P450

Background

Coumadin

Antimicrobials

Avoid / P450 Inhibitors

• Quinolones, especially levofloxacin
• Macrolides, especially erythromycin
• Bactrim and sulfonamides
• Flagyl
• Nafcillin, oxacillin

Use

• Azithromycin
• Gentamicin
• Cephalosporin, aminopenicillins
• Nitrofurantoin
• Clindamycin
• Vancomycin

Significant P450 Inhibitors in General

• Grapefruit juice
• Valproate
• INH
• Protease inhibitors (-navir, i.e. ritonavir)
• SSRIs, except escitalopram
• Amiodarone
• Fluoroquinolones
• Sulfonamides
• Macrolides
• Cimetidine
• Omeprazole
• Ketoconazole
• Acute EtOH

Significant P450 Inducers in General

• Phenytoin
• Carbamazepine
• Ethosuximide
• Quinidine/quinine
• Rifampin
• Griseofulvin
• Glucocorticoids
• Barbituates
• St. John's wort
• Chronic EtOH
• Tobacco smoking