DRUG INTERACTIONS

Column 1	Column 2
acetazolamide	aspirin^1E
allopurinol	azathioprine^2E captopril^E enalapril^E mercaptopurine^2E
aminophylline	carbamazepine^3B ciprofloxacin^1B clarithromycin^1B erythromycin^1Blithium^4Cmexiletine^1Bphenobarbital^3Bphenytoin^3,4B primidone^3B propranolol^1B rifampin^3Britonavir^3Bzileuton
amiodarone	digoxin^2C,D fosphenytoin^2,3B phenytoin^2,3B procainamide^2B quinidine^2,3B warfarin^2B
amitriptyline	phenelzine^E selegiline^E tranylcypromine^E
amobarbital	warfarin^4B
aspirin	acetazolamide^2E methotrexate^2A,C
astemizole*	clarithromycin^1B,E erythromycin ^1B,E fluconazole^1B,E ketoconazole^1B,E itraconazole^1B,E nelfinavir^1B
azathioprine	allopurinol^1E captopril^1E
bromocriptine	midrin^E phenylpropanolamine^E
butabarbital	warfarin^4B
butalbital	warfarin^4B
captopril	allopurinol^Eazathioprine^2E mercaptopurine^2E
carvedilol	rifampin^3B
carbamazepine	aminophylline^4B clarithromycin^1Bcyclosporine^4B danazol^1B propoxyphene^1B tacrolimus^4B theophylline^4B topiramate^2B valproic acid^5B verapamil^1B warfarin^4B
chloramphenicol	fosphenytoin^2B phenytoin^2B warfarin^2B
chlorothiazide	lithium^2C
chlorpropamide	ethanol^E
choline salicylate	methotrexate^2A,C
ciprofloxacin	aminophylline^2B theophylline^2B
cisapride	clarithromycin^1B,E erythromycin^1B,E fluconazole^1B,E indinavir^1B itraconazole^1B,E ketoconazole^1B,E ritonavir^1B
cisplatin	ethacrynic acid^E
clarithromycin	aminophylline^2B astemizole ^2B,Ecarbamazepine^2B cisapride^2B,E cyclosporine^2B delavirdine^1,2B diazepam^2B disopyramide^2B midazolam ^2Britonavir^1B tacrolimus^2B theophylline^2B warfarin^2B
clomipramine	phenelzine^E selegiline^E tranylcypromine^E
cyclosporine	carbamazepine^3B clarithromycin^1B digoxin^2C diltiazem^1B erythromycin^1B fluconazole^1B fosphenytoin^3B itraconazole^1B ketoconazole^1B pentobarbital^3B phenobarbital^3B phenytoin^3B primidone^3B rifampin^3B verapamil^1B
danazol	carbamazepine^2B warfarin^2F
delavirdine	clarithromycin^1,2B fluoxetine^1Bindinavir^2B ketoconazole^1B rifabutin^1,3B rifampin^3B
desipramine	phenelzine^E ritonavir^1B tranylcypromine^E
dextroamphetamine	phenelzine^E selegiline^E tranylcypromine^E
dextromethorphan	fluoxetine^E paroxetine^E phenelzine^E selegeline^E sertraline^E tranylcypromine^E
diazepam	clarithromycin^1B fluconazole^1B itraconazole^1B ketoconazole^1B
digoxin	amiodarone^1C,D cyclosporine^1C quinidine^1C,D rifampin^3B,D tacrolimus^1C
diltiazem	carbamazepine ^2Bcyclosporine^2B tacrolimus^2B
disopyramide	clarithromycin^1B erythromycin^1B
disulfiram	ethanol^E fosphenytoin^2B,C metronidazole^E phenytoin^2B warfarin^2B
enalapril	allopurinol^E
enoxaparin	ketorolac^E
erythromycin	aminophylline^2B astemizole^{2 B,E} carbamazepine^2B cisapride^2B,E cyclosporine^2B disopyramide^2B indinavir ^1,2Britonavir ^1Btacrolimus^2B theophylline^2B warfarin^2B
estrogens	nelfinavir^3B rifampin^3B ritonavir^3B topiramate^3B troglitazone^3B warfarin ^5B
ethacrynic acid	cisplatin^Egentamicin^E tobramycin^E
ethanol	chlorpropamide^E disulfiram^E methotrexate^B,Emetronidazole^E procarbazine^E tolbutamide^E
etretinate	methotrexate^B,E
felodipine	cabamazepine^3B
fluconazole	astemizole ^2B,Ecisapride^2B,E cyclosporine^2B diazepam^2Bfosphenytoin^2B midazolam^2B phenytoin^2B rifampin ^{3 4B}tacrolimus^2Btriazolam ^2B zidovudine ^1B
fluorouracil	metronidazole^1C
fluoxetine	carbamazepine^2B delavirdine^2B dextromethorphan^E phenelzine^E selegiline^E tranylcypromine^E
fluoxymesterone	warfarin^2F
