Prescribing Safety Flashcards
What information is important to include on the drug chart if a drug is being used ‘as required’? (2)
- The maximum dose or the maximum frequency
2. The indication
What information is important to include on the drug chart if an antibiotic is prescribed? (2)
- The indication
2. The stop/review date
When is it important to include duration on the drug chart?
If the drug is not long term e.g. antibiotic
If the drug is prescribed in the GP setting
The general rule is don’t use the trade name of drugs, however which drug is an exception to the rule?
Tacrolimus - it is important to use the brand name because switching between brands can cause toxicity
What are the enzyme inducer drugs (use the pneumonic)?
PC BRAS
P - Penytoin C - Carbamezapine B - Barbiturates R - Rifampicin A - Alcohol (chronic excess) S - Sulphonylureas
Whats are the enzyme inhibitor drugs? (use the pneumonic)
AO DEVICES
A - Allopurinol O - Omeprazole D - Disulfiram E - Erythromycin V - Valporate I - Isoniazid C - Ciprofloxacin E - Ethanol (acute intoxication) S - Sulphonamides
What is an example of an enzyme inibitor interaction?
Warfarin and Erythromycin
Erythromycin as an enzyme inhibitor can increase the drug concentration of Warfarin therefore causing the INR to dangerously increase, if the Warfarin is not reduced
Why are patients on long-term steroids unable to mount an adequate sick response?
They have adrenal atrophy
What should a patient on long-term steroids receive before surgery and why?
IV steroids at induction of anaesthesia
This is because they are unable to mount the stress response therefore would have profound hypotension otherwise
It is similar to patients taking double the dose of their steroids on sick days
Which drugs should be stopped before surgery? ( used the pneumonic)
I LACK OP
I - Insulin L - Lithium A - Anticoagulants/antiplatelets C - COCP/HRT K - K-sparing drugs
O - Oral hypoglycaemics
P - Perindopril and other ACE-inhibitors
When do you stop the COCP/HRT before surgery?
4 weeks before surgery
When do you stop Lithium before surgery?
Day before surgery
When do you stop potassium-sparing diuretics before surgery?
Day of surgery
When do you stop ACE inhibitors before surgery?
Day of surgery
When do you stop anticoagulants (inc prophylaxis dose) and antiplatelets?
Variable between hospitals and operations (some are even continued through the operation)
When should Oral hypoglycaemics be stopped before surgery?
Variable between hospitals and operations
Why should Oral hypoglycaemics be stopped before surgery? What should be done instead
Patients are nil by mouth before surgery therefore should not take metformin as it may cause lactic acidosis
A sliding scale should be used instead with hourly blood glucose monitoring and adjusting as appropriate (tighter control)
What is the pneumonic to help with prescribing?
PReSCRIBER
What does PReSCRIBER stand for?
P - Patient details Re - Reaction (i.e. allergy plus the reaction) S - Sign the front of the chart C - Contraindications R - Route for each drug I - Intravenous fluids if needed B - Blood clot prophylaxis if needed E - antiEmetics if needed R - pain Relief if needed
How many pieces of patient identifying info needs to be on a drug chart and give examples of suitable ones?
3 are needed:
Patient name
DOB
Hospital number
Which two drugs contain penicillin, in a way which is not obvious?
Co-amoxiclav - amoxicillin and clavulanic acid
Tazocin - pipercillin and tazobactam
What are the 4 main groups of drugs, that i must know the contraindications for?
- Drugs that increase bleeding (anticoagulants, antiplatelets)
- Steroids
- NSAIDs/Aspirin
- Anti- hypertensives
In which patients are antiplatlets/anticoagulants contraindicated?
Bleeding
Suspected bleeding
At risk of bleeding
Give an example of why a patient might be at risk of bleeding
Prolonged prothrombin time due to liver disease
What pneumonic can be used for the side effects of steroids?
STEROIDS
What does the STEROIDS pnuemonic stand for?
S - Stomach ulcers T - Thin skin E - oEdema R - Right and Left heart failure O - Osteoporosis I - Infection (inc Candida) D - Diabetes (commonly causes hyperglycaemia and uncommonly progresses to diabetes) S - cushing's Syndrome
What is the ‘safety considerations’ pneumonic for NSAIDs?
NSAID
What does the NSAID pneumonic stand for?
N - No urine (i.e. renal failure) S - Systolic dysfunction (i.e. heart failure) A - Asthma I - Indigestion (any cause) D - Dyscrasia (clotting abnormality)
Why is Aspirin not subject to the same level of caution as NSAIDs used for pain management?
Because although it is an NSAID, it is not used at relatively low doses for the management of cardiovascular and cerebrovascular disease which is not necessary for those extra precautions
What are the 3 anti-hypertensive side effect categories you should always classify in?
- Hypotension
- Mechanism: Bradycardia or Electrolyte disturbance
- Individual drug
Which anti-HTNs can cause hypotension?
