Prescribing Flashcards
What dose of statin is used for primary and secondary prevention of cardiovascular disease?
Primary: 20mg atorvastatin
Secondary: 80mg atorvastatin
NOTE: rosuvastatin is a potent statin that is more likely to cause statin-induced myopathy
Describe management of C. difficile infection?
1st episode: Vancomycin PO
Relapse within 12w: Fidaxomycin
Severe infection: Vancomycin PO + IV Metronidazole
What dose of omeprazole is used for peptic ulcers, gastro-oesophageal reflux and the prevention of ulcers?
Omeprazole 20 mg OD (usually for 4-8w)
What is the first-line treatment option for cellulitis?
Oral flucloxacillin 250-500 mg QDS
2nd line: oral clarithromycin 250 mg BD for 7–14 days (up to 500 mg BD for severe infections)
Which dose of cyclizine is used in nauseated patients?
Cyclizine 50 mg 8-hourly IM/IV/oral
WARNING: can cause fluid retention so avoid in heart failure
What is the maximum dose of PRN paracetamol?
Paracetamol 1g every 6h (max 4 g/day)
Which PRN pain relief should be given for patients with mild pain?
Codeine 30 mg up to 6-hourly
Which regular medication should be prescribed for patients with severe pain?
Co-codamol 30/500, 2 tablets every 6h
WARNING: pay attention to how much paracetamol a patient is taking if they are taking PRN co-codamol + regular paracetamol
Which PRN medication should be prescribed for severe pain?
Morphine sulphate PO 10mg/ 5ml up to 6-hourly
Which medications are used first-line in neuropathic pain?
Amitriptyline 10 mg oral nightly
Pregabalin 75 mg oral 12-hourly
What dose of ibuprofen should be used for pain?
Ibuprofen 400 mg 8-hourly
What is the dividing factor for dosing when switching patients from oral codeine to oral morphine?
Divide by 10
Same with oral tramadol to oral morphine
For patients with advanced and progressive disease who are in pain, what should be prescribed provided there are no comorbidities?
20-30mg modified-release oral morphine (or immediate-release based on patient preference) - e.g. 15mg BD
With 5mg immediate-release oral morphine for breakthrough pain
If a patient on 30 mg morphine sulphate BD is switched onto a syringe driver, what dose of subcutaneous morphine should be given?
30 mg in 24h
NOTE: if changing to SC morphine from PO, dose should be divided by 2
NOTE: if changing to SC diamorphine, it should be divided by 3
What should be coprescribed in patients who develop pneumonia after influenza?
Flucloxacillin (cover S. aureus)
What does 1% mean with regards to weight/volume calculations? (e.g. 1% lidocaine)
1g in 100mL (i.e. 10mg in 1mL)
What does PReSCRIBER stand for?
Patient details (name, DOB + hospital number) Reaction (e.g. allergy) Sign the front of the chart Contraindications to each drug Route IV fluids necessary? Blood clotting prophylaxis necessary? Anti-Emetic necessary? Pain Relief necessary?
What is the starting dose of ramipril and lisinopril in heart failure?
Ramipril: 1.25 mg OD
Lisinopril/Enalapril: 2.5 mg OD
When should ACE inhibitors be taken?
In the evening/ night as it can cause postural hypotension
What dose of verapamil is used for rate control in atrial fibrillation?
40 mg 8-hourly
What is the usual daily starting dose of levothyroxine in hypothyroidism?
50-100 mcg
NOTE: in elderly patients + those with comorbidities, a starting dose of 25 mcg OD may be used
What is the usual dose of amlodipine used for hypertension?
5mg OD
Maximum of 10mg OD
NOTE: it does not need to be taken at night
Which medications are usually taken at night?
Statins
Amitryptiline
NOTE: atorvastatin can be taken at any time of the day
What is an appropriate starting regime of analgesia for palliative patients?
20-30mg per day of modified-release morphine + 5 mg morphine for breakthrough pain
Outline the rules for converting doses of opioids.
