some question of drug interaction

can someone telll me the interaction of the following!
pencillin and procaine
penicillin V table and probenicid
multivitamins containing minerals like Ca, Fe ions with tetacyclines
yasmin contraceptive with amoxicillin
Grape fruit with Nifedipine and phenytoin
verdanafil with erythromycin

Nice to meet you

first, sorry for my poor English

answer：

1：none

2：none

3：2nd grade of interaction

tetracyclines will form to insoluble chelates with many kinds of cations

4：4th grade

amoxicillin may interrupt enterohepatic circulation of oral contraceptivea,

and increase the rate of pregnancy

5：2nd grade

furanocoumarins of grapefruit juice may block CYP3A4 to inhibit the metabolism

of calcium chennel blockers, then the blood concerntration will increase and cause

hypotension.

and no drug-food interaction between phenytoin and grapefruit juice

6:none

[ 本帖最後由 MuteSun 於 2006-6-15 12:48 PM 編輯 ]