All of them
What is the earliest symptom of hypotension?
Postural hypotension
Which antihypertensives cause bradycardia?
Beta blockers (and some calcium channel blockers)
Which CCBs have a bradycardia effect and why?
The non-dihydropyridines - because they have inhibitory effects on the SAN and AVN
What are the non-dihydropyridines useful for treating?
Hypertension, reduces oxygen demand, and helps to control the rate in tachyarrhythmias
Give drug examples of non-dihyrdropyridine (2)
Diltiazem
Verapamil
What is the effect of the dihydropyridine CCBs?
Peripheral vasodilators + have very little effect on the myocardium
What are the dihydropyridine CCBs used for? (3)
- Hypertension
2. Post-intracranial haemorrhage associated vasospasm 3. Migraines
Which anti-HTNs cause electrolyte disturbance?
- ACE- inhibitors
2. Diuretics
4 individual anti-HTN drugs have their own side effects - name the 4 drugs
- ACE inhibitors
- Beta blockers
- CCBs
- Diuretics
Give an example of dihydropyridine drugs (3)
- Amlodipine
- Nifedipine
- Nicardapine
These end in -pine
What is the individual side effect of ACE-Inhibtors?
Dry cough
What are the individual side effects of Beta blockers? (2)
Wheeze in asthmatics
Worsening of acute heart failure (but help in chronic heart failure)
What is the individual side effect of CCBs? (2)
Peripheral oedema and flushing
What is the individual side effect of Diuretics? (3)
- Renal failure
- Thiazide diuretics can cause gout
- Potassium-sparing diuretics can cause gynaecomastia
Name an example of a thiazide diuretic
Bendroflumethiazide
Name an example of a potssium-sparing diuretic
Spironolactone
If a patient is Nil by mouth, can they still recieve their oral medication before surgery?
Yes they can and should
If a patient is vomiting a lot how should you give the antiemetic?
non oral: i.e. IV, IM, SC
NOTE: cyclizine and metoclopramide doses dont change regardless of the route
IV fluid replacement - you always give 0.9% saline except in which 4 cases?
- Hypernatraemic
- Hypoglycaemic
- Ascites
- Shocked from bleeding
What replacement fluid do you give if someone is hypernatraemic?
5% dextrose
What replacement fluid do you give if someone is hypoglycaemic?
5% dextrose
What replacement fluid do you give if someone has ascites? and why?
Human-albumin solution (HAS) - the albumin maintains oncotic pressure (the higher sodium content in 0.9% saline will worsen ascites)
What replacement fluid do you give if someone is shocked from bleeding?
Blood transfusion (but give crystalloid first if no blood is available)
If someone is tachycardic or hypotensive how much /how fast do you give replacement fluids? (what about if they have heart failure?)
500ml bolus immediately
if HF then 250ml bolus immediately
How much/how fast do you give replacement fluid if they are only oliguric (and it is not due to urinary tract obstruction?)
1L over 2-4 hours
In the following scenarios state roughly how fluid depleted each individual is:
- reduced urine output (<30ml/h)
- reduced urine output + tachycardia
- reduced urine output + tachycardia + shocked
- 500ml depleted
- 1L depleted
- > 2L fluid depleted
What is the max rate of infusion for IV potassium?
10 mmol/hr
How much maintenance fluids do adults vs elderly require as a general rule?
adults 3L IV fluids/ 24 hours
elderly 2L IV fluids/24 hours
What bags of fluid would you usually give for maintenance?
1 salty 2 sweet
(remember sweet tooth)
1 L of 0.9% saline
2 L of 5% dextrose
With a normal potassium level, how much potassium is needed per day in the maintenance fluids and how do you administer this?
adults need 40 mmol of K+ per day
Put 20 mmol KCl in 2 of the maintenance fluids bags
How fast do you give maintenance fluids in adults vs elderly?
adults 3L /24 hours - therefore 8 hourly
elderly 2L/12 hours - therefore 12 hourly
What do most pts coming into hospital receive for VTE prophylaxis? (2)
LMWH e.g. dalteparin 5000 units daily SC
and compression stockings
Which pts should not be prescribed compression stockings?
Those with peripheral arterial disease (indicated by abscent foot pulses)
What might happen if a patient with peripheral arterial disease is prescribed compression stockings?
Acute limb ischaemia
In which patients (2) should the antiemetic metoclopramide be avoided? why?
- Parkinson’s disease as it is a dopamine antagonst so can exacerbate symptoms
- Young women - due to risk of dyskinesia (esp acute dystonia)
Which antiemetics can you give if a patient is nauseated? (3) - include the dose and route
Cyclizine 50 mg 8 hourly IM/IV/oral
Metoclopramide 10mg 8 hourly IM/IV (if HF)
Ondansetron 4mg or 8mg 8 hourly IV/oral
When should Cyclizine be avoided and why?
In HF as it causes fluid retention
Which antiemetics can you give if a patient is NOT nauseated?
