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From: Stephen R. Saklad, Pharm.D.
Date: Mon, 28 Nov 1994 23:05:01 -0600

This almost deserves to be a FAQ. I have copied the Micromedex drug consult on this from the current database.

(c) 1974-1994 Micromedex Inc. - All rights reserved - Vol. 82 Exp. 12/94

Q. Please review the dietary restrictions that should be observed when a patient is receiving monoamine oxidase inhibitor (MAOI) therapy.

A. Tyramine is an amino acid which is found in various foods and is an indirect sympathomimetic that can cause a hypertensive reaction in patients receiving MAOI therapy. Monoamine oxidase is found in the gastrointestinal tract and inactivates tyramine; when drugs prevent the catabolism of exogenous tyramine, this amino acid is absorbed and displaces norepinephrine from sympathetic nerve endings and epinephrine from the adrenal glands. If a sufficient amount of pressor amines are released, a patient may experience a severe occipital or temporal headache, diaphoresis, mydriasis, nuchal rigidity, palpitations, and the elevation of both diastolic and systolic blood pressure may ensue (Anon, 1989; Da Prada et al, 1988; Brown & Bryant, 1988). On rare occasions, cardiac arrhythmias, cardiac failure, and intracerebral hemorrhage have developed in patients receiving MAOI therapy that did not observe dietary restrictions (Brown & Bryant, 1988). Therefore, dietary restrictions are required for patients receiving MAOIs.

Extensive dietary restrictions previously published were collected over a decade ago and due to changes in food processing and more reliable analytical methods, new recommendations have been published (Anon, 1989; McCabe, 1986).

The tyramine content of foods varies greatly due to the differences in processing, fermentation, ripening, degradation, or incidental contamination. Many foods contain small amounts of tyramine and the formation of large quantities of tyramine has been reported if products were aged, fermented, or left to spoil. Because the sequela from tyramine and MAOIs is dose-related, reactions can be minimized without total abstinence from tyramine-containing foods. Approximately 10 to 25 mg of tyramine is required for a severe reaction compared to 6 to 10 mg for a mild reaction. Foods that normally contain low amounts of tyramine may become a risk if unusually large quantities are consumed or if spoilage has occurred (McCabe, 1986).

Three lists were compiled to minimize the strict dietary restrictions that were previously used and improve compliance with and safety of MAOI therapy.  

Foods to Avoid

This list consists of foods with sufficient tyramine (in small or usual serving sizes) to create a dangerous elevation in blood pressure and which therefore should be avoided (McCabe, 1986).


Foods to Use with Caution

This list categorizes foods that have been reported to cause a hypertensive crisis if foods were consumed in large quantities or stored for prolonged periods, or if contamination occurred. Small servings (1/2 cup, or less than 120 mL) of the following foods are not expected to pose a risk for patients on MAOI therapy (McCabe, 1986).


Foods with Insufficient Evidence for Restriction

More than 200 foods contain tyramine in small quantities and have been implicated in reactions with MAOI therapy. However, the majority of the previous reactions were due to the consumption of spoiled food. Evidence does not support the restriction of the following foods listed if the food is fresh (McCabe, 1986).

Any protein food, improperly stored or handled, can form pressor amines through protein breakdown. Chicken and beef liver, liver pate, and game generally contain high amine levels due to frequent mishandling. Game is often allowed to partially decompose as part of its preparation. Ayd (1986) reported that the freshness of the food is a key issue with MAOIs and that as long as foods are purchased from reputable shops and stored properly, the danger of a hypertensive crisis is minimal. Some foods should be avoided, the most dangerous being aged cheeses and yeast products used as food supplements (Gilman et al, 1985).

With appropriate dietary restrictions, the incidence of hypertensive crises has decreased to approximately 4% (Zisook, 1985). Treatment of a hypertensive reactions includes the administration of phentolamine (Anon, 1989) 2.5 to 5 milligrams intravenously (slow) titrated against blood pressure (Zisook, 1985; Lippman & Nash, 1990). One report has suggested that the use of sublingual nifedipine 10 milligrams was effective in treating 2 hypertensive reactions following the ingestion of a tyramine-containing food in a patient receiving MAOI therapy (Clary & Schweizerr, 1987). Chlorpromazine also has alpha-blocking properties and has been recommended as an agent for discretionary use (patient-initiated treatment) in the setting of dietary indiscretion (Lippman & Nash, 1990).

Dietary restrictions are required for individuals receiving monoamine oxidase inhibitor therapy to prevent a hypertensive crisis and other side effects. The foods listed in the dietary restrictions have been categorized into those foods that must be avoided, foods that may be ingested in small quantities, and those foods that were previous implicated in reactions but upon analyses of fresh samples only a small tyramine content was identified and should be safe to consume if freshness is considered.

