this point. (use the hospital fluid prescription chart provided)
A. Drug choice Score Feedback/justification B. Dose and Posology Score Feedback/justification 1 Glucose 20% 4 BNF recommended 1st line fluid 50mL IV stat 4 Recommended dose/posology 2 >50ml IV stat 3 Increased risk of phlebitis 3 <50ml IV stat 2 May not be effective 4 Any of the above with duration longer than 15 minutes – DEDUCT 2 marks 5 Glucose 10% or 50% 3 Likely to be effective, but not first line (recognizing that it used to be 50%, but resulted in risk of phlebitis) 100 mL 10% Glucose IV Stat or 20mL 50% glucose IV stat 3 Equivalent 50mL 20% glucose 6 >100 mL 10% Glucose IV Stat or >20mL 50% glucose IV stat 2 Increased risk of phlebitis 7 <100 mL 10% Glucose IV Stat or <20mL 50% glucose IV stat 1 May not be effective 8 Any of the above with duration longer than 15 minutes – DEDUCT 2 marks (But not negative 9 Glucose 5% or Dextrosaline 0 Unlikely to be very effective Any dose of 5% dextrose or dextrosaline 0 May increase CBG a tiny amount 10 Any other fluid 0 POTENTIALLY LIFE-THREATENING Any other fluid volume 0 POTENTIALLY LIFE-THREATENING Marking guide for A and B. Candidates should be given 4 marks for an optimal answer that can’t be improved. They should get 3 marks for an answer that is good but is suboptimal on some grounds (e.g. cost-effectiveness, likely adherence). They should get 2 marks for an answer that is likely to provide benefit but is clearly suboptimal for more than one reason. They should get 1 mark for an answer that has some justification and deserves some credit.
Case presentation A 68-year-old woman attends her GP after a recent manipulation under anaesthetic for a left Colles’ fracture. PMH. Recent diagnosis of osteoporosis. DH. Calcichew D3 Forte two tablets orally daily. On examination Left forearm in plaster cast. Investigations DEXA scan confirms osteoporosis. Prescribing request Write a prescription for ONE drug will help reduce the risk of further fractures. (use the general practice prescription form provided) Pharmacy Stamp Please don’t stamp over age box Age 0yr 0mths D.o.B. 00/00/0000 Title, Forename, Surname & Address Patient Name Address Line 1 Address Line 2 Town Postcode Number of days’ treatment N.B. Ensure dose is stated 28 Endorsements Drug Name Dose Frequency Signature of Prescriber Signature Date 00/00/0000 For Dispenser No. of Prescns. on form Xxxxx Health Authority Dr Address Town Postcode Tel: 00000 000 000 FP10NC0105
A. Drug choice Score Feedback/justification B. Dose and Posology Score Feedback/justification 1 Alendronic Acid 4 BNF recommended 1st line for post menopausal, secondary prevention of osteoporotic fractures 70mg ORAL once-weekly or 4 Recommended dose 10mg once-daily 2 Recommended dose but not ideal for patient 10mg ORAL once-weeky 1 Too low 70mg ORAL daily 0 Danger of toxicity Other doses 0 (not readily available) 2 Risedronate 4 Now joint 1st line for post menopausal, secondary prevention of osteoporotic fractures ORAL 35mg weekly 4 Recommended dose 5mg ORAL daily 2 Recommended dose but not ideal for patient 5mg ORAL weekly 1 Too low 35mg ORAL daily 0 Danger of toxicity Other doses 0 (not readily available) 3 Strontium ranelate Raloxifene 2 3rd line for post menopausal, secondary prevention of osteoporotic fractures Strontium (ORAL 2g daily), raloxifene (ORAL 60mg daily) 2 Correct doses (any other dose = 0 marks as not readily available) 4 Teriparatide 1 4th line for post menopausal, secondary prevention of osteoporotic fractures 20 micrograms SC daily 1 5 Other bisphosphonates 2 Not recommended for osteoporosis orally Correct dose of other bisphosphonates 2 6 HRT Calcitriol 1 Recommended for corticosteroid induced osteoporosis as 2nd line to bisphosphonates Correct dose of HRT/calcitriol 1 Marking guide for A and B. Candidates should be given 4 marks for an optimal answer that can’t be improved. They should get 3 marks for an answer that is good but is suboptimal on some grounds (e.g. cost-effectiveness, likely adherence). They should get 2 marks for an answer that is likely to provide benefit but is clearly suboptimal for more than one reason. They should get 1 mark for an answer that has some justification and deserves some credit. This
Madeleine Henshaw Age: 82 years Weight: 85 kg, body mass index (BMI) 31 kg/m2 PC Fall causing tibial fracture. HPC Mrs Henshaw went straight to theatre from the emergency department at 09:30 for an open reduction and internal fixation to repair a tibial fracture. This was completed at 11:30. She has now been admitted to the surgical ward. PMH Nil. DH Nil. Intolerances: none known. O/E General Comfortable at rest, pain appears well controlled. Obs HR 65 beats/min, BP 125/85 mmHg, RR 14, oxygen saturation 96% breathing air. CVS Normal examination. Hb 135 g/L 120–160 Plt 225 × 109/L 150–400 Ur 4.9 mmol/L 2.5–8.0 Creat 60 μmol/L 60–110 eGFR >60 mL/min/1.73m2 >60 Task: Prescribe appropriate VTE prophylaxis on the inpatient drug chart.