Cyclizine 50 mg UP TO 8 hourly (IV/IM/oral)
Metoclopramide 10mg UP TO 8 hourly (IM/IV) if HF
these are given PRN if not nauseated
Which analgesic do you give regularly if there is no pain?
NONE! if there is no pain, it shouldnt be regular, but PRn
Which analgesic do you give as required if there is no pain?
Paracetamol 1g up to 6 hourly oral
Which analgesic do you give regularly if there is mild pain?
Paracetamol 1g 6 hourly oral
Which analgesic do you give as required if there is mild pain?
Codeine 30 mg up to 6 hourly oral
Which analgesic do you give regularly if there is severe pain?
Co-codamol 30/500, 2 tablets 6 hourly oral
Which analgesic do you give as required if there is severe pain?
Morphine sulfate (10mg/5mL) 10 mg up to 6 hourly oral
Draw the table of analgesic choices
(see page 10 of PSA book)
How does oramorph come?
A a liquid
When are NSAIDs used in the analgesic choices?
At any stage they can be introduced regularly or PRN if not contraindicated
What is the first line analgesic for neuropathic pain?
Amitriptyline 10 mg oral nightly or pregabalin 75 mg oral 12 hourly
What is the maximum dose of paracetamol in patients >50kg vs <50kg?
> 50kg - max is 4g in 24 hours (this is 1g 6 hourly)
<50kg -max is 2g in 24 hours (this is 500mg 6 hourly)
What is a common mistake leading to overprescribing paracetamol?
Giving co-codamol and paracetamol
What are the 3 causes of a microcytic anaemia?
- Iron deficiency
- Thalassaemia
- Sideroblastic anaemia
What are the 4 causes of normocytic anaemia?
- Anaemia of chronic disease
- Acute blood loss
- Haemolytic anaemia
- Renal failure (chronic)
What are the 6 causes of megaloblastic anaemia
- B12 deficiency
- Folate deficiency
- Liver disease
- Excess alcohol
- Hypothyroidism
- Hamatological diseases beginning with M -myeloproliferative, myelodysplastic, multiple myeloma
Which type of anaemia is pernicious anaemia and why?
Macrocytic - becasue in pernicious anaemia there if a deficency of B12
What are the three causes of neutrophilia (high neutrohils)?
- Bacterial infection
- Tissue damage (inflammation, infarct, malifgnancy)
- Steroids
What are the 4 causes of neutropenia (low neutrophils)?
- Viral infection
- Clozapine (antipsychotic)
- Carbimazole (antithyroid)
- Chemotherapy or radiotherapy
Thrombocytopaenia can can be caused by reduced production or increased destruction - what are the 3 causes of reduced production?
- infection (viral)
- drugs e.g. penicillamine
- myelodysplasia, myelofibrosis, myeloma
Thrombocytopaenia can can be caused by reduced production or increased destruction - what are the 5 causes of increased destruction?
- Heparin
- Hypersplenism
- DIC (disseminated intravascular coagulation)
- Idiopathic Thrombocytopaenic purpura
- HUS (haemolytic uraemic syndrome)/TTP (thromboric thrombocytopaenic purpura)
What are the reactive causes of thrombocytosis (high platelets)? (3)
- Bleeding
- Tissue damage (infection/inflammation/malignancy)
- Post-splenectomy
What is the primary cause of thrombocytosis (high platelets)?
Myeloproliferative disorders
What types of hyponatraemia can hypothyroidism cause?
Euvalaemic and Hypervolaemic
Which drugs tend to cause SIADH?
Carbamezapine and antipsychotics
Hypernatraemia causes all begin with D - what are they? (4)
- Dehydration
- Drips (too much IV saline)
- Drugs
- Diabetes insipidus
What are the pneumonics for Hypokalaemia and Hyperkalaemia and what is a good way to remember which pneumonic goes with which?
Hypokalaemia: DIRE
Hyperkalaemia: DREAD
(I dread TOO MUCH work)
List the causes of Hypokalaemia
D - drugs (loop and thiazide diuretics)
I - inadequate intake or intestinal loss (diarrhoea/vomiting)
R - renal tubular acidosis
E - endocrine (Cushing’s and Conn’s syndromes)
List the causes of Hyperkalaemia
D - Drugs (potassium sparing diuretics and ACE-inhibitors)
R - Renal failure
E - Endocrine (Addisons’s disease)
A - Artefact (very common due to clotted sample)
D - DKA (but when insulin is given the K+ drops)
What two things can a raised urea indicate?
Kidney injury OR an upper GI bleed
Why does urea increase in an upper GI bleed?
Because it is a breakdown product of amino acids e.g. globin chains in haemoglobin)
Or the haemoglobin in the blood can be broken down by gastric acid and then the urea absorbed into the bloodstream (this is what happens if someone has a bloody steak)
If a patient has a raised urea and is not dehydrated what should this prompt you to look at and why?