  1. Anon: Foods interacting with MAOI inhibitors. Med Lett Drug Ther 1989; 31:11-12.
  2. Ayd FJ: Diet and monoamine oxidase inhibitors (MAOIs): an update. Int Drug Ther Newslett 1986; 21:19-20.
  3. Brown CS & Bryant SG: Monoamine oxidase inhibitors: safety and efficacy issues. Drug Intell Clin Pharm 1988; 22:232-235.
  4. Clary C & Schweizer E: Treatment of MAOI hypertensive crisis with sublingual nifedipine. J Clin Psychiatry 1987; 48:249-250.
  5. Da Prada M, Zurcher G, Wuthrich I et al: On tyramine, food, beverages and the reversible MAO inhibitor moclobemide. J Neural Transm 1988; 26(Suppl):31-56.
  6. Gilman AG, Goodman LS & Rall TW et al (Ed): Goodman and Gilman's The Pharmacological Basis of Therapeutics, 7th ed., Macmillan Publishing, New York, NY, 1985.
  7. Lippman SB & Nash K: Monoamine oxidase inhibitor update. Potential adverse food and drug interactions. Drug Safety 1990; 5:195-204.
  8. McCabe BJ: Dietary tyramine and other pressor amines in MAOI regimens: a review. J Am Diet Assoc 1986; 86:1059-1064.
  9. Stockley I: Alcohol-free beer not safe for MAOI patients. Pharm J 1993; 250:174.
  10. Zisook S: A clinical overview of monoamine oxidase inhibitors. Psychosomatics 1985; 26:240-251.

Theodore G Tong, Pharm D
C Hansen Assistant Clinical Professor of Pharmacy
University of California
San Franscisco, California 94143
Revised by DRUGDEX(R) Editorial Staff
Denver, Colorado 80204
09/82; 09/83; 07/85; 07/86; 09/89; 04/93; 01/94


The Psychotherapist's Guide to Pharmacotherapy

Date: Sat, 10 Feb 1996 18:36:02 -0800
From: Jim Ellison, MD

This table is from my book, now out of print, entitled The Psychotherapist's Guide to Pharmacotherapy.

Foods to Avoid


Medications to Avoid

(ask your physician about any other prescribed medications for safety)  

Miscellaneous discussion

From: Peter M. Brigham, MD
Date: Mon, 12 Feb 1996 16:24:23 -0500

The "Chianti is a no-no and white wine is OK" dogma is suspect, from one citation I recall from last year. I think someone did tyramine assays on various foodstuffs and found that the highest tyramine content of all the wines tested was in a California chablis! There was even considerable variation from pressing to pressing of a given wine, so generalizations seem dangerous.

Another thing I recall was that many foods -- even supposedly innocuous ones -- can have increased tyramine content if they are not fresh. That goes not only for liver, but other meats and possibly even the "OK" cheeses. As I remember there was more variability attributable to the age of foodstuffs than anything else.

Also, I recall postings about certain patients being not at all sensitive to dietary lapses, while others are very sensitive.

The overall message I've ended up with is that lists of "OK" vs "forbidden" foods are hard to trust completely and should be regarded as guidelines only. Probably carrying sublingual nifedipine is a good idea for most patients.

Date: Wed, 28 Feb 1996 16:31:48 -0600
From: Robert Hsiung

At 10:06 PM 2/26/96, George Davidson wrote:

Alcohol-free beers and wines are not alcohol-free! They have a low but definite percentage (about 0.5% I believe) of alcohol. This is enough to trigger an Antabuse reaction...

...or an MAOI reaction.

From: Eliot Gelwan
Date: Fri, 10 Jan 1997 00:27:00 -0640

The manufacturer of Eldepryl (selegiline) just sent me an amended set of prescribing information saying that it is now recommending tyramine restriction for Eldepryl users, on the basis of several reports of hypertensive crisis at therapeutic doses.

Date: Sun, 05 Jan 1997 23:01:02 -0500
From: Ivan Goldberg

Selegiline is a partially selective (MAO-B) inhibitor. At the doses prescribed for the treatment of Parkinson's disease, up to 10 mg/day, there is no need for the patient to avoid tyramine-containing foods.

When 40 mg/day is prescribed in divided doses, there is inhibition of both MAO-A and MAO-B, and an antidepressant effect is often noted. At such doses a tyramine-restricted diet is necessary. I have used selegiline, sometimes with excellent results, as an antidepressant in people who had originally been started on it, in lower doses, for Parkinson's disease.

Date: Tue, 07 Jan 1997 21:10:41 -0800
From: Frank Feiner

Be aware, however, that Somerset Pharmaceuticals, the manufacturer of selegiline (Eldepryl), reported 3 cases of hypertensive reactions in patients receiving only 5 mg BID of selegiline, 2 who had eaten "tyramine containing foods" and 1 polypharmaceutically induced. They have revised their labelling accordingly.

Date: Sun, 30 Mar 1997 21:32:01 -0500
From: Mark Rosenberg

According to "The Making of a User Friendly MAOI Diet" in J Clin Psychiatry 1996, 57: 99-104, many of the restrictions listed in your MAOI diet are without scientific merit. This article suggests an easy to follow diet that most patients are likely to understand and comply with.