Prescribe a LMWH, dalteparin. This is prescribed as a once daily dose of 5000 units given subcutaneously. ‘Units’ should be written out in full. The first dose should be given 6 hours after surgery and then once every 24 hours thereafter. As the operation finished at 11:30, it is safe to prescribe the first dose for 18:00 provided there are no ongoing concerns about postoperative haemorrhage. Mrs Henshaw has normal renal function so you do not need to prescribe UFH.
Patient name: Ms Maria Gomez ID number: 100002 Date of birth: 16/08/1910 Age: 104 years Weight: 68 kg Admission date: 07/01/15 Date/time seen: 07/01/15 16:00 History PC Shortness of breath. HPC Ms Gomez has become increasingly short of breath and wheezy over the past 48 hours. She has had no cough or fever, and had otherwise been feeling well prior to this episode.
PMH Chronic obstructive pulmonary disease (COPD), including an infective exacerbation 2 years ago requiring non-invasive ventilation. DH Seretide 250 Accuhaler® (fluticasone 250 micrograms, salmeterol 50 micrograms) 2 puffs twice daily, tiotropium 18 micrograms 1 puff once daily, salbutamol 100 micrograms 2 puffs as needed. Intolerances: none known. SH She is a current smoker who has smoked 5 cigarettes a day for 70 years.
Examination
General She is short of breath at rest. Obs T 36°C, HR 80 beats/min, BP 118/64 mmHg, RR 26 breaths/min, SpO2 95% breathing 35% oxygen via Venturi mask.
RS There is reduced expansion and polyphonic wheeze throughout the chest.
Ix:
CXR: Hyperexpansion, but no consolidation
ABG:
Task Ms Gomez is diagnosed with a non-infective exacerbation of COPD. Prescribe oxygen according to the results of her arterial blood gases.
The target oxygen saturation for patients with chronic lung disease should be set at 88-92%. Ms Gomez achieves oxygen saturations in this range (89%) breathing 28% oxygen with flow rate of 4L/min. The corresponding arterial oxygenation is satisfactory (>8kPa) without significant hypercapnia.
The cause of Ms Gomez’s acute hypoxia is a non-infective exacerbation of her COPD and she should continue on the acute treatment prescribed on her chart. She is prescribed nebulised salbutamol and ipratropium. As she is at risk of carbon dioxide retention with high flow oxygen these should be driven with air.
Patient name: Eoghan O’Connor ID number: 100003 Date of birth: 18/10/1950 Age: 64 years Weight: 73 kg Admission date: 07/01/2015 Date/time seen: 07/01/2015 18:10
History:
PC Severe abdominal pain.
HPC Mr O’Connor has had left lower quadrant pain, fevers and malaise for the past 2 days. His abdominal pain has increased markedly and become more generalised over the past few hours and he now rates it as 10/10 in severity.
PMH Diverticular disease with one previous episode of uncomplicated diverticulitis.
DH Cod liver oil 1 capsule daily. Intolerances: none known.
SH Smokes 1–2 cigarettes per day and drinks about 30 units of alcohol per week. He works as a security guard and is usually fit and active.
Examination General He looks unwell and is clearly distressed by severe pain from his abdomen. Obs T 38.1°C, HR 118 beats/min, BP 116/72 mmHg, RR 28 breaths/min, SpO2 97% breathing oxygen 10 L/min via a facemask.
Systems:Cardiorespiratory examination is normal. On abdominal examination, he has generalised rebound tenderness and guarding consistent with peritonitis. Investigations Baseline investigations are not yet available. Your registrar has seen him and made a provisional diagnosis of acute abdomen due to diverticular perforation. She is arranging for him to be transferred urgently from the emergency department to the operating theatre for a laparotomy, and has asked you to ‘deal with analgesia’. She has asked the nurses to keep Mr O’Connor ‘nil by mouth’. Task Prescribe acute analgesia for immediate administration (all other aspects of his management are being appropriatly addressed by colleagues).
effect. In this situation, you should use a strong opioid, such as morphine. Mr O’Connor is ‘nil by mouth’ due to peritonitis and the need for urgent surgery. The drug should therefore be prescribed for parenteral (non-oral) administration. Other indications for parenteral administration of strong opioids include acute coronary syndromes, painful sickle cell crises, and major trauma.
As IV morphine has a rapid onset of effect, the dose can be titrated (given in small incremental amounts) until the desired level of analgesia is achieved or signs of opioid toxicity emerge. The magnitude of the incremental doses must be decided for the individual patient based on the severity of their pain and their likely sensitivity to the adverse effects of the opioid (which may be increased in advanced age, renal or hepatic impairment, and patients with acute haemodynamic instability). An initial dose of morphine 4 mg. We would assess the effect of this at about 5 minutes: still pain & has no signs of opioid toxicity (i.e. is awake with respiratory rate >8 breaths/minute and no hypotension), it would be appropriate to administer an additional dose, usually half that of the initial dose (2 mg in this case). This may then be repeated at 5-minute intervals until the pain is adequately controlled or signs of opioid toxicity emerge. If he is still in pain after 10 mg has been administered you should seek further advice from a senior colleague. The morphine we administer now will last for at least the next couple of hours, by which time it is to be hoped that he will be under general anaesthesia.