Their haemoglobin because if it has dropped the patient has probably had an upper GI bleed
What are the pre-renal causes of acute kidney injury? (4)
- dehydration
- sepsis
- blood loss
- renal artery stenosis
What are the intrinsic causes of acute kidney injury?
INTRINSIC Ischaemia (due to pre-renal AKI causing acute tubular necrosis) N - nephrotoxic antibiotics Tablets (ACEi , NSAIDs) Radiological contrast Injury (rhabdomyolysis) Negatively birefringent crystals (gout) Syndromes (glomerulonephritidies) Inflammation (vasculitis) Cholesterol emboli
What are the nephrotoxic antibiotics?
Gentamycin
Vancomycin
Tetracyclines
Sometimes in severe pre-renal AKI, creatinine can also rise - if this happens how can you differntiate from non pre-renal causes?
urea x 10 - if it exceeds the creatinine then it means a relatively greater increase in urea compared to creatinine which suggests pre-renal aetiology
What are the 4 markers of hepatocyte injury or cholestasis?
- Bilirubin
- ALT
- AST
- ALP
What are the markers of synthetic function? (2)
Albumin
Vitamin K-dependent clotting factors
Which 2 investigations give an idea of the vitamin K-dependent clotting factors?
Prothrombin time
INR
How do you divide up the causes of post-renal causes of AKI?
In lumen
In wall
External pressure
What are the in lumen causes of a post-renal AKI? (2)
- Stone
2. Sloughed papilla
What are the In wall causes of a post renal AKI? (2)
- Tumours:
Renal cell carcinoma
Transitonal cell carcinoma - Fibrosis
What are the External pressure causes of a post renal AKI? (4)
BPH
Prostate cancer
Lymphadenopathy
Aneurysm
What is the pattern of LFT derrangement in pre-hepatic jaundice?
Raised bilirubin on its own
What is the pattern of LFT derrangement in intrahepatic jaundice?
Raised bilirubin
raised ALT/AST
What is the pattern of LFT derrangement in post-hepatic jaundice?
Raised bilirubin
raised ALP
What are the causes of pre-hepatic jaundice? (3)
Haemolysis
Gilberts syndrome
Crigler-Najjar syndrome
What are the causes of intrahepatic jaundice? (6)
Fatty liver
Hepatitis
Cirrhosis
Malignancy (primary or secondary)
Metabolic: Wilson’s disease / Haemochromatosis
Heart Failure (causing hepatic congestion)
In the intrahepatic causes of jaundice - what can be the causes of hepatitis and cirrhosis?
Alcohol
Viruses (Hep A-E, CMV, EBV)
Drugs (paracetamol overdose, statins, rifampicin)
Autoimmune causes: PBC, PSC, autoimmune hepatitis
What are the causes of post-hepatic jaundice? (using the structure: In lumen, In wall, external pressure)
In lumen: stone (gallstone), drugs causing cholestasis
In wall: Tumour (cholangiocarcinoma), PBC, PSC
External pressure: Pancreatic or gastric cancer, lymph node
Which drugs cause cholestasis? (5)
- Flucloxacillin
- Co-Amoxiclav
- Nitrofurantoin
- Steroids
- Sulphonylureas
Using the pneumonic ALKPHOS, list the causes of raised ALP
Any fracture Liver damage (post-hepatic) K cancer Paget's disease of the bone / Pregnancy Hyperparathyroidism Osteomalacia Surgery
Causes of primary hypothyroidism
Hashimotos thyroiditis
Drug induced hypothyroidim
Causes of secondary hypothyroidism
Pituitary tumour
damage
Primary hyperthyroidism causes
Grave’s disease
Toxic nodular goiter
drug induced hyperthyroidism
Secondary causes of hyperthyroidism
Pituitary tumour
On CXR how do you check for rotation?
The distance between the spinous processes and the clavicle should be equal
How can you check for good inspiration on CXR?
The 7th anterior rib should transect the diaphragm
white areas on CXR - diagnose the following:
- unilateral and solid
- unilateral and fluffy
- bilateral and fluffy
- bilateral and honeycomb
- pleural effusion
- pneumonia
- pulmonary oedema
- pulmonary fibrosis
If you spot cardiomegaly, pleural effusion or pulmonary oedema on CXR what else should you check for?
ABCDE signs of HF
A - alveolar oedema (bats wings)
B - Kerley B lines (interstitial oedema)
C - cardiomegaly
D - upper lobe diversion (vessels in the upper zone are larger than the vessels in the lower zone)
E - Effusions
What does air under the right hemi-diaphragm suggest?(2)
Bowel preforation
recent surgery
What is sail sign and what does it suggest?
Sail sign = a triangle behind the heart
suggests left lower lobe collapse
If the apices are not clear, what DDx should you consider (2)?
TB apical tumour (pancoast)
What type of breathing do you get in type 1 resp failure vs type two resp failure?
