PSA Flashcards
Why must clozapine be re-titrated after 48 hours?
failure to do so increases the risk of orthostatic hypotension, which may be accompanied by cardiac or respiratory arrest
Do ACEi doses need to be retitrated and why?
Yes, they should be retitrated gradually to avoid first dose hypotension
What does oral ferrous/iron interact with?
Interacts with quinolones (e.g. ciprofloxacin), reducing their absorption
Which medications should be avoided in patients with G6PD deficiency?
Aspirin Anti-malarials Nitrofurantoin Ciprofloxacin Co-trimoxazole
- haemolytic anaemia
What condition can cause massively raised CK in patients on statins?
Rhabdomyolysis
What are the CYP450 inhibitors?
Diltiazem
Can you take diltiazem with a statin?
diltiazem is a CYP450 inhibitor and increases the concentration of statins in serum.
should reduce the dose of statin when prescribing alongside diltiazem
What does the COCP interact with to reduce its efficacy? (inducer or inhibitor)
CYP450 inducers increase the rate of metabolism of COCP and reduce its bioavailability and therefore its efficacy
Can you give miconazole with warfarin?
Miconazole is a CYP450 inhibitor - warfarin builds up and INR increases
What drugs does acute ingestion of alcohol affect?
Warfarin
Metronidazole
What interaction between amfetamines and SSRIs?
serotonin syndrome
Why can’t you give GTN spray with sildenafil?
Hypotension/MI as a result of the pharmacodynamic interactions of both
What foods are warfarin takers advised to avoid?
leafy greens with high vitamin K
Give a drug-food interaction for ACEi
Patients who have swapped normal salt for Lo-Salt are at risk of hyperkalaemia if they take ACEi or spironolactone/amiloride (another K-sparing diuretic)
What food should be avoided with CCBs such as felodipine?
grapefruit juice - inhibit CYP450, increase the bioavailabiluty of felodipine - increase side effects such as flushing/oedema/collapse
What does grapefruit juice interact with?
CCB
statins
immunosuppressants
anti-arrhythmics
What medications can lithium interact with to cause lithium toxicity?
ACEi prevent the renal clearance of lithium causing lithium toxicity
Can you take rifampicin with COCP?
rifampicin is inducer - reduces the bioavailability of COCP
What happens if you take BB with CCB?
additive effect - hypotension, bradycardia, asystole
give an example of an interaction between BB and CCB?
timolol eye drops and oral verapamil
what happens if both warfarin and nsaid?
GI bleed
What is the interaction between warfarin and some macrolides such as erythromycin/clarithromycin?
macrolide inhibits enzyme. this increases bioavailability of warfarin and thus the INR
What is the interaction between carbamazepine and emergency contraceptives?
carbamazepine is an inducer and reduces the efficacy.
dose of emergency contraceptive should be doubled
What is the interaction between glucosamine and warfarin?
INR increases
how does st johns wort interact with SSRIs
increases the risk of Serotonin syndrome
how does st johns wort interact with MAOIs
hypertensive crisis
how does st johns wort interact with contraceptive
reduces contraceptive cover
What electrolyte abnormality is seen in vit D toxicity?
hypercalcaemia confusion dehydration muscle weakness vomiting stones bones moans groans
what is the effect of hyponatraemia on lithium toxicity?
increases lithium toxicity
What drugs to stop before surgery?
I LACK OP
Insulin
Lithium
Anticoagulants/Antiplatelets
COCP/HRT
K-sparing diuretics
Oral hypoglycaemics
Perindopril (all ACEi)
What are the enzyme inducers?
PC BRAS
Phenytoin Carbamazepine Barbiturates Rifampicin Alcohol (chronic excess) Sulfonylureas
What are the enzyme inhibitors?
AO DEVICES
Allopurinol
Omeprazole
Disulfiram Ethanol (acute consumption) Valproate Isoniazid Ciprofloxacin Erythromycin Sulfonamides
What is the effect of bendroflumethiazide on potassium levels
bendroflumethiazide causes hypokalaemia
loop and thiazide diuretics cause hypokalaemia
what is the effect of ACEi on potassium levels?
ACEi cause hyperkalaemia
what route to give insulin
SC
IV only if sliding scale actrapid
what medication should you stop if hyperkalaemia?
ACEi
what electrolyte abnormality with carbamazepine
hyponatraemia - seizures
what are side effects of diltiazem
oedema
they worsen fluid retention
what treatment for STEMI
MONAT
Morphine (5-10mg) Oxygen only if desaturing Nitrates (GTN 2 puffs sublingual) Aspirin 300mg Ticagrelor 180mg /clopidogrel 300mg
what should you give if stemi pt undergoing PCI
Prasugrel
what treatment if no PCI in stemi patient?
fondaparinux
what treatment for nstemi/unstable angina
MONAT
Morphine 5-10g Oxygen if indicated Nitrates (2 puffs sublingual GTN) Aspirin 300mg Ticagrelor 180 or clopidogrel 300mg
what long term treatment for ACS
CRABS
Clopidogrel 75mg Ramipril Aspirin Beta blocker Statin
what treatment for chronic heart failure
ACEi - ARB if intolerated
Beta blocker - bisoprolol
in heart failure, if ARB and ACEi not tolerated, what to prescribe
hydralazine and nitrate
if symptoms of chronic HF continue despite treatment with ACEi and BB, what to prescribe
spironolactone/amiloride
how to treat ACUTE heart failure
UNLOAD FAST - diuretics
Upright position Nitrates Loop diuretic Oxygen ACEi Digoxin
Fluids (decrease)
Afterload (decrease)
Sodium restrict
how to treat angina
GTN
BB
CCB if no BB (verapamil/diltiazem)
how to treat angina if CCB+BB combo not enough
ivabradine
what secondary prevention for stable angina
statin
aspirin
ACEi if patient has diabetes
describe treatment pathway for HTN if under 55
- A
- A + C or A+D
- A + C + D
describe treatment pathway for HTN if diabetic of any age
- A
- A + C or A+D
- A + C + D
describe treatment pathway for >55 or afro-caribbean
- C
- C + A or C + D
- A + C + D
If patient still hypertensive after triple treatment, what to give if low potassium
k-sparing diuretic if less than 4.5mmol
if patient still hypertensive after triple treatment with HIGH potassium, what to give
alpha or beta blocker
how to treat AF - rate control
Beta blocker or rate limiting CCB (verapamil or diltiazem)
if AF rate not controlled with one drug, what to give
two of three:
- beta blocker
- diltiazem
- digoxin
when to start rhythm control in AF
if less than 48 hours, can start with amiodarone or flecainide
if more than 48 hours, anticoagulate first
what investigations needed before amiodarone
CXR - amiodarone can cause interstitial lung disease
TFT
LFT
U&E
what anticoagulant for AF
warfarin
DOAC - apixaban, rivaroxiban, dabigatran
supraventricular tachy - immediate treatment
IV adenosine 6mg bolus
SVT treatment in asthmatic
no adenosine, use verapamil instead
treatment for ventricular tachy
amiodarone via central line
lidocaine
procainamide
treatment for pericarditis
nsaid and colchicine
treatment for anaphylaxis in adult
IM adrenaline 500mcg
then oral cetirizine or IV chlorphenamine
treatment for anaphylaxis in child 6-12
IM adrenaline 300mcg
treatment for anaphylaxis in 6m-6y
IM adrenaline 150mcg
treatment for patent ductus arteriosus to close the duct
indomethacin or ibuprofen
treatment to keep PDA duct open
prostaglandin E1