Other Analgesia:
If Mr O’Connor had not already received paracetamol, it would be appropriate to administer this now. Although paracetamol is generally perceived to be a ‘weak’ analgesic, it is an effective drug which works quickly (especially when given intravenously) and by a different mechanism to that of morphine. It may therefore reduce his pain and/or his requirement for morphine.
Other Medications:
Whenever you prescribe a strong opioid by a parenteral route you should also prescribe an anti-emetic that is administered with the first dose of the opioid. E.g.ondansetron 4 mg IV or cyclizine 50 mg IM or by slow IV injection. Metoclopramide should be avoided in patients with suspected gastrointestinal obstruction or perforation as it increases gut motility.
As an operation will happen, laxatives are inappropriate at this stage & should be done post-operatively.
Others: antiobiotics for sepsis (gentamicin if no allergy), VTE prophylaxis.
Patient name: Edna Sullivan I Date of birth: 26/12/1959 Age: 55 years Weight: 78 kg Admission date: 07/01/2015 Date/time seen: 07/01/2015 15:00
History PC Palpitations. HPC Edna Sullivan has been referred to the emergency department by her GP with palpitations for the past 3 days. She has had no chest pain, is not short of breath and has been otherwise feeling well. PMH Hypertension and hypercholesterolaemia. DH Amlodipine 5 mg daily and simvastatin 40 mg daily. Intolerances: none known. SH She is a retired head teacher who lives independently with her husband. She has never smoked. She drinks 8 units of alcohol per week.
Examination: Obs T 36.5oC, HR 162 beats/min, BP 138/82 mmHg, RR 18 breaths/min, SpO2 96% breathing room air. CVS She has an irregularly irregular pulse. Her jugular venous pressure (JVP) is not raised, and she has normal heart sounds. There is no peripheral oedema. RS Normal.
Test Value Normal range Na+ 140 mmol/L 135–145 K+ 4.6 mmol/L 3.5–4.7 Ur 6.1 mmol/L 2.5–8.0 Creat 68 μmol/L 60–110 Adj Ca2+ 2.42 mmol/L 2.20–2.50 Mg2+ 1.0 mmol/L 0.7–1.0 FT4 16 pmol/L 10–23 TSH 3.0 mU/L 0.4–5.0 ECG Rate 160 beats/min, no visible p-waves, irregular rhythm, no other abnormalities
CXR Normal
A diagnosis of atrial fibrillation is made.
Task: Prescribe appropriate initial treatment for the management of Mrs Sullivan’s atrial fibrillation.
Mrs Sullivan is a 55-year-old woman with atrial fibrillation that appears to have been present for at least 72 hours. She has a fast (>100 beats/min) ventricular rate and is experiencing palpitations relating to her arrhythmia. However, there are no features of severely impaired tissue perfusion (e.g. shock, syncope, myocardial ischaemia or pulmonary oedema). Reversible causes of atrial fibrillation, such as infection, hypovolaemia, thyroid disease and electrolyte disturbances, have not been identified by her investigations. In her treatment you therefore need to focus on control of ventricular rate, prevention of thromboembolism and consider whether an attempt should be made to restore sinus rhythm.
Control of Ventricular Rate Control of ventricular rate will relieve symptoms and reduce cardiac work and the risk of complications.
Drug therapies available to control ventricular rate include: beta adrenoceptor blockers (e.g. metoprolol and bisoprolol) non-dihydropyridine calcium channel antagonists (e.g. verapamil and diltiazem) cardiac glycosides (digoxin) amiodarone (can be used for both rate and rhythm control).
Beta adrenoceptor blockers are the first-line choice for control of ventricular rate in stable atrial fibrillation. Beta adrenoceptor blockers commonly used for atrial fibrillation include metoprolol, bisoprolol and carvedilol. Your choice of beta adrenoceptor blocker will be determined by your patient’s comorbidities, local guidelines, availability of medicines and your own experience. A shorter-acting beta adrenoceptor blocker such as metoprolol may be preferable in the first instance, as it will allow more rapid titration of the dose.Target: a ventricular rate of less than 110 beats/min in the first instance.
Non-dihydropyridine calcium channel antagonists are an effective alternative to beta adrenoceptor blockers for acute and chronic rate control. They may be used where beta adrenoceptor blockers are contraindicated, e.g. in patients with asthma. You should not prescribe them with beta adrenoceptor blockers without specialist supervision as, in combination, there is a risk of complete heart block. The cardiac glycoside digoxin can also be used to control the ventricular rate. This effect is often lost during exertion, so digoxin monotherapy should usually be avoided unless the patient is very sedentary. However, digoxin is a useful option for add-on treatment if monotherapy with a beta adrenoceptor blocker or calcium channel blocker is inadequate. In addition, due to its positive inotropic effect, it may be useful in patients with heart failure.
Amiodarone can be used for rate control in patients with atrial fibrillation in special circumstance such as severe left ventricular failure. However, it should be avoided if possible as it can cause severe phlebitis when given intravenously though peripheral veins and in the longer term causes adverse effects on organs such as the thyroid gland and liver. As it can restore sinus rhythm it should be used with caution in patients with atrial fibrillation for >48 hours who are not treated with anticoagulation. Mrs Sullivan has atrial fibrillation uncomplicated by comorbidities. She should therefore be prescribed a beta adrenoceptor blocker.
