Susie asked
My mother is 95 yrs old and has been taking Parnate most of her adult life, however she is now in a Nursing home after a fall and 4 months in Hospital. The home have printed off a list of about 25 foods she is not allowed to eat which include chicken, beef, fish, yogurt, soup etc. All these foods I have given her with no ill effect and was also allowed to eat in Hospital. I know she musn't eat cheese, broad beans, oxo, bisto, marmite and that has been followed religiously over the years. Your insight would be greatly appreciated.
Answer
Parnate (tranylcypromine) belongs to a class of medications known as MAOIs (Monoamine Oxidase Inhibitors). MAOIs are very effective drugs for treating major depressive disorders but unfortunately have numerous food and drug interactions that can cause severe adverse reactions.
Perhaps the most well known interaction with any drug in the MAOI class are with foods that contain high levels of tyramine. Therefore, intake of high tyramine foods need to be restricted while taking MAOI medications.
Consuming foods high in tyramine can put patients at risk of hypertensive crisis (i.e. very high blood pressure). Sources differ in regard to high much tyramine is safe to consume. Most state a safety threshold of less than 6 to 10 mg per serving. The problem is that it is extremely difficult to decipher the exact amount of tyramine contained in different foods. Therefore, the product labeling for most MAOI drugs simply list foods to avoid if they have ever been associated with high tyramine levels. Below is a sample list of foods to avoid while taking MAOI drugs:
- Aged Cheese
- Yeast Extract
- Fava Beans
- Pickled Meats
- Smoked Fish
- Fermented Sausage
- Bananas
- Raisins
- Canned Figs
- Soy Sauce
In addition, improper storage or handling of foods may increase tyramine content, adding even more ambiguity to safe eating choices. Lastly, it is generally recommended to avoid alcohol (as many beverages have a high tyramine content such as many hard liquors) and caffeine as these all may predispose a patient to hypertensive crisis.
Most institutions tend to stay on the safer side of dietary restrictions, even though the risk of high tyramine content may be low. In fact, over the years, the vast inclusion of restricted foods has been re-evaluated and many previously excluded foods may be OK to consume in moderate quantities. For example, many old sources will state that all milk products must be avoided. However, independent analysis has shown that many milk products such as sour cream, yogurt, and processed cheese slices contain little to no tyramine, even though they were initially listed as restricted foods. You mentioned chicken and beef on the list your mother received. In general, it has been shown that fresh, unspoiled chicken and beef contain very small amounts of tyramine and are most likely OK.
It should be noted also that there is a large amount of variation among people in regard to their tyramine sensitivity. Some people may get a reaction with as little as 6 mg of tyramine while others can consume considerably more with no problems. Your mother may be less sensitive.
Overall, it is not surprising that you/your mother were handed a broad list of foods that may not be consumed while on therapy with Parnate. It is often on the safer side to have a blanket policy/rules regarding dietary restrictions in patients taking MAOIs, even though many restricted foods may in fact be OK in some people. I would recommend that you/your mother speak with the prescribing doctor to discuss your concerns regarding the dietary restrictions imposed.
