Pharmacology Interactions and ADRs Flashcards
Digoxin toxicity
Narrow QRS, PR interval prolongation, VT, VF
NSAID side effects
Renal failure (-> Heart failure)Reduced prostaglandin synthesis, increased gastric acid production, reduced bicarbonate, reduced mucus,
Antidepressant anticholinergic side effects
Dry moth Dry eyes Dilated pupils and photosensitivity Diplopia Tachycardia
ACEI side effects
Cough
Hyperkalaemia
Hypotension
Renal failure (if with a diuretic and NSAID)
Dose dependent hepatotoxicity
Paracetamol
Aspirin
Dose independent hepatotoxicity
Isoniazid Pyrazinamide Valproate Methyldopa NSAID Phenytoin Statin
Dose dependent cholestatic drugs
Rifampicin
Oestrogens
Dose independent cholestatic drugs
Chlorpromazine Clavulanic acid (Co-amox) Cloxacillin (Fluclox) Clarithromycin Chlorpropamide Carbimazole Cimetidine
Micro vesicular fat deposition (Reye’s syndrome)
Valproate
Aspirin
Tetracyclines
Macro vesicular fat and cirrhosis
Alcohol
Amiodarone
Methotrexate
Rapid ADR
IV vancomycin can cause Red Man syndrome
1st Dose ADR
Type I hypersensitivity e.g. Penicillin allergy
Intermediate response ADR
Carbimazole or 5-ASAs can cause agranulocytosis after 3 months
Monitor for sore throat
Intermediate response ADR
Carbimazole or 5-ASAs can cause agranulocytosis after 3 months
Monitor for sore throat
Late response ADR
Corticosteroid and OP
Dopamine receptor antagonist and tardive dyskinesia
Delayed ADR
Cancer e.g. on Ciclosporin
Dose toxicity
Digoxin
Phenytoin
Theophylline
Modified release lithium
Concentration toxicity
Digoxin toxicity from renal insufficiency
Effect of opiate, TCA and antimuscarinics on GI motility
Reduced GI motility
Effect of metoclopramide on GI motility
Increased GI motility (Dopamine receptor antagonist)
Effect of cholestyramine on absorption of digoxin and warfarin
Reduced GI absorption of digoxin and warfarin
Effect of Antacids and milk on absorption of tetracyclines
Chelation of tetracycline reduces GI absorption
Effect of iron on prednisolone GI absorption
Chelation of prednisolone reduces GI absorption
Effects of antibiotics on warfarin absorption
Reduced Vit K synthesis potentiates warfarin
Effect of coeliac disease on digoxin absorption
Decreased GI absorption of digoxin
Effect of coeliac disease on propranolol absorption
Increased GI absorption of propanolol
Effect of coeliac disease on propranolol absorption
Increased GI absorption of propanolol
Interaction of valproate and phenytoin
Displacement of phenytoin from plasma protein, inhibiting metabolism
Interaction of ASA/NSAIDs and Methotrexate
Displacement of methotrexate from plasma proteins, reducing its secretion and augmenting its toxicity
Interaction of sulphonamides/Vitamin K/Indometacin on bilirubin
Displacement of bilirubin and reduced excretion in neonates causing kernicterus