Physiochemical Properties Lecture Flashcards
Define drug-drug interactions
One substance can affect the metabolism of another
- Why medicines have warnings on them
What % does metabolism account for in drug clearance?
75% and 75% of that is metabolized by CYP450
CYPs interact with?
Mostly drugs with low %F and high first pass metabolism
Define terfenadine
Antihistamine drug on the market for hayfever
- Causes life threatening cardiac arrhythmias when co-administered with medicines like erthromycin and ketoconazole (antifungal)
- — inhibits hepatic P450 enzymes
Grapefruit juice does what?
Inhibits CYP 3A4 P450 in the small intestine –> toxic side effects
Define zwitterion
molecule contains both a positive and negative charge
Terfendine can be oxidized to?
Fexofenadine which decreases hERG
- doesn’t cause cardiac arrhythmias
- Ionic, water soluble doesn’t hit hERG
With warfarin you don’t eat?
Vitamine K foods (chickpeas, spinach, parsley)
With Lanoxin you don’t eat?
Black Licorice –> increases toxicity, and reduces effectiveness in BP meds
What is MAOI’s?
Monoamine oxidase inhibitors
Antidepressants
– Decreased noradrenaline, serotonin and dopamine and MAOI’s increase these levels by reducing oxidation of amines
- Can have cardiovascular side effects
Cheese, wine, beer does what?
(foods with high levels of tyramine)
- Causes release of noradrenaline which are normally metabolized by MAOs but those have been inhibited so the levels rise
- NA is a vasoconstrictor so BP rise uncontrollably –> cardiovascular event
Define idiosyncratic toxicity
Other toxic effects we don’t understand
- Increased potency reduces this
- Have two or more compounds in development
