drug interaction
DESCRIPTION
first drug interaction section 2013TRANSCRIPT
Types of drug interaction
Drug Disease
food
pollutant
packaging
Pharmaceutical incompatibility
Drug
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Drug-Drug interaction
Definition: The interaction that
Modifies the effect of one drug (object drug) by prior or concomitant administration of another drug (precipitant drug).
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Precipitant drug: The drug that causes the altered effect
of the object drug
Object drug: The drug that its action is altered by the
precipitant drug
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Discuss a drug interaction
1. Indication of both drugs 2. Mechanism (HOW?) 3. Results/ outcome 4. Evaluation 5. Management & recommendation
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Mechanisms of drug interaction
Pharmacodynamic (PD)
•Affects drug action directly
Pharmacokinetic (PK)
•Affects plasma conc. with time (ADME)
Retrospective VS prospective
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Examples
• Additive: 1- Warfarin+ Aspirin(75 mg daily) Additive anticoagulant effect (Effect) 2- Atropin+ T.C.A. Additive anticholinergic side effect
(Toxicity)
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Examples (cont.)
• Antagonism 1- CNS depressant+ CNS stimulant (Effect) 2- Gallamine + neostigmine NMRB (Ms relaxant) AchEIs(Ms contraction) (Effect)
3- Digoxin + potassium (K+) (Antagonizes digoxin toxicity)
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Group excercise
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Group exercise
Illustrate the mechanism of drug interaction if present.
A- isoprotrenol + propranolol B- Benzodiazepine+ Antihistamine C- Alcohol+ barbiturates D- Aminoglycosides+ cephalosporines E- Gentamycine+ Ethacrynic acid F- Warfarine + vitamine K
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