Drug - Food Interactions

Drug	Food	Mechanism / Effects / Management
Astemizole	Grapefuit Juice	Inhibition of cytochrome P-450 system; increases bioavailability resulting in high serum levels of this medication. Sedation, apnea, decreased mental alertness, ventricular tachycardia, torsades de pointes. Avoid Grapefuit Juice
Benzodiazepines (diazepam, lorazepam, midazolam, etc)	Grapefuit Juice	Inhibition of cytochrome P-450 system, increases bioavailability resulting in high serum levels of this medication. Ataxia, lethargy, slurred speech, respiratory depression Avoid Grapefuit Juice
Ca Channel Blockers (nifedipine, amlodipine, nicardipine, diltiazem, etc)	Grapefuit Juice	Inhibition of cytochrome P-450 system increases bioavailability and reduces drug disposition, resulting in high serum levels of these medications. Hypotension, dysrhythmias, bradycardia, blockade of SA and AV nodal conduction; dis-association, CNS depression Avoid Grapefuit Juice
Cisapride	Grapefuit Juice	Inhibition of cytochrome P-450 system increases bioavailability and reduces drug disposition, resulting in high serum levels of cisapride, Ventricular tachycardia, torsades de pointes. Avoid Grapefuit Juice Cisapride is no longer a formulary item and may be withdrawn from the US market shortly
Cyclosporine (CSA)	Grapefuit Juice	Inhibition of cytochrome P-450 system and P-Glycoprotein increases bioavailability and reduces drug disposition, resulting in high serum levels of CSA Hypertension, facial flushing, altered taste; feeling of intoxication. Avoid Grapefuit Juice
Disulfiram	Ethanol	Disulfiram inhibits alcohol dehydrogenase; causes severe ethanol intoxication reaction. Flushing, syncope, nausea, vomiting, chest pain, headache, tachycardia, anxiety, confusion. Avoid alcohol
Estramustine	Dairy Products	Calcium-rich foods decrease the absorption of estamustine decreased chemotherapeutic effect. Take 1 hr before or 2 hrs after foods. avoid diary products which on this medication
Fluoroquinolones (like cipro and gatifloxacin)	Dairy Products Tube feedings	Ca++ forms insoluble complex with drug in GI tract leading to a decrease in drug absorption. Subtherapeutic drug levels lead to worsening infections. Hold food or tube feedings for 2 hours before and 2 hours after drug administered. avoid dairy products while on drug
Furazolidone	Tyramine-rich food (cheddar/aged cheeses, herring, Chianti wine, beer, bananas, yeast, avocado, chicken liver, non-fresh beef liver)	Tyramine may cause an abrupt increase in blood pressure and potentially fatal hypertensive crises Flushing. Avoid tyramine-rich food
Isoniazid (INH)	Tyramine-rich food Vit B6	Tyramine may cause an abrupt increase in blood pressure and potentially fatal hypertensive crises NIH promotes an increased excretion of Vit B6; this may result in peripheral neuropathy. Flushing. Minimize tryamine in diet. Separate INH and vitamine administration times.
Linezolid (Zyvox®)	Tyramine-rich food	Linezolid is a reversible, nonselective inhibitor of monoamine oxidase. Therefore, linezolid has the potential for interaction with adrenergic and serotonergic agents, as well as with tyramine. However, no food-linezolid interaction has been reported so far . Tyramine may cause an abrupt increase in blood pressure and potentially fatal hypertensive crises Minimize tryamine in diet.
Metronidazole	Ethanol	Metronidazole inhibits alcohol dehydrogenase; causes severe alcohol intoxication reaction. Flushing, syncope, nausea, vomiting,chest pain, headache, tachycardia, anxiety, confusion. Avoid alcohol
MAO inhibitors [e.g., phenelzine (Nardil), tranylcypromine (Parnate), and linezolid (Zyvox)]	Tyramine-rich food (cheddar / aged cheeses, herring, Chianti wine, beer, bananas, yeast, avocado, chicken liver, non-fresh beef liver)	Tyramine may cause an abrupt increase in blood pressure and potentially fatal hypertensive crises Flushing Linezolid is a reversible, non-specific inhibitor of MAOA. Avoid tyramine-rich food
Mycophenolate (MMF) (Cellcept)	Calcium and Mg Supplements	Ca++ or Mg++ and other multivalent cations form insoluble complex with drug in GI tract leading to a decrease in drug absorption. Subtherapeutic drug levels lead to reduced immunosuppression and increased risk of graft rejection. Separate administration times by at least 2 hours
Phenytoin	Tube feedings	Phenytoin-Ca++ or phenytoin-protein complexes form which reduces GI absorption of phenytoin Concommitant administration with tube feedings will result in decreased drugserum levels; poor therapeutic response to phenytoin. Hold tube feedings 2 hours before and 2 hours after drug given
Procarbazine (Matulane)	Tyramine-rich food (cheddar/aged cheeses, herring, Chianti wine, beer, bananas, yeast, avocado, chicken liver, non-fresh beef liver)	Procarbazine is an alkylating, antineoplastic agent that has some MAO inhibitory action. Tyramine may cause an abrupt increase in blood pressure and potentially fatal hypertensive crises Flushing Avoid tyramine-rich food
Tacrolimus	Grapefuit Juice	Inhibition of cytochrome P-450 system and P-Glycoprotein; increases bioavailability and raises tacro level Increased side effects associated with elevated tacro (hypertension, nephrotoxicity, headache, etc). Over-immunosuppression, infections, increased risk for PTLD and PTDM. Avoid Grapefuit Juice
Tetracyclines (e.g., doxycycline, monocycline, etc)	Dairy Products	Ca++ forms insoluble complex with drug in GI tract leading to a decrease in drug absorption Subtherapeutic drug levels decrease antimicrobial efficacy. Avoid dairy products while on drug
Warfarin	Food rich in vitamin K (green leafy vegetables; see coumadin teaching booklet for addtional information)	Vitamin K antagonizes warfarin's ability to reduce vitamin K-dependent coagulation factors Interference with the therapeutic effect of warfarin. Maintain a consistent diet, which should not contain excessive amounts of vitamin K rich food Avoid: kale, parsley, and green teas (see coumadin teaching booklet for more information)