Oral codeine –> oral morphine = divide by 10
Oral tramadol –> oral morphine = divide by 10
Oral morphine –> oral oxycodone = divide by 1.5-2
Oral morphine –> SC morphine = divide by 2
Oral morphine –> SC diamorphine = divide by 3
Which opioids are preferred in CKD?
Buprenorphine and alfentanil
NOTE: same drug should be used for maintenance + break-through pain (e.g. fentanyl 50 mcg/actuation nasal spray in each nostril repeated after 10 mins if required)
Which analgesic should you prescribe to a patient with renal colic?
IM diclofenac 75 mg
How big should the breakthrough dose of morphine be?
1/6 of the daily dose
What is the starting dose of methotrexate for rheumatoid arthritis?
7.5mg weekly
5mg folic acid should be co-prescribed, to be taken >24h after the methotrexate dose
NOTE: methotrexate is available in 2.5mg pills
List 8 p450 inducers.
Sulphonylureas
Carbamezapine
Rifampicin
Alcohol (chronic)
Phenytoin
Griseofulvin
Phenobarbitone
St. John’s wort
Describe the effect of cigarette smoking on the cytochrome P450 enzyme system
Enzyme inducer
Decreases drug concentration
List some p450 inhibitors.
SICKFACES.COM
Sodium valproate
Allopurinol
Ritonavir
Cimetidine
Alcohol (acute intake)
Sulfonamides
Metronidazole
Verapamil
Isoniazid
Amiodarone
Anti-fungals: Ketoconazole, Fluconazole
Ciprofloxacin
Chloramphenicol
Omeprazole
Macrolides: Clarithromycin, Erythromycin
What are some adverse drug reactions associated with gentamicin and vancomycin?
Nephrotoxicity
Ototoxicity
Which antibiotics are particularly notorious for causing C. difficile colitis?
Cephalosporins (Cefotaxime, Ceftriaxone
Clindamycin
Ciprofloxacin
List 4 adverse effects of ACE inhibitors.
Hypotension
Electrolyte abnormalities (hyperkalaemia)
AKI
Dry cough
List 4 adverse effects of beta-blockers.
Hypotension
Bradycardia
Wheeze in asthmatics
Worsens acute heart failure (drops CO)
What mechanism can cause adverse effects in dihydropyridine CCBs?
Vasodilatory effect lowers BP, causes Reflex tachycardia (esp. Nifedipine)
Where do dihydropyridine and non-dihydropyridine CCBs mainly exert their effects?
Dihydropyridine: vascular smooth muscle (Nifedipine + Amlodipine)
Non-dihydropyridines: Heart (Verapamil > Diltiazem)
List 2 adverse effects of heparins.
Haemorrhage (esp. if renal failure or <50kg)
Heparin-induced thrombocytopaenia
List 3 adverse effects of aspirin.
Haemorrhage
Peptic ulcers
Tinnitus
List 6 adverse effects of digoxin.
N+V
Diarrhoea
Blurred vision
Confusion
Drowsiness
Xanthopsia (yellow-green visual perception)
List 4 adverse effects of amiodarone.
Interstitial lung disease
Thyroid disease
Grey skin
Corneal deposits
List the early, intermediate and late adverse effects of lithium.
Early: tremor
Intermediate: tiredness
Late: arrhythmias, seizures, coma, renal failure, diabetes insipidus
List 4 adverse effects of statins.
Myalgia
Abdominal pain
Increased ALT/AST
Rhabdomyolysis
List 4 common drugs that have a narrow therapeutic index.
Warfarin
Digoxin
Phenytoin
Theophylline
Which 4 commonly used medications should be stopped before surgery?
Antiplatelets
Anticoagulants
COCP
Lithium (omit day before surgery)
What is the usual daily dose of alendronic acid?
10 mg
NOTE: 70 mg can be given WEEKLY in patients with post-menopausal osteoporosis
List 3 commonly used classes of medication that cause indigestion.
NSAIDs
Steroids
Bisphosphonates
What is the usual treatment dose of enoxaparin?