Type 1 = fast / normal breathing
Type 2 = slow/shallow breathing
What causes type I resp failure?
Anything that damages the heart of lungs causing SOB
What causes type 2 resp failure?
‘blue-bloaters’ of COPD
neuromuscular failure
restrictive chest wall abnormalities
What causes respiratory alkalosis?
rapid breathing - either from disease or anxiety
What causes respiratory acidosis?
The same causes as type I resp failure
What causes metabolic alkalosis?
Vomiting
Diuretics
Conn’s syndrome
What causes metabolic acidosis?
anion gap high: lactic acidosis, DKA, ethanol/methanol/ethylene glycol poisoning), renal failure (due to uraemia)
How big does that PR interval need to be for first degree heart block?
> 1 large square (>5 small squares)
If QRS >3 small squares what does this suggest?
Bundle branch block
How can you detect LVH on ECG?
Add the largest deflection in V1 to the largest deflection in V6 - if the sum is >3.5 large squares then LVH
Other than ischaemia/infarction, what else can cause ST depression?
Digoxin - ST segment down-sloping in all leads
How can you detect hyperkalaemia by T waves on ECG
If the height f the T waves is >2/3 the QRS height throughout the ECG then hyperkalaemia present
T wave inversion in which leads suggests old infarction/LVH?
leads aVR and lead I (top middle two leads)
Which are the drugs which commonly need monitoring?
Lithium Digoxin Theophylline Phenytoin Gentamicin Vancomycin
If there is an adequate response to the drug, but the serum level is high what should you do? However which drug is an exception to this and what do you do instead?
Decrease the dose
Gentamicin is an exception - instead of omitting the drug, you decrease the frequency by 12 hours rather than reducing the dose e.g. changing from every 24 hours to every 36 hours
If there serum drug level is very high and there is toxicity, what might you consider doing?
Omitting the drug for a few days
If toxicity is evident- what are the 3 options?
- stop drug
- supportive measures (usually IV fluids)
- give antidote (if available)
What are toxicity features of digoxin? (4)
- confusion
- nausea
- visual halos
- arrhythmias
What are the toxicity features of lithium? (early (1) , intermediate (1), late(5)
Early: tremor
Intermediate: tiredness
Late: Arrhythmias, seizures, coma, renal failure, diabetes insipidus
What are the toxicity features of phenytoin?
Gum hypertrophy Ataxia Nystagmus Peripheral neuropathy Teratogenicity
What are the toxicity features of gentamicin?
Ototoxicity and nephrotoxicity
What are the toxicity features of vancomycin?
Ototoxicity and nephrotoxicity
If there is a patient on Warfarin and there is a major bleed causing hypotension of bleeding into a confined space e.g. brain or eye - what 3 things should be done?
- Stop warfarin
- Give IV Vit K (5-10 mg)
- Give prothrombinase complex
If INR is 5-8 and there is No bleeding - what do you do?
Omit warfarin for 2 days then reduce dose
If INR is >8 and there is no bleeding what do you do?
Omit warfarin and give 1-5mg PO Vit K
If INR is 5-8 and there is minor bleeding what do you do?
Omit warfarin and give 1-5mg IV vitamin K
If INR >8 and there is minor bleeding what do you do?.
Omit warfarin and give 1-5mg IV vitamin K
What is the triad of symptoms that means opioid overdose until proven otherwise?
- reduced GCS
- Pinpoint pupils
- Respiratory depression
What is the triad which points to anticholinergic overdose?
DDD
Dry
Dilated
Delirious
What is the fun rhyme for anticholinergic overdose?
Mad as a hatter (confused and agitated) Hot as hell (hyperpyrexia) Blind as a bat (dilated pupils) Dry as a bone (dry mouth, eyes and retention) Red as a beet (flushing)
What is the most common cause of anticholinergic overdose?
Tricyclic antidepressants
Which medications can cause serotonin syndrome?
SSRIs Tricyclic antidepressants Monoamine oxidase inhibitors Opioids Amphetamines MDMA Cocaine Ondansetron
What medication can help in Serotonin syndrome?
Benzodiazepines - helps the agitation and muscle rigidity
What should be avoided in serotonin syndrome and why?
IV fluids due to risk of hyponatraemia
if you do need to use fluids use hypertonic saline
What time of day should ACE inhibitors be taken and why?
Night time because they can cause postural hypotension
Write the insulin prescription for hyperkalaemia
Actrapid 10 Units in 100ml of 20% dextrose, over 30 mins
What do you need to be careful of when starting a patient on Carbamezapine?
SIADH
When would Metformin not be used first line in T2DM??
If Creatinine is >150 as it can cause lactic acidosis
Why should Metformin be used first line in overweight patients?
It causes appetite suppression
Give 4 examples of sulphonylureas for diabetes?
- Gliclazide
- Tolbutamide
- Glipizide
- Glipenclamide
What is the mechanism of action of Metformin?