fosphenytoin	aminophylline^3,4B amiodarone^1,4B chloramphenicol^1B cyclosporine^4B disulfiram^1B,C fluconazole^1B isoniazid^1B rifampin^3B tacrolimus^4B theophylline^3,4B valproic acid^5A,B warfarin^5A,B
ganciclovir	zidovudine^E
gemfibrozil	lovastatin^E simvastatin^E warfarin^2F
gentamicin	ethacrynic acid^E
heparin	ketorolac^E
hydrochlorothiazide	lithium^2C
imipramine	phenelzine^E selegiline^E tranylcypromine^E
indinavir	cisapride^2B clarithromycin^1,2B delavirdine^1B erythromycin^1,2Bketoconazole^1B rifabutin ^2,3B rifampin^2,3B
isoniazid	carbamazepine^2B fosphenytoin^2B phenytoin^2B
itraconazole	astemizole ^2B,Ecisapride^2B,E cyclosporine^2B diazepam^2Bfosphenytoin^3B lovastatin^2B midazolam ^2Bphenytoin^3B rifampin^3,4B simvastatin^2B tacrolimus^2B triazolam^2B
ketoconazole	astemizole ^2B,Ecisapride^2B,E cyclosporine^2B delavirdine^2B diazepam^2Bindinavir^2B midazolam^2B rifampin^3,4Btacrolimus^2Btriazolam^2B
ketorolac	enoxaparin^E heparin^E warfarin^E
lithium	aminophylline^3C carbamazepine^1F chlorothiazide^1C hydrochlorothiazide^1C phenelzine^E theophylline^3C thiazide diuretics^1C tranylcypromine^E
lovastatin	gemfibazil^E itraconazole^1B warfarin^2F
meperidine	phenelzine^E selegiline^E tranylcypromine^E
mercaptopurine	allopurinol^1E captopril^1E
mesna	warfarin^2F
methotrexate	aspirin^1A,C choline salicylate^1A,C ethanol^B,Eetretinate^B,ENSAIDs^1A,C probenecid^1C salicylates^1A,C trimethoprim/sulfamethoxazole ^1A,C
methylphenidate	phenelzine^E selegiline^E tranylcypromine^E
methyltestosterone	warfarin^2F
metronidazole	disulfiram^E ethanol^E fluorouracil^2Cwarfarin^2B
mexiletine	aminophylline^2B theophylline^2B
midazolam	clarithromycin^1B fluconazole^1B itraconazole^1B ketoconazole^1B
midrin	bromocriptine^E
mitomycin	vinblastine^E
nandrolone	warfarin^2F
nefazodone	phenelzine^E selegiline^E tranylcypromine^E
nelfinavir	astemizole^2B estrogens^4B oral contraceptives^4B rifabutin^2,3Brifampin^3B
NSAIDs	methotrexate^2A,C
oral contraceptives	nelfinavir^3B rifampin^3B ritonavir^3B topiramate^3B warfarin ^5B
paroxetine	dextromethorphan^E phenelzine^E selegiline^E tranylcypromine^E
pentobarbital	aminophylline^4B cyclosporine^4B tacrolimus^4B theophylline^4B valproic acid^1B warfarin^4B
phenelzine	amitriptyline^E clomipramine^E desipramine^E dextroamphetamine^Edextromethorphan^Efluoxetine^E imipramine^E lithium^E meperidine^E methylphenidate^E nefazodone^E paroxetine^E pseudoephedrine^E sertraline^E sumatriptan^E tramadol*^E
phenobarbital	aminophylline^4B cyclosporine^4B tacrolimus^4B theophylline^4B valproic acid^1B warfarin^4B
phenylpropanolamine	bromocriptine^E
phenytoin	aminophylline^3,4B amiodarone^1,4B chloramphenicol^1B cyclosporine^4B disulfiram^1B,C fluconazole^1B isoniazid^1B itraconazole^4B rifampin^3B tacrolimus^4B theophylline^3,4B valproic acid^5A,B warfarin^5A,B
potassium	spironolactone^1C triamterene^1C
primidone	aminophylline^4B cyclosporine^4B tacrolimus^4B theophylline^4B valproic acid^1B warfarin^4B
probenecid	methotrexate^2C zidovudine^2C
procainamide	amiodarone^1B
procarbazine	ethanol^E
propoxyphene	carbamazepine^2B
propranolol	aminophylline^2B theophylline^2B
pseudoephedrine	phenelzine^E tranylcypromine^E
quinidine	amiodarone^1B digoxin^2C,D rifampin^3B
rifabutin	delavirdine^1,4Bindinavir^1,4B nelfinavir^1,4B ritonavir^1,4B saquinavir^4B
rifampin	aminophylline^4B carvedilol^4Bcyclosporine^4B delavirdine^4B digoxin^4B,D estrogens^4B fluconazole^3,4B fosphenytoin^4B ^4B itraconazole^3,4B ketoconazole^3,4B nelfinavir^4B oral contraceptives^4B phenytoin^4B quinidine^4B ritonavir^4B saquinavir^4B tacrolimus^4B theophylline^4B warfarin^4B zidovudine^4B