1.5 mg/kg
NOTE: 40 mg is the prophylactic dose
Which medications can reduce renal excretion of lithium?
ACE inhibitors
Diuretics (particularly thiazides)
NSAIDs
NOTE: if diuretics must be used in a patient on lithium, use loop diuretics
What is the target range for TSH in a patient with hyperthyroidism?
0.5-5.0 microU/L
When might you expect fluid input to be greater than fluid output in a patient?
Correction of dehydration
Renal failure
What are the daily maintenance requirements of fluid and potassium when NBM?
Fluid: 3 L (i.e. 1L per 8h)
K+: 40-60 mmol
So, 1L 0.9% saline with 20 mmol KCl over 8h
Which type of fluid should be used for maintenance in adults who are NBM?
Provided biochemistry is normal, they should have:
1L of 0.9% saline
2L 5% dextrose
Every 24h with 40-60 mmol KCl per day
What is the first-line diabetic medication in patients with CKD?
Gliclazide
Metformin cannot be used if GFR < 30 ml/min
What is the normal starting dose of amitryptyline?
10 mg
Which antibiotic commonly interacts with statins and how should you deal with it?
Clarithromycin
It is a CYP3A4 inhibitor and it increases the toxicity of statins. So, statins should be stopped during the course of clarithromycin.
Which medication can give immediate relief for patients with dyspepsia?
Magnesium carbonate 10 mL TDS
What is a major contraindication for using lactulose?
Bloating
What are some major contraindications for using Senna?
Colitis and cramps
What is the main difference between the side-effects of codeine and tramadol?
Codeine: constipation
Tramadol: agitation/ hallucinations
NOTE: both cause typical opioid SEs (respiratory depression, reduced consciousness, pinpoint pupils)
What dose of codeine is typically used for the management of pain?
30mg 6-hourly
NOTE: max daily dose is 240mg
What is the best way of measuring the therapeutic effect of an aminophyline infusion?
Oxygen saturations will improve
What is the best way of measuring tacrolimus levels in transplant patients?
Trough level before the morning or evening dose (aim for 6-10 ng/mL)
What is the target pre-dose trough concentration for vancomycin?
10-15 mg/L
List 9 common side-effects of calcium channel blockers.
Abdominal pain
Dizziness
Drowsiness
Flushing
Headache
N+V
Palpitations
Peripheral oedema
Skin reactions
Outline the management of high INR in patients on warfarin.
MAJOR BLEEDING: Stop warfarin + IV 5mg vit K + PCC (or FFP)
INR >8.0 + minor bleeding: stop warfarin + IV 1-3 mg vit K + restart warfarin when INR < 5
INR > 8 + no bleeding: stop warfarin + 1-5 mg oral vit K + restart warfarin when INR < 5
INR 5-8 + minor bleeding: stop warfarin + IV 1-3 mg vit K + restart warfarin when INR < 5
INR 5-8 + no bleeding: withhold 1 or 2 doses of warfarin + reduce subsequent maintenance dose
When should diuretics be taken and why?
Any time except the evening because they will be up all night peeing
Which commonly used NSAID is NOT nephrotoxic?
Aspirin
NOTE: it also rarely worsens asthma
Which type of bladder stabilising drugs should be avoided in myasthenia gravis?
Anti-cholinergic (e.g. oxybutynin, solifenacin)
Use mirabegron instead
Which medication can be given as a one-off for acute anxiety?
2 mg diazepam PO
Which parameter is important to monitor in patients on digoxin?
Serum creatinine
Mainly excreted renally, so patients with renal dysfunction are at risk of digoxin toxicity
Which parameter is important to check at baseline and monitor in patients receiving sodium valproate?
LFTs (ALT)
Valproate is associated with hepatotoxicity
What should you keen an eye on when giving a patient IV aminophylline?
ECG - it can precipitate cardiac arrhythmias
What should be checked to identify theophylline toxicity?