Prevention of Thromboembolism: Atrial fibrillation carries a significant risk of thromboembolic events, principally stroke. In the short term, we have elected to commence anticoagulation with ‘treatment dose’ low molecular weight heparin (LMWH). In the longer term, oral anticoagulation is likely to be recommended. Drugs indicated for longer term anticoagulation in patients with atrial fibrillation include vitamin K antagonists (e.g. warfarin), novel oral anticoagulants (e.g. dabigatran) and antiplatelet agents (e.g. aspirin). Warfarin, with a target INR of 2–3, is superior (65% risk reduction) to aspirin (20% risk reduction) in reducing the risk of stroke.
Restoration of Sinus Rhythm Restoration of sinus rhythm has the benefits of controlling ventricular rate and reducing the risk of thromboembolic disease. In patients with signs of severely impaired tissue perfusion (e.g. shock, syncope, myocardial ischaemia or pulmonary oedema) immediate electrical cardioversion should be considered. Cardioversion is also an option for patients where onset of atrial fibrillation can clearly be identified as being <48 hours previously. In these patients, pharmacological cardioversion, e.g. using amiodarone, is also an option. Cardioversion should not be attempted at this stage for Mrs Sullivan. As her atrial fibrillation appears to have commenced 3 days ago, there is a risk that cardiac thrombus may have developed and that cardioversion could trigger an embolus and stroke. The decision as to whether sinus rhythm should be restored should therefore be delayed until full anticoagulation is achieved and she can be seen by a specialist in an outpatient clinic. Continuing Usual Treatment You should continue Mrs Sullivan’s regular medications, with careful monitoring of her blood pressure.
We have prescribed metoprolol at the recommended dose for management of arrhythmias in the regular section of the drug chart: 50 mg three times daily. As you are seeing Mrs Sullivan at 15:00 and the next routine dose of metoprolol is due at 16:00, you should prescribe the initial dose in the once only section. Ensure it is clear that this is intended to replace the next scheduled dose, for example by writing ‘OMIT’ against this, as indicated. You should review her response in 2–3 hours as by this time the metoprolol dose should have been fully absorbed. If her rate is not adequately controlled, a further dose may be required. It is good practice to indicate any circumstances under which you would not want a medication given. In this scenario, we have indicated that metoprolol should not be given if the heart rate is less than 50bpm.
Prevention of Thromboembolism We have prescribed dalteparin (an LMWH) to prevent thromboembolism caused by AF.
fibrillation. You will notice that the BNF does not give this as a specific prescribing indication for LMWHs. We have elected to use the dose recommended for the treatment of venous thromboembolic disease. Mrs Sullivan is 78 kg. The dalteparin dose for adults with body weight 69–82 kg is 15,000 units daily (make sure you write ‘units’ out in full). Again we have used the once only section to ensure timely administration before regular dalteparin is commenced. As the next dose of dalteparin is due 3 hours after the initial dose, the regular dose has been omitted as shown. Existing Medications Amlodipine should be prescribed at her usual dose of 5 mg daily in the regular medications section of the chart. As a new beta adrenoceptor blocker has been started it will be important to monitor Mrs Sullivan’s blood pressure to ensure she does not become hypotensive. This has been indicated in the additional instructions box. Her simvastatin should also be prescribed.
Patient: Dragos Hasdeu ID number: 100005 Date of birth: 17/09/1982 Age: 32 years Weight: 85 kg Admission date: 07/01/2015 Date/time seen: 07/01/2015 10:00
History PC Dragos Hasdeu presented to the emergency department with left-sided chest pain and shortness of breath.
HPC The pain has come on gradually over 2 days. He initially thought it was a strained muscle, but now has a sharp left-sided chest pain on breathing or coughing. He normally has unlimited exercise tolerance. However, as the pain has got worse he has felt breathless walking short distances. He feels feverish and shivery and has developed a cough productive of brown sputum. He is able to eat and drink. PMH He is usually fit and well with no previous significant illness. DH None. Intolerances: none known. SH He works on a building site and lives in a flat with two friends. He smokes 15 roll up cigarettes per day and drinks alcohol at the weekends.
Examination General He is in obvious discomfort on breathing. Obs T 38.5°C, HR 102 beats/min, BP 112/86 mmHg, RR 32 breaths/min, SpO2 93% breathing air. RS His left lung base is dull to percussion. On auscultation there are crackles and bronchial breathing at the left lung base.
Test Value Normal range Hb 146 g/L 130–180 WCC 19.4 × 109/L 4.0–11.0 Neut 15.2 × 109/L 1.7–8.0
Plt 178 × 109/L 150–400 Na+ 144 mmol/L 135–145 K+ 4.1 mmol/L 3.5–4.7 Ur 9.6 mmol/L 2.5–8.0 Creat 72 μmol/L 60–110 CRP 284 mg/L <10 CXR Left lower lobe consolidation
Task: A diagnosis of community-acquired pneumonia is made. Prescribe appropriate admission medication.
The most commonly identified pathogen in people with community-acquired pneumonia is Streptococcus pneumoniae (Gram-positive). Other common causative organisms are Haemophilus influenzae (Gram-negative) and atypical organisms including Legionella and Mycoplasma species. Pneumonia can also be caused by Staphylococcus aureus, other Gram-negative organisms and viruses such as influenza A.
