Is chocolate intake contraindicated during Nardil treatment?/nA 20-year-old female with obesitas, b

Fråga: Is chocolate intake contraindicated during Nardil treatment?

A 20-year-old female with obesitas, border-line psychosis and depression is being treated with phenelzine (Nardil) 15 mg 2+1+2 and no other drugs. She has low blood pressure (80/60 mmHg). The patient is fond of chocolate and the question is whether chocolate intake is an absolute contraindication.

Sammanfattning: Chocolate does not contain tyramine but some phenylethylamine and methylxanthines. There is only one single case report suggesting a hypertensive reaction in association with chocolate and MAO inhibitors. This patient had, however, also eaten cheese. If the blood pressure is checked regularly and the patient is aware of the risk, a moderate intake of chocolate cannot be considered contraindicated.

Svar: Phenelzine, as well as other old unselective monoaminooxidase inhibitors, requires dietary restrictions. The most important is to avoid tyramine-rich food since tyramine is a vasopressor amine which is inactivated by MAO. Well-known examples of food that may contain high levels of tyramine are red wines, cheese and many fermented products (1). Apart from tyramine the intake of sympatomimetics and dopaminergic drugs should be restricted since these combinations may also cause hypertensive crisis (2,3). Furthermore, opioids and alcohol should be avoided (3).

Chocolate does not contain measurable amounts of tyramine (4,5). Chocolate does however contain phenylethylamine and this compound has been suggested to precipitate migraine (4). The phenylethylamine content is, however, only 0-7 mg/kg (5). In comparison, 20-60 mg/kg is found in for example salami, many cheeses and pickled herring (5). Chocolate also contains some methylxanthines. Methylxanthines may act as indirect sympatomimetics. However, the methylxanthine content in chocolate is also low. Even though MAO inhibitor-treated patients may be more sensitive to the effects of phenylethylamine and methylxanthines it is probable that the only intake of large amounts of chocolate could cause measurable effects on blood pressure. In Physician´s Desk Reference (3) it is stated that excessive amounts of caffeine or chocolate may also cause hypertensive reactions.

There is only one case report of a hypertensive crisis after chocolate intake (60 gram) by a woman who had recently eaten cheese (see 4). Thus, the cause-effect relationship is not clear.

Being aware of the potential risk, increasing the observance of symptoms such as headache and following the blood pressure reaction, moderate intake of chocolate cannot be regarded as a contraindication to phenelzine treatment. 1 McCabe BJ: Dietary tyramine and other pressor amines in MAOI regimens: A review. J Am Diet Ass 1986; 86: 1059-1064 2 Sjöqvist F: Toxic interactions between monoamine oxidase inhibitors (MAOI) and other drugs. Proceedings of the 3rd International Pharmacological Meeting July 24-30, 1966. Monoamine Oxidase Inhibitors. Pergamon Press, Oxford 1968; 10: 61-74 3 Physicians Desk Reference (PDR). 1993; 1793-1794 4 Stewart MM: MAOIs and food - fact and fiction. Adv Drug Bull 1976; 200-203 5 Biogena aminer - nr 8. Information om livsmedel som kan ge överkänslighetsreaktioner. Statens Livsmedelsverk 1992