Adverse effects of drugs Flashcards
What are two reasons why side effects occur?
The drugs hits it’s target but that target is in sites (other than where is it required) eg B-adrenoceptor agonists/antagonists
The drug is off target - poor selectivity or metabolised (eg Terfenadine and grapefruit juice)
What drugs/patient characteristics increase the likelihood of overdoses reactions occurring?
When the drug has a low therapeutic winow
When the patient has an underlying, abnormalitly in metabolism/excretion
When there is drug-drug interaction
What is the effect of dexamethasone on cytochrome P450?
Stimulates it
Is what a drug will do to the body pharmacokinetics or pharmacodynamics?
Pharmacodynamics
Why does liver damage occur with high doses of paracetamol?
Because production of its toxic metabolite NADQI out stretches the ability of glutathione to handle it
What are the four type of adverse drug effects?
Side effects
Overdose effects
Idiosyncratic effects
Hypersensitivity reactions
Is what will happen to a drug in the body pharmacokinetics or pharmacodynamics?
Pharmacokinetics
Can you get hypersensitivity responses after the first dose of a drug?
Yes
What is the main difference between side effects and overdose effects?
Side effects occur at a therapeutic dose while overdose effects occur when too much drug accumulates in plasma
What is an example of an idiosyncratic effect?
10% of people are unable to metabolise codeine into morphine due to abnormal CYP2D6
Why must you be careful when taking erythromycin with other drugs?
Erythromycin inhibits P450
Is liver damage or gastric bleeding a side effect of paracetamol?
Liver damage, gastric bleeding is aspirin
Are idiosyncratic side effects dose dependent?
Yes
Why do some people get idiosyncratic side effects?
Genetically predisposed
What is the side effect of aspirin in the stomach?
Gastric bleeding due to inhibition of prostaglandin production
