Corrections 2 Flashcards
How often should digoxin levels be monitored?
Digoxin level is not monitored routinely, except in suspected toxicity.
Management of hypomagnesaemia?
If <0.4, or tetany, arrhythmias, or seizures–> IV magnesium sulphate
If >0.4 –> oral magnesium salts
What is a key side effect of oral magnesium salts?
Diarrhoea
Features of hypomagnesaemia?
Features may be similar to hypocalcaemia:
- paraesthesia
- tetany
- seizures
- arrhythmias
- decreased PTH secretion → hypocalcaemia
- ECG features similar to those of hypokalaemia
- exacerbates digoxin toxicity
What is a key feature on an ECG in TCA overdose?
QRS widening, due to sodium channel blockade.
This can be associated with ventricular arrhythmias and cardiac arrest.
What is Ethylene glycol?
Ethylene glycol is a type of alcohol used as a coolant or antifreeze
Management for Ethylene glycol toxicity?
fomepizole (this is an inhibitor of alcohol dehydrogenase)
Management of carbon monoxide poisoning?
Hyperbaric oxygen
Which NSAID is associated with a significantly increased risk of cardiovascular events?
Diclofenac
Contraindications of diclofenac?
1) ischaemic heart disease
2) peripheral arterial disease
3) cerebrovascular disease
4) congestive heart failure (New York Heart Association classification II-IV)
In patients with MI secondary to cocaine use, what should they be given as part of acute (ACS) treatment?
IV benzodiazepines
Give 3 drug causes of gingival hyperplasia
1) phenytoin
2) ciclosporin
3) calcium channel blockers (especially nifedipine)
Why should verpamil not be used alongside beta blockers?
As may cause heart block
Which CCB is most negatively inotropic?
Verapamil
Which CCBs result in ankle swelling?
Nifedipine, amlodipine & felodipine
Why can nifedipine result in reflex tachycardia?
Due to peripheral vasodilation
Name the inducers of the P450 system (6)
Carbamazepine
St John’s Wort
Chronic alcohol intake
Rifampicin
Barbiturates: phenobarbitone
Smoking
Name the inhibitors of the P450 system (9)
Erythromycin
Ciprofloxacin
Sodium valproate
Acute alcohol intake
Isoniazid
Amiodarone
Imidazoles: ketoconazole, fluconazole
SSRIs: fluoxetine, sertraline
Allopurinol
Management of heparin-induced thrombocytopenia (HIT)?
Switch to direct thrombin inhibitor e.g. argatroban
Is bleeding more common with LMWH or UH in those with severe renal impairment?
LMWH
Anticoagulant of choice in those with severe renal impairment?
UH
Organophosphates stimulate sympathetic and parasympathetic nervous systems.
However, in clinical practice and in typical scenarios, what presentation predominates?
Overstimulation of the parasympathetic system predominates.
Key features of organophosphate poisoning: DUMBELS
D - defaecation & diaphoresis
U - urinary incontinence
M - miosis (pupil constriction)
B - bradycardia
E - emesis
L - lacrimation
S - salivation
How do organophosphates affect HR?
Bradycardia
What is a key side effect of diclofenac?
Significantly increased risk of cardiovascular events compared with other NSAIDs.
Contraindications for diclofenac?
ischaemic heart disease
peripheral arterial disease
cerebrovascular disease
congestive heart failure
Which NSAIDs have the best cardiovascular risk profiles?
Naproxen & low dose ibuprofen
What is the Yellow Card scheme?
The standard way to report adverse reactions to medications
What should be reported in the Yellow Card scheme?
1) all suspected adverse drug reactions for new medicines (identified by the black triangle symbol)
2) all suspected adverse drug reactions occurring in children, even if a medicine
What is a black triangle drug?
A black triangle indicates that the medication is new to the market, or that an existing medicine is being used for a new reason or by a new route of administration.
What is the most appropriate time to take blood samples for therapeutic monitoring of digoxin levels?
At least 6 hours after last dose
What is the most appropriate time to take blood samples for therapeutic monitoring of phenytoin levels?
Immediately before next dose