Pharmacology Flashcards
Drugs causing lung fibrosis?
- Amiodarone
- Anti-rheumatoid = Methotrexate, sulfasalazine
- Cytotoxic = busulphan, bleomycin
- Ergot-derived dopamine receptor agonists = bromocriptine, cabergoline, pergolide
- Nitrofurantoin
Most common feature of CO poisoning?
Headache
Features of CO toxicity?
- Headache
- N&V
- Vertigo
- Confusion
- Subjective weakness
- Severe toxicity = pink skin and toxicity, hyperpyrexia, arrhythmias, extrapyramidal features, coma, death
Typical carboxyhaemoglobin level?
- <3% non-smokers
- <10% smokers
- 10-30% symptomatic = headache, vomiting
- > 30% severe toxicity
CO poisoning Rx?
- 100% high flow O2 via non-rebreather mask (min 6h, target SpO2 100%, Rx until all symptoms resolved)
- Hyperbaric oxygen (if LOC at any point, neurological signs, myocardial ischaemia/arrhythmia, pregnancy)
TB drugs?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
Rifampicin mushkies?
- MOA = inhibits bacterial DNA dependent RNA polymerase, preventing transcription of DNA into mRNA
- Potent liver enzyme inducer
- Hepatitis, orange secretions
- Flu-like symptoms
Isoniazid mushkies?
- MOA = inhibits mycolic acid synthesis
- Peripheral neuropathy = prevent with pyridoxine (Vitamin B6)
- Hepatitis, agranulocytosis
- Liver enzyme inducer
Pyrazinamide mushkies?
- MOA = converted by pyrazinamidase into pyrazinoic acid which in turn inhibits fatty acid synthase (FAS) I
- Hyperuricaemia causing gout
- Arthralgia, myalgia
- Hepatitis
Ethambutol mushkies?
- MOA = inhibits the enzyme arabinosyl transferase which polymerizes arabinose into arabinan
- Optic neuritis = check visual acuity before and during treatment
- Dose needs adjusting in patients with renal impairment
Metformin MOA?
- Activation of AMP-activated protein kinase
- Increases insulin sensitivity
- Decreases hepatic gluconeogenesis
- May reduce gastrointestinal absorption of carbohydrates
Metformin s/e?
- GI upset intolerable in 20% (nausea, anorexia, diarrhoea)
- Reduced Vitamin B12 absorption (rarely a clinical problem)
- Lactic acidosis with severe liver disease or renal failure
Metformin contraindications?
- CKD eGFR <30 or Cr > 150
- Lactic acidosis during period where there is tissue hypoxia
- Iodine-containing X-ray contrast media (discontinue metformin on day of procedure and 48h after)
- Alcohol abuse is a relative contraindication
Starting metformin mushkies?
- Titrated up slowly to reduce incidence of GI side effects
- If pts develop unacceptable s/e then modified-release metformin should be considered
Verapamil mushkies?
- Angina, hypertension, arrhythmias
- Highly negatively inotropic
- Should not be given with beta blocker as may cause heart block
- S/e = HF, constipation, hypotension, bradycardia, flushing
Diltiazem mushkies?
- Angina, hypertension
- Less negatively inotropic than verapamil but caution should still be exercised when patients have heart failure or are taking beta-blockers
- S/e = hypotension, bradycardia, HF, ankle swelling
Nifedipine, amlodipine, felodipine mushkies
- Dihydropyridines
- Hypertension, angina, Raynaud’s
- Affects the peripheral vascular smooth muscle more than the myocardium and therefore do not result in worsening of HF but may therefore may cause ankle swelling
- Flushing, headache, ankle swelling
Amiodarone s/e?
- Thyroid (hyper and hypo)
- Lung fibrosis
- Liver fibrosis
- Corneal deposits
- Peripheral neuropathy/myopathy
- Photosensitivity
- Slate-grey appearance
- Thrombophlebitis and injection site reactions
- Bradycardia
- Lengthens QTi
Important amiodarone interactions?
- Decreased metabolism of warfarin, therefore increased INR
- Increased Digoxin levels
Statin monitoring?
LFTS at baseline, 3m, 12m
ACEi monitoring?
U&E prior to treatment, after increasing dose, annually
Amiodarone monitoring?
- TFT, LFT U&E, CXR prior
- TFT, LFT every 6m
Methotrexate monitoring?
FBC, U&E, LFTs = before starting, weekly until therapy established, then every 2-3 months
Azathioprine monitoring?
- FBC and LFT before
- FBC weekly for first 4w
- FBC, LFT every 3m