The most commonly identified pathogen in people with community-acquired pneumonia is Streptococcus pneumoniae (Gram-positive). Other common causative organisms are Haemophilus influenzae (Gram-negative) and atypical organisms including Legionella and Mycoplasma species. Pneumonia can also be caused by Staphylococcus aureus, other Gram-negative organisms and viruses such as influenza A.
Are There Any Clinical Clues? As Legionella tends to cause more severe forms of pneumonia, illness severity may point to aetiology. The CURB-65 score can be used as a simple severity assessment, with 1 point being allocated for each of new-onset Confusion, Urea >7 mmol/l, Respiratory Rate ≥30 breaths/min, Blood Pressure <90 mmHg systolic or ≤60 mmHg diastolic and age ≥65 years. Pneumonia is considered mild (CURB-65 0–1), moderate (CURB-65 2) or severe (CURB-65 3–5) and risk of death increases with severity. Dragos Hasdeu has moderately severe pneumonia with a CURB-65 score of 2 (raised urea and respiratory rate).
Which Antibiotics? Mild pneumonia is usually treated with a broad-spectrum antibiotic effective against relevant Gram-positive and Gram-negative organisms. A broad-spectrum penicillin (e.g. amoxicillin), a macrolide (e.g. clarithromycin) or a tetracycline (e.g. doxycycline) are all reasonable choices and antibiotics can be given orally if the patient is otherwise well. Moderate and severe pneumonia are treated with a combination of antibiotics effective against Gram-positive, Gram-negative and atypical organisms. A common combination would be a broad-spectrum penicillin (e.g. amoxicillin) with a macrolide (e.g. clarithromycin). Where there are signs of sepsis (e.g. fever, tachycardia and signs of reduced tissue perfusion), antibiotics are usually given initially at high doses via the intravenous route, with a switch to oral antibiotics once the patient is apyrexial, has improved clinically and is able to take treatment orally. In severe pneumonia, co-amoxiclav (amoxicillin and clavulanic acid) may be prescribed instead of amoxicillin as co-amoxiclav is also effective against S. aureus, anaerobes and some organisms resistant to penicillin.
As Dragos Hasdeu has moderately severe pneumonia and no antibiotic allergies, you should prescribe amoxicillin and clarithromycin for him. Local Antibiotic Guidelines Most hospitals and primary care practices have local antibiotic guidelines (see Appendix 1 for an example), which you should always follow when choosing antibiotic treatment. These guidelines aim to balance the benefits of antibiotics with minimising harm (antibiotic resistance, ‘superbug’ infections). For example, severe pneumonia could be treated with benzylpenicillin (highly active against S. pneumoniae) and clarithromycin (active against atypical organisms and some Gram-negative organisms) to reduce the risk of amoxicillin-associated Clostridium difficile infection (see Case 34).
Any Other Treatment? Dragos has hypoxia breathing room air and a raised urea with increased insensible fluid loss due to tachypnoea and pyrexia. He is in pain and has infection and reduced mobility. Supportive care should include oxygen prescription, fluid management, analgesia and prophylaxis against venous thromboembolism (see Case 1). How do I Write the Prescription?
How do I Write the Prescription? Antibiotics: Dragos has moderate severity pneumonia with systemic symptoms and a marked inflammatory response. You should therefore choose antibiotic doses at the upper end of the recommended ranges in the BNF. Intravenous administration would also be reasonable. On the model prescription, amoxicillin has been prescribed intravenously but clarithromycin has been prescribed orally. As intravenous (IV) infusion of macrolides can cause local tenderness and phlebitis and requires a large proximal vein, and their oral bioavailability is high, the IV route tends to be reserved for macrolide use in the most severe infections. Dragos is seen at 10:00, which does not correspond to an administration time for regular prescriptions. You should therefore write the first dose of antibiotics on the once only section of the drug chart and hand this over to a nurse for immediate administration. Subsequent regular doses of antibiotics should be evenly spaced to ensure consistent plasma concentrations for effective eradication of infection. When prescribing antibiotics, you should always indicate the reason for prescription and timing of review. In the model prescription, amoxicillin review has been set for 48 hours, when a switch to oral administration should be considered. Once intravenous administration is no longer required, oral administration is preferred as it is safer, cheaper and allows the patient to leave hospital.
Oxygen: Dragos has hypoxia and hypocapnia with respiratory alkalosis. As adequate oxygenation is essential and he is not at risk of carbon dioxide retention (see Case 2), you should prescribe oxygen with target saturations of 94–98%. A simple face mask would be a reasonable first device for administering oxygen, as controlled oxygen delivery is not required.
Fluids: Dragos has increased insensible fluid loss, tachycardia and a raised urea. He is able to eat and drink so you should encourage oral fluid intake. In the model prescription, 1 L of 0.9% sodium chloride with 20 mmol potassium chloride has prescribed to support oral fluid replacement over the first 8 hours. This should be reviewed. Further fluid therapy should not be prescribed without a review of the patient.
Analgesia: Dragos has pleuritic chest pain, caused by inflammation of the pleura overlying the infected lung. You should consider short-term use of a non-steroidal anti-inflammatory drug (NSAID), which can be very effective for this type of pain. As Dragos is young and has no significant past medical history it is reasonable to prescribe the NSAID with food, but without other prophylaxis against peptic ulceration. In the model prescription, background analgesia with paracetamol (also anti-pyretic) and as required analgesia with codeine phosphate for breakthrough pain have also been prescribed.