Serum theophylline level (18h after commencing Tx)
Target: 10-20 mg/L
NOTE: aminophylline is a stable mixture of combined theophylline + ethylenediamine
When does enoxaparin require dose-adjustment?
eGFR <30 mL/min
Weight <50kg
Which commonly used diabetes drugs can cause hypoglycaemia?
Insulin
Sulphonylureas (e.g. gliclazide)
Thiazolidinediones (e.g. pioglitazone)
List 9 drugs that cause urinary retention?
Opioids Anticholinergics General anaesthetics, Alpha-adrenoceptor agonists, Benzodiazepines (e.g. diazepam), NSAIDs (e.g. ibuprofen), Calcium-channel blockers, Antihistamines, Alcohol.
List drugs classes that can cause confusion.
Opioids (e.g. morphine)
Metoclopramide
Anticholinergics (e.g. oxybutynin, tiotropium)
Glucocorticoids (e.g. prednisolone)
Abx (e.g. co-amoxiclav)
Diazepam
Antipsychotics
Antidepressants
Anticonvulsants
Beta-blockers
How should the dosing of gentamicin be changed if the peak and trough concentrations are too high?
Peak too high –> reduce the dose
Trough too high –> increase interval between doses (giving more time for clearance)
Name two different LMWHs and their prophylactic and treatment doses.
Tinzaparin: 4500 U (prophylactic), 175 U/kg (treatment)
Enoxaparin: 40 mg (prophylactic), 1.5 mg/kg (treatment)
NOTE: enoxaparin 40 mg = 4000 U
List 5 drugs that contribute to hyperkalaemia.
ACEi/ ARB
Heparins (inhibit aldosterone synthesis)
Tacrolimus
Spironolactone/ amiloride
NSAIDs
When should aspirin be stopped before surgery?
7 days
How should patients on warfarin be advised ahead of elective surgery?
Stop warfarin 5 days before surgery
If INR >1.5 on the day before surgery, give 1-5mg vitamin K PO
Which monitoring parameter may rise slightly in patients started on ACE inhibitors?
Creatinine - but a rise < 20% is no cause for concern + Tx should continue (repeat U+E after 1w)
What is the best gauge of whether chronic heart failure treatment (i.e. ACE inhibitors, beta-blockers) are working?
Exercise tolerance
How should the usual dose of insulin in a type 1 diabetic be changed if their blood glucose is being deranged due to the use of steroids?
Increase insulin dose by 10%
When should patients be reviewed after starting a statin?
Measure total cholesterol, LDL + HDL 3 months after starting Tx
Aim for > 40% reduction in non-HDL cholesterol
If failed to achieved –> discuss adherence, consider increasing dose
What medication should you prescribe for a mild CAP?
Amoxicillin 500 mg TDS for 5 days
Penicillin allergy: clarithromycin 500 mg BD for 5 days
What medication should you prescribe for a HAP?
Piperacillin with tazobactam (tazocin) 4.5 g TDS IV
How should acute dystonic reactions be treated?
Procyclidine
Which steroid should be given to patients with an acute exacerbation of COPD?
30 mg prednisolone OD for 5 days
Describe the interaction between warfarin and clarithromycin.
Clarithromycin increases the effect of warfarin (thereby leading to a rise in INR)
How should patients be advised after missing one pill?
Take the missed pill and continue as per usual
They will be protected anywhere in the cycle
Which diabetes drug does simvastatin interact with leading to myotoxicity?
Gemfibrozil
What should be checked and corrected before starting amiodarone?
Serum potassium
Because amiodarone can cause hypokalaemia
How is phenytoin monitored?
Trough level
Therapeutic at 10-20 mg/L
What are the main risks of using metoclopramide?
Cardiac conduction disorders as it causes QTc prolongation (e.g. electrolyte disturbances)
Extra-pyramidal side-effects (avoid if already on an antipsychotic)
What dose of aciclovir should be used to treat shingles in adults?
800mg 5x daily for 7 days
List 2 common drugs that can cause ankle oedema.
CCBs (e.g. amlodipine)
Naproxen
What should you do with a patient’s normal long- and short-acting insulin regimes when you start treating them for DKA?