Date: Mon, 31 Mar 1997 19:55:55 -0500
From: Stanley Cole

I have read the article on the new MAOI diet carefully, and they did extensive review of the literature and some of their own assays. What was lacking was any empiric validation of the diet itself. From what I could tell, the authors had not tested their hypothesis about this diet (that it is safe). We were considering changing our MAOI diet but preferred to wait to see the evidence. It is easy but is it safe?

From: Jan Weijnen
Date: Tue, 1 Apr 1997 20:55:03 MET

Another reference to a relevant paper on the MAOI-diet issue:

Tyramine content of previously restricted foods in monoamine oxidase inhibitor diets, S.E. Walker et al., J. Clin. Psychopharmacol. 1996, 16 (5): 383-388.

Date: Sat, 05 Apr 1997 14:51:24 -0500
From: Ivan Goldberg

I have reviewed the diet from the J Clin Psychiatry (1996, 57: 99-104). Here are how my experiences stack up against the suggestions in the paper:

Suggestion My experience
Hot dogs are OK. People have become hypertensive (especially when eating poorly refrigerated ones from street vendors).
Chocolate is OK American chocolate is OK in usual amounts. People have reacted to good European chocolate.
Pickled herring is OK. Many reactions to this.
8 oz of red wine is OK. Many reactions to red wines.
No mention of pastrami or corned beef. Many people have become hypertensive.
Absolute ban on say sauce. Small amounts seem OK.

The hardest thing to get patients to understand is that any protein containing food if refrigerated poorly or too long becomes dangerous. I specifically warn people about open cans of tuna or salmon and about left-over poultry.

Date: Sat, 05 Apr 1997 19:43:47 -0500
From: Mark Rosenberg

Good point about improperly stored protein foods. This point is also emphasized in the article. While no specific mention is made of corned beef and pastrami, aged and cured meats are prohibited. According to the article, no case reports of reactions to these meats have been published despite their documented high levels of tyramine. The authors postulate that perhaps other vasoconstritive phenolic amines must be present to precipitate a hypertensive crisis. They do however, recommend avoiding these foods. The authors attribute headaches from red wine to an excess of phenolic flavonoids, and state that case reports of hypertensive crises associated with wine of any type are lacking. They state that properly stored pickled herrring is low in tyramine and is safe. Perhaps reactions asociated with this food were the result of improper storage. They recomend against soy sause based on their assays of several different brands which demonstated a wide variability in tyramine content. I agree, however, that small amounts are probably safe. Do you have any more info on why European chocholate should be avoided? Have high tyramine levels been documented? Have severe hypertensive episodes been documented?

Date: Sat, 05 Apr 1997 20:32:44 -0500
From: Ivan Goldberg

The documentation of hypertensive reactions to European chocolate is only in the form of two patients I know who had hypertensive reactions after eating it. I suspect the offending substance is phenylethylamine not tyramine. American chocolate is full of milk solids and the amount of real chocolate is limited. Many of my patients with hysteroid dysphoria have discovered that they feel significantly better after eating European than American chocolate when off their MAOIs.

Date: Sat, 05 Apr 1997 20:49:46 -0500
From: William Braden

The Medical Letter piece on this (1984) notes that a sample of spoiled pickled herring had the highest tyramine content of any food measured.

From: David Mintz, M.D.
Date: Sat, 5 Apr 1997 22:27:19 -0500

Three or four days before I was going to discuss the "User Friendly MAO Diet" with a patient who was on an MAOI (he had been complaining of the restrictions of the regular diet), he ingested 4 chocolate pinwheel cookies. Within minutes, he had a pounding headache and labile hypertension (up to 180/110). While in the ER, after being medically cleared, he suffered 2 grand mal seizures. He had no seizure history, and a subsequent neurologic workup was normal. As he was an inpatient, we had a pretty good idea about the rest of his diet and found no evidence of other dietary culprits. As he was a litigious sort of fellow, I was glad that I had not yet told him he could eat chocolate in moderation. For the time being, I'm feeling like pretty much sticking with the more conservative diets.

Date: Sat, 09 Aug 1997 14:35:20 -0700
From: Frank Feiner

Having observed severe hypertension when an elderly patient of mine on Parnate (tranylcypromine) recieved codeine, I now warn all my patients on MAOIs to avoid all narcotic analgesics. However, I just did a Medline search on the interaction, which actually came up with a lot less than I expected. I still plan to continue my global warning.

Date: Sat, 09 Aug 1997 20:17:37 -0400
From: Ivan Goldberg

I have no data from studies, but my patients on MAOIs who have required emergency surgery have all done well with about 50% of the usual doses of morphine and codeine. Many of them have used acetaminophen with codeine for everyday aches and pains on multiple occasions without incident.

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[dr. bob] Dr. Bob is Robert Hsiung, MD, dr-bob@uchicago.edu

Revised: July 17, 2002
URL: http://www.dr-bob.org/tips/maoi.html