Venous Thromboembolism Prophylaxis: Dragos has acute infection, dehydration and reduced mobility, all of which are risk factors for venous thromboembolism. You should therefore prescribe low molecular weight heparin (LMWH) as standard thromboprophylaxis. Dalteparin is the LMWH selected for the model prescription.
Patient name: Helen Yarwood ID number: 100006 Date of birth: 03/12/1969 Age: 45 years Weight: 69 kg Admission date: 07/01/2015 Date/time seen: 07/01/2015 02:00
History PC Helen Yarwood was brought into the emergency department by ambulance with repeated tonic–clonic seizures. You are called to see her because she is having a further seizure, which has lasted 9 minutes so far. HPC Collateral history is available from her son who heard Mrs Yarwood fall out of bed. He found her having a seizure and called the ambulance. She had two further seizures in the ambulance and has not fully recovered consciousness in between. PMH Mrs Yarwood has had epilepsy since her mid-teens. She usually has 1–2 seizures per year, each lasting around 3–5 minutes. DH Carbamazepine 600 mg twice daily. Intolerances: none known. SH Mrs Yarwood lives with her son and daughter and is usually independent. She is a non-smoker and does not drink alcohol. She eats well and is not underweight.
Examination General She is on her left side and is undergoing a tonic–clonic seizure. The trolley has rails which have been raised and padded. She has a nasal airway and intravenous cannula in situ. There are no contusions. Obs T 36.4°C, HR 110 beats/min, BP 138/84 mmHg, SpO2 92% breathing oxygen via non-rebreathe mask at 15 L/minute. Capillary blood glucose 5.9 mmol/L.
Investigations Blood tests sent on admission, including full blood count, renal and hepatic function and electrolytes were all normal apart from: carbamazepine 1mg/L 4-12mg/L
A diagnosis of status epilepticus is made.
Task Prescribe appropriate medication on the drug chart provided.
Status epilepticus is defined as one seizure lasting more than 5 minutes or two or more seizures without a return of consciousness in between. As Mrs Yarwood has had repeated seizures without full recovery of consciousness and her current seizure has lasted 9 minutes, she meets these diagnostic criteria. Status epilepticus is a life-threatening emergency associated with neurological damage and an increased risk of death. Mrs Yarwood therefore needs urgent supportive care and prompt and effective treatment to terminate the seizure.
Urgent Supportive Care: Using the ABCDE approach for the critically ill patient, you can see that Mrs Yarwood has a nasal airway in place, is being nursed on her side and is oxygenating adequately despite her ongoing seizure. She is maintaining an adequate blood pressure and has a cannula in place for intravenous access. Trolley rails and padding have already been implemented to reduce the risk that Mrs Yarwood will injure herself during her seizure.
Emergency Seizure Management The first choice of anti-convulsant for treatment of status epilepticus is a benzodiazepine. Benzodiazepines potentiate the actions of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), which may account for their anti-epileptic activity. You should only prescribe benzodiazepines for seizures lasting longer than 5 minutes, as seizures usually self-terminate within 3 minutes. Mrs Yarwood’s current seizure has now lasted 9 minutes and she has not regained full consciousness between seizures, so benzodiazepine treatment is appropriate. She already has an indwelling intravenous (IV) cannula, so you should prescribe IV lorazepam. Lorazepam is the IV benzodiazepine of choice in status epilepticus, as it has a longer anti-seizure effect and causes less thrombophlebitis than IV diazepam. Where IV access is not possible, you can prescribe buccal midazolam, administered into the oral cavity, or rectal diazepam. After benzodiazepine administration, you should monitor Mrs Yarwood for efficacy (seizure termination, recovery of consciousness) and adverse effects (respiratory depression, hypoxia) of treatment. If seizures persist, you can prescribe a second dose of lorazepam. However, lorazepam should not be given more than twice in a 24-hour period. If seizures continue despite benzodiazepines, IV phenytoin should be given. IV phenobarbitone is an alternative if phenytoin is already being taken or is contraindicated. Patients who continue in status epilepticus despite these measures require sedation and ventilation.
Other Emergency Measures: Metabolic Abnormalities.
If status epilepticus is caused by a metabolic abnormality, such as hypoglycaemia or pyridoxine (vitamin B6) deficiency (malnutrition, isoniazid treatment), you should correct these immediately with IV glucose (20% or 50%) or Pabrinex® (high dose B and C vitamins including pyridoxine and thiamine). In patients at risk of thiamine deficiency (alcohol excess, malnutrition), Pabrinex® should be given before or with intravenous glucose to reduce the risk of glucose precipitating Wernicke’s encephalopathy. Mrs Yarwood does not require intravenous glucose or Pabrinex® as she has normal capillary glucose and no risk factors for pyridoxine or thiamine deficiency.
Further Management: Mrs Yarwood has longstanding epilepsy, usually reasonably well controlled with carbamazepine. However, her blood test currently shows very low plasma carbamazepine concentrations. When she recovers, discussions should include adherence to treatment, any recent changes in prescription or dose and any other new medicines that could potentially interact with carbamazepine. Review by an epilepsy specialist may also be useful. You should also check that Mrs Yarwood does not drive. People with epilepsy must be free of daytime seizures for 1 year or have had asleep-only attacks for 3 years before they can drive a motor vehicle. They cannot drive large goods or passenger vehicles.
