Pharmacology - Corrections Flashcards
What is the correct rate of infusion of N-acetylcysteine in a paracetamol overdose?
IV N-acetylcysteine over 1 hour
Acetylcysteine is a common cause of anaphylactic reactions, generally managed with slower infusions (i.e. this rate reduces risk of adverse effects).
What class of drug is doxazocin?
Alpha blocker
Give 2 examples of alpha blockers
1) tamsulosin
2) doxazosin
What medications may precipitate lithium toxicity?
1) diuretics (especially thiazides)
2) ACEi/ARBs
3) NSAIDs
4) metronidazole.
How can NSAIDs predispose to lithium toxicity?
NSAIDs can cause renal impairment by decreasing prostaglandin synthesis –> decreases in glomerular filtration rate. There is evidence that these drugs can increase lithium levels and decrease renal lithium clearance.
What is the appropriate dose of IM adrenaline in anaphylaxis?
0.5mg - 0.5ml 1:1000 IM
Which drugs should be AVOIDED in renal failure?
1) Abx: tetracycline, nitrofurantoin
2) NSAIDs
3) lithium
4) metformin
Which drugs are likely to accumulate in chronic kidney disease so will need dose adjustment?
- most antibiotics including penicillins, cephalosporins, vancomycin, gentamicin, streptomycin
- digoxin, atenolol
- methotrexate
- sulphonylureas
- furosemide
- opioids
Tinnitus is an early symptom of an overdose of what?
Salicylates e.g. aspirin
Who is at risk of lactic acidosis from metformin?
Patients with severe liver or renal failure.
Review dose in patients with eGFR <45 and STOP in <30.
What monitoring investigations are required in patients on amiodarone?
TFTs & LFTs every 6 months
CXR prior to starting treatment (but not routinely)
What is G6PD deficiency?
An X-linked recessive disorder that causes a defect in the red cell enzyme glucose-6-phosphate dehydrogenase.
This deficiency leads to intravascular haemolysis which can be triggered by the ingestion of certain drugs and foods (including fava (broad) beans).
What drugs are contraindicated in G6PD deficiency?
Drugs that can precipitate haemolysis:
- antimalarials
- ciprofloxaciin
- sulphonamides (including co-trimoxazole)
- sulphonylureas
- sulphasalazine
What are quinolones?
Give 2 examples
A group of Abx that work by inhibiting DNA synthesis and are bactericidal in nature.
- ciprofloxacin
- levofloxacin
Adverse effects of quinolones?
- lower seizure threshold in patients with epilepsy
- tendon damage (including rupture) - the risk is increased in patients also taking steroids
- cartilage damage has been demonstrated in animal models and for this reason quinolones are generally avoided (but not necessarily contraindicated) in children
- lengthens QT interval
What are the 4 key drugs used in the management of TB?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
What are the most common side effects of rifampicin?
- orange bodily fluids
- rash
- hepatotoxicity
- enzyme inducer (drug interactions)
- flu like symptoms
What are the most common side effects of Isoniazid?
- peripheral neuropathy
- psychosis
- hepatotoxicity
- agranulocytosis
How can peripheral neuropathy as a result of isoniazid be prevented?
With pyridoxine (vitamin B6)
What are the most common side effects of pyrazinamide?
- arthralgia & myalgia
- gout (due to hyperuricaemia)
- hepatotoxicity
- nausea
What are the most common side effects of ethambutol?
- optic neuritis (check visual acuity before and during treatment)
- rash
If women take HRT for premature menopause, how long should it be continued for?
Until age of 50
Define premature menopause
Ovarian failure occurring before the age of 40.
What is the most important reason in giving HRT to women with premature menopause?
Preventing development of osteoporosis