Helps increased sensitivity to insulin (encourages cells to respond better to insulin and take up more glucose from the blood stream)
What is the mechanism of action of sulphonylureas?
Stimulate production of insulin from the pancreas
Why is Glibenclamide a less appropriate starting drug for T2DM?
It is a longer-acting sulphonylurea
What time of day/when should gliclazide be taken?
With the first meal
What is the mechanism of NSAIDs causing stomach ulcers?
They inhibit prostaglandin synthesis which is needed for gastric mucosal protection from acid- hence inflammation and ulceration
What is the mechanism of streroids causing stomach ulcers?
They inhibit gastric epithelial renewal
What are the symptoms of mild vs moderate vs severe lithium toxicity?
mild - tremor
moderate - lethargy
severe - seizures, renal failure, coma, arrhythmia
If the dose of Lithium has not been changed why might the plasma levels increase? (2)
Reduced breakdown
Reduced excretion
What can cause reduced breakdown of Lithium?
Cytochrome P450 enzyme inhibitors
- check for AO DEVICES
Which drugs can cause reduced excretion of Lithium? (4)
ACE- inhibitors
Diurectics (in particular thiazide diuretics e.g. bendroflumethiazide)
NSAIDs
If a diuretic must be given whilst a patient is on Lithium, which one should be given?
Loop diuretics e.g. furosemide
What dose of adrenaline is give IV during cardiac arrest?
1mg or 1 : 10,000 adrenaline
In pulmonary oedema, when should patients be considered for NIV?
If they remain hypoxic on 100% oxygen vis a non-rebreathe mask
Over what time frame does angio-oedema caused by ACE-inhibitors typically occur?
Over months - it takes time before it appears as the bradykinin needs time to build up first
What two things are important to monitor with ACE-inhibitors and when do you do the bloods?
K+ and renal function
Blood test 1-2 weeks after starting
Why shouldnt’ statins be used in patients with active liver disease?
The metabolism of the statin may be affected
What is a side effect of statins?
Myositis - patients can get muscle cramps - unusual aches and pains
What time of day are statins taken?
Night time
What is the dietary restriction for patients taking a statin and why?
Grape fruit should be avoided because it contained polyphenolic compounds that can be an enzyme inhibitor (of CYP3A4) and so increases statin toxicity
Which antibiotic, would make you with-hold statins during the time of antibiotic treatment and why?
Clarithromycin as it is a CYP3A4 inhibitor and so increases the toxicity and associated side effects of statins
Why should patients on long courses of steroid never have the steroid stopped suddenly?
Risk of Addisonian crisis
What card should those on long term steroids carry with them?
A steroid therapy card
Patients on steroids are at risk of hypertension or hypotension?
Hypertension
What should be checked before starting methotrexate?
FBC
Liver function
Renal function
Describe the monitoring of methotrexate once started
FBC, LFTs and renal function tests should be carried out every 1-2 weeks until the therapy is stabilised
Then they should be checked ever 2-3 months
What safety net is important to give to patients on methotrexate?
Be cautious of sore throat
- because they can get neutropaenia
How often is methotrexate taken?
once a week
What is a potential side effect of methotrexate?
Pulmonary toxicity (breathlessness, dry cough, fatigue)
What group of medications shouldn’t be used at the same time as methotrexate and why? Give 2 examples of such drugs
Folate antagonists - they will increase the folate antagonism (as methotrexate is also one) - this can put the patient at risk of bone marrow suppression and subsequent neutropaenic sepsis
Examples: Trimethoprim and Co-trimoxazole
What needs to be monitored for patients on Olanzapine?
Lipids and wieght
Describe the monitoring of Olaanzapine and explain how this is different to other anti-psychotics?
Weight and Lipids Olanzapine: Measure weight and lipids at: 1. Baseline 2. Every 3 months for the 1 year 3. Annually Other antipsychotics: measure at base line, then at 3 months and then annually
Fasting Glucose Olanzapine: Measure fasting blood glucose at: 1. Baseline 2. at 1 month 3. Every 4-6 months
Other antispychotics: measure at baseline, at 4-6 months and then annually
Why is an ECG sometimes needed in patients taking Olanzapine?
Because Olanzapine can cause a prolonged QTc interval
In which patients would you consider doing an ECG in if they are started on Olazapine?
Those with cardiovascular risk factors or a personal history of cardiovascular disease
If Olanzapine is stopped in the first ____ there is a considerable risk of relapse
1-2 years
How do you decide between codeine and tramadol as the weak opioid to use in the WHO ladder?
Dependent on the side effect profile
- Codeine - has more constipation side effect
- Tramadol has more hallucinogenic and agitation side effect (particularly in the elderly so you want to avoid in the elderly )
Some people with penicillin allergy may have cross reactivity and therefore also be allergic to which other antibiotic groups?
Cephalosporins
Carbapenems
What is first line treatment for hospital acquired pneumonia?