How do I Write the Prescription?
Lorazepam Your most urgent task is to terminate her seizure. You should prescribe lorazepam on the once only section of the drug chart for immediate administration. The usual dose is 4 mg given as a slow IV injection over 2 minutes. A maximum of two doses of lorazepam can be given in 24 hours. As long as no other benzodiazepines have been given, e.g. in the ambulance, you should write a second lorazepam dose on the once only section of the drug chart.
Note that in the model prescription we have stated that this second dose of lorazepam is for administration only if the seizure lasts >5 minutes (most self-terminate after 3 minutes). This second advance prescription allows rapid treatment of further seizures if the prescriber is not immediately available. An acceptable alternative would be to prescribe lorazepam in the as required section of the drug chart. However, it must be made clear that Mrs Yarwood should receive a maximum of one further dose today and subsequently should receive no more than two doses in any 24-hour period. Carbamazepine You should prescribe her regular anti-convulsant treatment to start as soon as possible. On the model chart, carbamazepine has been prescribed at the dose that appeared to control her seizures in the past. When she has recovered from status epilepticus, further discussions may result in changes to her treatment. However, prescribing regular anti-convulsant therapy at this stage ensures that it is not forgotten and will help prevent further seizures.
Other Measures:You should prescribe oxygen to maintain saturations at 94–98%. You should carry out a venous thromboembolism assessment and consider whether prophylaxis is needed. Mrs Yarwood has reduced consciousness and is currently trolley-bound so her mobility is reduced. However, she has fallen out of bed, had several tonic–clonic convulsions and is experiencing unusual seizure activity. At this stage it would be reasonable to withhold low molecular weight heparin and impossible to apply anti-embolism stockings. The need for VTE prophylaxis should be reviewed once the seizures have been terminated and further clinical assessment has been performed.
Patient name: Florence Menzes ID number: 100007 Date of birth: 01/02/1987Age: 27 years Weight: 65 kg Admission date: 07/01/2015 Date/time seen: 07/01/2015 23:00
History PC Florence Menzes is seen in the emergency department complaining of a severe headache. HPC A generalised headache has come on over the past 8 hours, gradually increasing in severity. It is now so bad that it is painful for her to move and the light is hurting her eyes. She feels hot and cold and has vomited twice. There is no history of head injury or ear or sinus disease. PMH No previous hospital admissions, no recent illness.
DH Microgynon 30 ® (ethinyloestradiol 30 micrograms, levonorgestrel 150 micrograms). Intolerances: none known. SH Mrs Menzes lives with her husband. She is a non-smoker who drinks 6 units of alcohol per week. Her last foreign travel was 5 years ago. She does not have any contacts that are unwell.
Examination: General She looks unwell and in pain. She is shading her eyes from the light. Obs T 38.2oC, HR 98 beats/min, BP 138/82 mmHg, RR 14 breaths/min, SpO2 100% breathing room air. NS Glasgow Coma Scale 15/15, severe neck stiffness, positive Kernig’s sign. No focal neurological abnormalities. Photophobia but no abnormalities on fundoscopy. Skin No rash.
Investigations:
Test Value Normal range Hb 134 g/L 120–160 WCC 20.4 × 109/L 4.0–11.0 × 109 Neut 18.2 × 109/L 1.7–8.0 × 109 Plt 433 × 109/L 150–400 × 109 Na+ 141 mmol/L 135–145 K+ 4.0 mmol/L 3.5–4.7 Ur 6.0 mmol/L 2.5–8.0 Creat 76 μmol/L 60–110 Gluc (random) 5.6 mmol/L 3.9–7.8 CRP 125 mg/L <10 PT 14 sec 11–16 INR 0.9 0.8–1.1 APTT ratio 1.06 0.85–1.15
cerebrospinal fluid investigation results: Test Result Normal range Appearance Turbid Protein 1.2 g/L 0.2–0.4 Glucose 1.6 mmol/L 2/3 to 1/2 blood glucose Polymorphs 244/mm3 Nil Organisms No organisms seen on Gram-stain
Computed tomography (CT) brain scan – no abnormality, no evidence of raised intracranial pressure. Blood cultures, a blood sample for molecular studies and a throat swab have also been taken.
Task A presumptive diagnosis of bacterial meningitis is made. Prescribe appropriate admission medication.
What Should I Consider When Deciding What to Prescribe? Treatment of Bacterial Meningitis Florence Menzes has bacterial meningitis, which is a life-threatening illness. You need to prescribe intravenous antibiotics and make sure they are administered as soon as the diagnosis is suspected, as urgent treatment saves life and reduces disability.
Which Organism? The most common organisms that cause bacterial meningitis are Neisseria meningitides and Streptococcus pneumoniae. Haemophilus influenzae (b) meningitis has become less common in the UK since the introduction of an effective vaccine. Listeria monocytogenes, Staphylococcus aureus and Gram-negative bacilli are rarer causes of meningitis, which usually affect people who have underlying illness, are immunocompromised or have a cerebrospinal fluid leak.