Stop short-acting
Continue long-acting
Place on fixed-rate insulin infusion
How should you advise patients to take loperamide?
4mg followed by 2mg after each loose stool up to a max of 16 mg/24 h
What monitoring is required in patients taking ciclosporin?
Liver + kidney function
NOTE: it is not myelotoxic
Which opioid is safe to use in renal impairment?
Oxycodone - it is mainly metabolised by the liver
In a patient with DKA, what range of serum K+ warrants giving fluids with KCl?
3.5-5.5 mmol/l - use 0.9% saline + 40 mmol/L of potassium replacement
Name a commonly used NSAID that can cause hepatitis.
Diclofenac
What is the maximum rate at which fluids containing potassium can be given through a peripheral cannula?
10 mmol/hour
NOTE: rates above 20 mmol/hour needs cardiac monitoring
How many mmol of KCl are in 1 L of 0.3% potassium?
40 mmol
How should long-term prednisolone dose be changed in patients who are acutely unwell?
Double it
What is the dose of nebulised adrenaline that should be given in severe croup?
400 micrograms/kg
Why shouldn’t diltiazem and verapamil be used in heart failure?
Worsens fluid retention
NOTE: if AF in heart failure, digoxin should be used
Which anti-epileptic is safest to use in pregnancy?
Lamotrigine
Which are the best anti-epileptics for focal epilepsy?
Lamotrigine
Carbamazepine
In which patients with newly diagnosed T2DM should you avoid using metformin?
Underweight (as it causes appetite suppression)
Creatinine >150 umol/L (risk of lactic acidosis)
In these scenarios, use gliclazide instead
What should be checked before starting treatment with atypical antipsychotic drugs?
Fasting blood glucose
How do you manage a Parkinson’s disease patient who is nil by mouth?
Get an urgent SALT assessment
Consider inserting NG tube
Consider prescribing rotigotine patch
Which medications can be used to reduce secretions in palliative care?
Glycopyrronium
Hyoscine
NOTE: these are usually SC injections
List 5 medications that exacerbate heart failure.
NSAIDs (fluid retention)
Verapamil + diltiazem (negative inotrope + fluid retention)
Pioglitazone (fluid retention)
Flecainide
Cyclizine (fall in cardiac output)
How do you convert from morphine to alfentanil and fetanyl?
Morphine –> Alfentanil (divide by 30)
Alfentanil –> Fentanyl (divide by 5)
Breakthrough fentanyl = 1/8th of daily dose
Which medications should be stopped before surgery?
Insulin
Lithium
Anticoagulants/ antiplatelets
COCP/ HRT
K+ sparing diuretics + ACE inhibitors
Oral hypoglycaemics (metformin)
Perindopril + other ACE inhibitors
Which 2 commonly used drugs should be avoided in peripheral vascular disease?
Beta-blockers
ACE inhibitors
Which medication can be used as an alternative to LMWH in patients with VTE and a phobia of needles?
Apixaban 10mg BD for 7 days
Which medication is used for agitation in palliative care?
Midazolam
NOTE: haloperidol should be used for patients with hallucinations
Which types of seizures can be treated with sodium valproate?
Generalised
Absence (also ethosuximide)
Myoclonic
Tonic
Describe the equivalent doses between prednisolone and hydrocortisone.
5mg prednisolone = 20mg hydrocortisone
What is the maximum dose of lidocaine that can be administered as local anaesthetic?
3 mg/kg without adrenaline
7 mg/kg with adrenaline
In which patients should 5% dextrose be avoided?
Stroke - increased risk of cerebral oedema
Which courses of steroids require weaning?
> 40mg prednisolone daily for 1w
3w Tx
Repeated courses
Which antibiotic is usually used for surgical prophylaxis?
Ceftriaxone 2g IV stat
How should a patient be switched from an insulin infusion to SC insulin?
VRIII should be stopped at breakfast or evening meal only (not at midday meal)
Administer usual dose of mixed insulin.
Allow patient to eat meal as normal.
Stop IV insulin infusion 30 mins later.