Piperacillin and Tazobactam (Tazosin- but dont write tazosin on a drug chart)
Why can’t you use CURB-65 score with Hopsital acquired pneumonia?
It is only for community acquired pneumonia - remember the purpose of the score is to determine if they are admitted to hospital so if they have a HAP, they are already in hospital
In terms of reviewing IV antibiotic therapy - what is the rule of thumb?
Review NO MORE than 3 days after initiating as most patient will then be able to step down to oral antibiotics
How do stimulant laxatives work?
Promote peristalsis
Name 2 examples of stimulant laxatives
Senna and Bisacodyl
What is the difference in the MOA of senna and bisacodyl?
Senna stimulates colonic nerves to cause peristalsis
Bisacodyl stimulates both colonic and rectal nerves to cause peristalsis
Give an example of a stool softner laxative
Docusate
What is the MOA of Docuate?
It is a surface-wetting agent - reduces the surface tension of the stool allowing water to more easily penetrate the stool and soften it
List the 4 types of laxative
Bulk forming
Stool softeners
Stimulant
Osmotic
Give 2 examples of osmotic laxatives
Lactulose
Macrogol
What is the MOA of osmotic laxatives?
Increases fluid in the large bowel which produces distention leading to stimulation of peristalsis
What is important to note regarding the administration of macrogol
They require a large volume of fluid to drink and if not enough fluid is drunk it can lead to dehydration
What might lead you to avoid osmotic laxatives?
If the patient is already bloated
When might you avoid stimulant laxatives?
If the patient is in bowel obstruction
Give an example of a bulk forming laxative
Isphagula Husk
What is the MOA of bulk forming laxatives?
Retain fluid within the stool and increases faecal mass which stimulates peristalsis (they also have stool softening effects)
State the time it take to have effect for each of the 4 groups of laxative
Bulk forming laxatives - 2-3 days
Stool softeners - 12-72 hours
Stimulant - 6- 12 hours
Osmotic 2-3 days
How do you know whether to put an analgesic in the ‘as required’ section or the regular section?
If they are in constant pain then make it regular, if the pain is sometimes there then ‘as required’
If a patient wants immediate relief of indigestion what would you prescribe?
Antacid
Note:PPIs (e.g. omeprazole) and H2 antagonists e.g. Ranitidine improve dyspepsia but are not immediate
Which medication has gum hypertrophy as a side effect?
Ciclosporin
What electrolyte disturbance can SSRIs cause?
Hyponatraemia
Why should COPD patients who are chronic CO2 retainers have reduced O2?
Normally there are two drivers for increased respiration - hypoxia and hypercapnoea
In chronic retainers they have lost their hypercapnic drive
and so rely on hypoxia to keep them breathing - hence you don’t want to give them too much oxygen
What o2 sats should you aim for in a COPD chronic retainer?
88-92%
>95% can lead to a reduction in resp rate
If a patient is conscious and hypoglycaemic, what should be the first treatment option?
10-20g of glucose by mouth e.g. orange juice or biscuits
How do you treat hypoglycaemia if the patient is unconscious?
IM glucagon injection
When would you use IV glucose and what %?
If the IM glucagon doesnt work, 10% IV glucose can be used
What is the effect of NSAIDs on the kidneys?
NSAIDs Inhibit prostaglandins but prostaglandins normally dilate the afferent vessels promoting flow into the kidney but inhibiting prostaglandin through NSAIDs causes reduces renal perfusion
What is the effect of ACE-inhibitors on the kidneys?
ACE-i causes the efferent blood vessels to dilate - this reduces the hydraulic pressure in the glomerulus and therefore reduces glomerular filtration
Why should NSAIDs and ACEi never be prescribed together?
NSAIDs constrict the afferent vessels, ACEi dilate the efferent vessels - both occuring together reduces the pressure in the kidney too much and GFR tails off + the kidney is under perfused
Why can’t oxybutynin be used in myasthenia gravis?
Because in myasthenia gravis they produce anti-acetylcholine receptor blockers and so the medication (which is an anti-muscarinic) wouldn’t work
In the WHO ladder, what are you options for weak opiates?
Codeine
Tramadol
Compare and contrast codeine and tramadol and when to use each
Codeine - side effects are resp depression, reduced consciousness and pinpoint pupils + is more constipating than tramadol
Tramadol - agitation and hallucinations (particularly in the elderly)
If a patient has diarrhoea you may be more inclined towards codeine
When should you put the stop/review for antibiotics date if unsure?
oral antibiotics - after 5 days
iv antibiotics - after 3 days
Is St John’s wort an enzyme inducer or inhibitor?
Enzyme inducer
What is the first line drug for GAD?
Sertraline 25mg
(although it is not licensed on the BNF for GAD, NICE recommends it as first line as it more cost effective than citalopram and escitalopram)
In which trimester of pregnancy are NSAIDs the most dangerous?