Which Antibiotics? Florence is 27 years old and has bacterial meningitis caused by an organism which is as yet unidentified. You should therefore prescribe intravenous cefotaxime, which is a broad-spectrum antibiotic that is active against both Gram-negative (N. meningitides, H. influenzae) and Gram-positive (S. pneumoniae) organisms. There is nothing in Florence’s clinical assessment that points to a specific causative organism to help direct therapy. She does not have a non-blanching petechial rash (meningococcus), cerebrospinal fluid leak or ear disease (pneumococcus), travel or prior antibiotic exposure (antibiotic resistance) and is not immunocompromised or over 50 years (listeria). She has no antibiotic allergies. Treatment modifications for different organisms or clinical situations include: Proven meningococcus – cefotaxime might be changed to benzyl penicillin if sensitivities were known Prior antibiotic exposure/travel – consider adding vancomycin to treatment to cover penicillin- and cephalosporin-resistant
Listeria – add amoxicillin to cefotaxime treatment Antibiotic allergies – chloramphenicol can be used in penicillin and cephalosporin-allergic patients Seizure or other features to suggest viral encephalitis – add aciclovir. All such treatment modifications should have input from a specialist in microbiology or infectious diseases. Any Other Treatment? Even with optimal antibiotic treatment, ∼20% of patients with bacterial meningitis die and ∼20% of survivors have neurological complications such as hearing loss or epilepsy. This neurological damage is attributed to the inflammatory host response to infection, which can potentially be suppressed by corticosteroids. A large multicentre clinical trial found that administration of the corticosteroid dexamethasone to patients with suspected bacterial meningitis (starting with or just before the first dose of antibiotics) reduced death and disability. The benefit appeared most marked in patients with meningitis caused by S. pneumoniae. Most specialists would therefore now recommend giving dexamethasone with the first dose of an appropriate antibiotic for suspected bacterial meningitis. Dexamethasone should be continued for confirmed pneumococcal meningitis and stopped if bacterial infection is ruled out. It is less clear whether dexamethasone is beneficial in non-pneumococcal bacterial meningitis, so you should ask for advice from your local specialist (infection or neurology).
Relief of Symptoms You need to prescribe analgesia to relieve Florence’s headache. One option would be regular paracetamol for background analgesia with a moderate (codeine) and/or strong (morphine) opioid analgesic. You should be aware of the side effects of opioid analgesia such as sedation and vomiting which could be confused with clinical deterioration due to worsening bacterial meningitis. Florence has been vomiting. You should prescribe an anti-emetic, such as metoclopramide, cyclizine or prochlorperazine. This may enable her to take oral fluids and analgesia, which will make her condition easier to manage.
Fluids: Her blood pressure, electrolytes and renal function are all normal, indicating that she is not significantly fluid depleted. Her fluid maintenance requirements are likely to be increased by pyrexia, which increases insensible losses. If possible she should be encouraged to take fluids orally. If this is prevented by vomiting, intravenous fluids should be prescribed.
Prophylaxis against Venous Thromboembolism: Florence is at risk of venous thromboembolism (VTE) due to reduced mobility, sepsis and oral contraceptive use. However, she has just had a lumbar puncture, with some associated risk of bleeding. You should therefore prescribe low molecular weight heparin, but delay dosing for at least 4 hours after the lumbar puncture was performed. It is important to be sure that coagulation is normal before prescribing VTE prophylaxis as sepsis can lead to coagulopathy.
How do I Write the Prescription?
Cefotaxime: You must make sure that Florence receives her antibiotics immediately. One way of doing this is to write the first dose as a once only prescription to be given now (and hand this over to the responsible nurse to ensure immediate administration), with subsequent doses in the regular prescription section. In the model chart this has also been done for dexamethasone and paracetamol. As bacterial meningitis is a severe infection, you should prescribe high-dose cefotaxime (2 g 6-hourly, as opposed to the usual dose of 1 g 6-hourly). It is important that the plasma concentrations of cefotaxime are consistently high to eradicate the infection. To achieve this, you should space cefotaxime doses evenly over 24 hours. This is shown on the model prescription, with doses at 6am, midday, 6pm and midnight. When writing up antibiotic treatment you should specify the indication and duration of treatment as shown. Cefotaxime should usually be given intravenously for at least 10 days for bacterial meningitis, although treatment may be modified once the diagnosis is clarified.
Dexamethasone: On the model prescription dexamethasone has been prescribed as recommended for bacterial meningitis in the British National Formulary. The dose and duration of treatment are those that were beneficial when tested in a multicentre clinical trial.
Analgesia and Anti-Emetics When writing up analgesia and anti-emetics for Florence, you should consider route of administration. Oral administration is convenient and acceptable to patients and generally safer than intravenous (risk of infection, toxicity from drug bolus) or intramuscular (risk of haematoma, unpredictable absorption) administration. However, oral administration may not be appropriate for Florence who has been vomiting. On the model drug chart this has been addressed by an intravenous prescription of regular paracetamol with a review date, when a change to oral and/or less frequent administration should be considered. The as required prescription of the anti-emetic cyclizine has been prescribed for either oral or intravenous administration at the discretion of the administering nursing staff. This is possible as cyclizine dose and frequency of administration is the same by either route.
Low Molecular Weight Heparin: You should prescribe this to start at least 4 hours after the lumbar puncture. On the model prescription an interval of 12 hours has been ensured.
Oral Contraception: While Florence is unwell with bacterial meningitis, maintenance of oral contraception is not a priority and may add to the risk of VTE. On recovery you should discuss issues around restarting oral contraception including timing and initial alternative precautions.
