Medication Interactions Flashcards
Ca, Fe, Antacids and dairy all reduce absorption of ______.
tetracycline. An antibiotic.
True/False: Only unbounded drug interacts with receptors.
True. Protein-bound molecules are not available to exert pharmacological effect.
What drug displaces MTX, leaving it unbound?
Aspirin.
Furosemide displaces _______.
warfarin.
T3 and T4 has a (strong OR weak) affinity with plasma protein.
Strong.
How does the dosing of T4 need to change for the elderly or those with hepatic/renal disease?
The dose needs to decrease. As their is less capacity to produce plasma protein so there is more unbound drug in the system.
How does Aspirin effect the excretion of MTX or penicillin?
It occupies the transporter so the drugs cannot be transported to the renal tubules for excretion.
What are some ADRs for MTX?
Alopecia, GI damage, myelosuppression.
What food majorly affects the bioavailability of certain drugs?
Grapefruit.
P450
Liver enzyme that metabolised medications.
Grapefruit contains _______ ______ which _______ P450.
flavonoid naringin, INHIBITS
When CYP450 is inhibited the amount of the drug in the system _____.
Increases.
What are some examples of drugs that grapefruit interacts with?
Oestrogen, warfarin, nifedipine, verapamil.
What effect does St John’s Wort have on metabolism?
It increases the metabolism of certain drugs by inducing CYP450.
What are some examples of drugs that inhibit CYP450?
Cimetidine, omeprazole, metronidazole, Macroglides, tetracycline,…