ritonavir	aminophylline^4B cisapride^2B clarithromycin^2B desipramine^2B erythromycin ^2B estrogen^4B oral contraceptives^4B rifabutin^2,3B rifampin^3B theophylline^4B
salicylates	methotrexate^2C
saquinavir	rifabutin^3Brifampin^3B
selegiline	clomipramine^E dextroamphetamine^E dextromethorphan^E fluoxetine^E imipramine^E methylphenidate^E meperidine^E nefazodone^E paroxetine^E sertraline^E
sertraline	dextromethorphan^E phenelzine^E selegiline^E tranylcypromine^E
simvastatin	gemfibrazil^E itraconazole^1B warfarin ^2F
spironolactone	potassium^2C
sumatriptan	phenelzine^E tranylcypromine^E
tacrolimus	carbamazepine^3B clarithromycin^1Bdigoxin^2C diltiazem^1B erythromycin^1Bfluconazole^1B fosphenytoin^3Bitraconazole^1Bketoconazole^1B pentobarbital^3B phenobarbital^3B phenytoin^3B primidone^3B rifampin^3B verapamil^1B
testosterone	warfarin^2F
theophylline	carbamazepine^3B ciprofloxacin^1B clarithromycin^1B erythromycin^1B fosphenytoin^3,4B lithium^4C mexiletine^1Bpentobarbital^3B phenobarbital^3B phenytoin^3,4B primidone^3B propranolol^1B rifampin^3B ritonavir^3Bzileuton^1B
thiazide diuretics	lithium^2C
tobramycin	ethacrynic acid^E
tolbutamide	ethanol^E
topiramate	carbamazepine^1B estrogen^4Boral contraceptives^4B
tranylcypromine	amitriptyline^E clomipramine^E desipramine^E dextroamphetamine^Edextromethorphan^Efluoxetine^E imipramine^E lithium^E meperidine^E methylphenidate^E nefazodone^E paroxetine^E pseudoephedrine^E sertraline^E sumatriptan^E tramadol*^E
triamterene	potassium^2C
triazolam	fluconazole^1B itraconazole^1Bketoconazole^1B
trimethoprim-sulfamethoxazole	methotrexate^2AC warfarin ^2B
troglitazone	estrogens^4B
valproic acid	carbamazepine^5Bfosphenytoin^5A,B pentobarbital^2B phenobarbital^2B phenytoin^5AB primidone^2B zidovudine^2B
verapamil	carbamazepine^2B cyclosporine^2B tacrolimus^2B
vinblastine	mitomycin^E
warfarin	amiodarone^1B amobarbital^3B butabarbital^3B butalbital^3B carbamazepine^3B chloramphenicol^1B clarithromycin^1B danazol^1F disulfiram^1B erythromycin^1B estrogens^5B fluoxymesterone^1F fosphenytoin^5A,B gemfibrozil^1F ketorolac^E lovastatin^1F mesna^1F methyltestosterone^1F metronidazole^1B nandrolone^1Foral contraceptives^5B pentobarbital^3B phenobarbital^3B phenytoin^5A,B primidone^3B rifampin^3B simvastatin ^1Ftestosterone^1F trimethoprim-sulfamethoxazole^1B zileuton^1B
zidovudine	ganciclovir^E probenecid^1C rifampin^3B valproic acid^1B
zileuton	aminophylline^2B theophylline^2Bwarfarin^2B

1. Hansten PD, Horn JR. Hansten and Horn’s Drug Interactions Analysis and Management. Applied Therapeutic Inc., Vancouver, WA. 1997.

2. Zuccharo FJ, Hogan MJ. Evaluation of Drug Interactions. First Databank, St. Louis, MO. 1996.

3. Quinn DJ, Day RO. Drug interactions of clinical importance: an updated guide. Drug Safety. 1995; 12 (6): 393-452.

4. Hansten PD, Horn JR. Drug interactions with antiretroviral agents. Drug Interaction Newsletter: A Clinical Perspective and Analysis of Current Developments. Applied

5. The University of Alabama at Birmingham/University Hospital Newsletter. Drug interactions of azole antifungals. Drug Information Bulletin . 1996; 30 (12): 1-4.

6. Package insert information for delavirdine, indinavir, lovastatin, nelfinavir, ritonavir, saquinavir, simvastatin and topiramate.

Prepared by: Carol Bonsignore, Pharm.D., Drug Information Service, Department of Pharmacy, 966-2373. Updated 3/98