3rd trimester - as prostaglandins keep open the ductus arteriosus and NSAIDs inhibit prostaglandin synthesis meaning it could prematurely close
If a patient has impaired renal function, what should happen to their metformin?
Stop the metformin (it is largely cleared by the kidneys and you dont want it to accumulate due to risk of lactic acidosis)
If a patient has impaired renal function, what should happen to their digoxin?
Reduce the dose - it is renally cleared and you don’t want it to accumulate which can lead to digoxin toxicity
What information shouldbe communicated with patients regarding bisphosphonates
Take on empty stomach -at least 30 minutes before breakfast (or any other oral tablet)
Stand/sit upright for 30 minutes after taking the tablets
What must patients be warned about before taking adenosine?
Chest tightness - it may feel like they are about to die
How long do the effects of adenosine last?
1-2 minutes
What effect does adenosine have on BP?
Lowering effect
Why does furosemide increase the risk of lithium toxicity?
Furosemide decreases GFR and lithium is cleared renally (Lithium does not involve the CYP 450 enzymes)
What drug should be prescribed to stabilise the myocardium in hyperkalaemia?
Calcium gluconate
(not calcium carbonate)
In ACS, why do you give metoclopramide in addition to morphine?
Due to Opioid-induced nausea
In maintenance fluids what is the daily intake of water?
20-25mL/kg
In maintenance fluids, what is the daily intake of potassium?
1mmol/kg
In maintenance fluids, what is the daily intake of sodium?
1mmol/kg
In maintenance fluids, what is the daily intake of chloride?
1mmol/kg
In maintenance fluids, what is the daily intake of glucose?
50-100g (to limit starvation ketosis)
Which diuretic causes dyslipidaemia?
Bendroflumethiazide
How does clopidogrel work?
Blocks the ADP-mediated activation of the glycoprotein GPIIb/IIIa complex which normally causes platelets to aggregate
What is the safest prescription of analgesia for a patient with chronic alcoholic liver disease?
Paracetamol 500mg PO four times a day (notice it is not 1g 4 times a day - the dose is reduced to avoid hepatotoxicity)
Why are NSAIDs not safe to use in patients with alcoholic liver disease?
Patients with alcoholic liver disease may have clotting abnormalities and NSAIDs would further increase the risk of bleeding
Why are opioids not safe in patients with alcoholic liver disease?
They may precipitate hepatic encephalopathy
Which group of medications exacerbate psoriasis?
Beta blockers
Which anti-emetics are preferred in pregnancy for hyperemesis gravidarum?
antihistamines e.g. cyclizine
Which statins should not be prescribed with warfarin?
Fluvastatin
Rosuvastatin
Why should patients taking metronidazole avoid alcohol?
They may develop a disulfiram-like reaction
What is the definition cut off values for gestational diabetes?
Fasting plasma glucose > or = 5.6mmol/L
OR
Two hour plasma glucose > or = 7.8
Does Gliclazide cause constipation or diarrhoea?
diarrhoea
VTE prophylaxis (orthopaedic surgery) - what are the options?
- RIvaroxaban - 5 weeks (hip surgery), 2 weeks (knee surgery)
- LMWH for 10 days followed by aspirin for 28 days
- LMWH for 28 days with anti-embolism stockings (until discharge)
How do heparins contribute to hyperkalaemia?
They inhibit aldosterone synthesis
How does Tacrolimus cause hyperkalaemia?
Reduced excretion Note ciclosporin (another calcineurin inhibitor also causes hyperkalaemia)
Antiplatelets such as aspirin are stopped up to how many days before surgery?
7
What is the exception for witholding antiplatelets before surgery?
If they have recently had PCI/vascular stent - the risk of thrombosis is still high
Why should allopurinol be stopped if a patient develops AKI?
It can accumulate as it is renally cleared
Why do SSRIs cause hyponatraemia?
Via SIADH
At what eGFR should nitrofurantoin be avoided?
<45
If INR is >1.5 on the day before surgery, what prescription is recommended to bring INR down quickly?
Phytomenadione (Vitamin ) 1-5mg PO
note: IV can also be used
How should the rivaroxaban be taken - i.e. the instructions to the patient?
Take it with food
What should happened to the contraception if a woman is on POP or COCP and needs to take topiramate (for migraine)? and why/.
Switch to an alternative form of contraception (until at least 4 weeks after stopping the topiramate) because topiramate is an enzyme inducing drug
What side effect can commonly occur with co-amoxiclav treatment?
jaundice due to cholestasis
What % rise in creatinine is to be expected when starting an ACE inhibitor?
<20% - this would not require a change in prescription
What should be monitored to check that an ACE inhibitor is having beneficial effect in heart failure treatment?
Exercise tolerance
What are the most serious adverse effects of ciclosporin? (2)
Nephrotoxicity
Hypertension
How do you know if the atorvastatin dose needs to be changed after commencing due to QRISK score?
No dose change if after 3 months of treatment a >40% reduction in non-HDL cholesterol has occurred