Pharmacology Flashcards
What are the features of cocaine toxicity and how is it managed?
MOA:
- Blocks uptake of dopamine, noradrenaline and serotonin
Adverse effects:
CARDIO - coronary artery spasms, htn, QRS/QT prolong, aortic dissection
NEURO - seizures, mydriasis, hyperreflexia, hypertonia
PSYCH - agitation, psychosis, hallucinations
OTHER - ischaemic colitis if ingested, hyperthermia, metabolic acidosis, rhabdo
Management:
1. Chest pain - benzo + GTN
2. Hypertension - benzo + sodium nitroprusside
What are the features of ecstasy poisoning and how is it managed?
Features:
CARDIO - tachycardia, htn
NEURO - agitation, anxiety, ataxia
OTHER - hyponatremia, hyperthermia, rhabdo
Management:
Supportive +/- dantrolene for hyperthermia
What drugs are used in alcohol problem drinking?
Acute withdrawal - chlordiazepoxide
Promoting abstinence - disulfram (reaction when mixed with alcohol)
Reducing craving - acamprosate
How is paracetamol overdose managed?
- Activated charcoal if ingested <1h ago
- Otherwise blood test +/- NAC after 4h
- Commence NAC without bloods if staggered OD
- Commence NAC without bloods if 8-24h
- Liver transplant (if pH<7.3 24h after ingestion or all of PT >100, creat >300, grade III/IV encephalopathy)
NAC is infused over 1h
How does salicylate overdose (aspirin) present and how is it managed?
Features:
- Hyperventilation
- Tinnitus
- Mixed respiratory alkalosis and metabolic acidosis
Management:
- ABC
- Urinary alkalinization with IV bicarbonate
- Haemodialysis
How is benzodiazepine overdose managed?
- Supportive care
- Flumazenil if severe (but risk of seizure)
How is TCA overdose managed?
- IV bicarbonate to reduce the risk of seizureas and arrhythmias
- AVOID NORMAL ANTIARRHYTHMICS
How is lithium toxicity managed?
Presents as coarse tremor, hyperreflexia, confusion, polyuria, seizure, coma
Precipitants:
- Dehydration and renal failure
- Drugs (diuretics esp thiazides, ACEi/ARBs, NSAIDs, metronidazole)
Management:
- Mild to moderate: IV saline
- Consider sodium bicarbonate
- Severe: haemodialysis
How is beta-blocker overdose managed?
- Give atropine if bradycardia
- Give glucagon if refractory
How is ethylene glycol poisoning managed?
- Fomepizole (works by inhibitingalcohol dehydrogenase)
- Haemodialysis if refractory
(ethylene glycol is found in hydraulic brake fluid, solvents, paints)
How is methanol poisoning managed?
- Fomepizole
- Haemodialysis
How does organophosphate insecticide poisoning present and how is it managed?
Features:
SLUD - salivation, lacrimuation, urination, defecation
Hypotension and bradycardia
Miosis and muscle fasciculations
Management:
- Atropine
How does digoxin work and how is toxicity managed?
MOA:
- Cardiac glycoside used in rate control in AF management
- Decreases conduction through the AV node to decrease ventricular rate, and increases cardiac muscle contraction
- No routine monitoring
Toxicity:
- Measure concentrations 8-12 hours after last dose
- Presents as yellow vision, confusion, arrhythmias, gynaecomastia
- Precipitated by hypokalemia
- Manage with DIGIBIND (Digoxin-specific antibody fragments) and correct arrhythmias
How is iron poisoning managed?
- Dexferrioxamine (chelating agent)
How is lead poisoning managed?
- Dimercaprol or calcium edetate
What are the features of carbon monoxide poisoning and how is it managed?
Features:
- Carbon monoxide has high affinity for Hb causing left shift of oxygen dissociation curve and tissue hypoxia
- Presents as headache, N&V, pink mucosa
- >3% carboxyHb or >10% in smokers
Management:
- 100% high flow oxygen ASAP for minimum of 6 hours
- Hyperbaric oxygen
How is cyanide poisoning managed?
- Hydroxycobalamin
- Can also give combination of amyl nitrite, sodium nitrite and sodium thiosulfate
How does amiodarone cause thyroid dysfunction?
- Hypothyroidism
- Due to high iodine content of amiodarone causing an autoregulary effect by inhibiting thyroxine formation - Thyrotoxicosis type 1
- Excess iodine-induced thyroid hormone synthesis with goitre formation
- Manage with carbimazole or potassium perchlorate - Thyrotoxicosis type 2
- Destructive thyroiditis
- Manage with steroids
What are the side effects and contraindications of phosphodiesterase V inhibitors (PDE5)?
eg. sildenafil
Side effects:
- Visual disturbance (blue discolouration), AIN
- Nasal congestion and headache
- Flushing
- GI side effects
Contraindications:
- Pts on nitrates and realted drugs eg. nicoranidl
- Hypotension
- Recent stroke or MI (wait 6 months)
What are the adverse effects and interactions of allopurinol?
Adverse effects:
DERM! (should stop immediately if develop a rash) - SCAR, DRESS, SJS
Interactions:
- Azathioprine; should reduce dose
- Cyclophosphamide; may cause marrow toxicity
- Theophylline; inhibits breakdown
Which drugs cause urinary retention?
- Opiates
- Anticholinergics eg. antipsychotics/antihistamines
- Tricyclic antidepressants
- NSAIDs
- Disopyramide
Which drugs cause lung fibrosis?
- Amiodarone
- RA drugs (methotrexate, sulfasalazine, gold)
- Cytotoxic agents (busulphan, bleomycin)
- Nitrofurantoin
- Dopamine agonists (bromocriptine, cabergoline, pergolide)
How do you manage opiod overdose and dependence?
Overdose:
- Naloxone
Dependence:
- Methadone or buprenorphine
- Monitor compliance with urinalysis
- Should last 4 weeks in IP setting or 12 weeks in the community
