Syrian rue (Peganum harmala) is a perennial from the Middle East and North Africa. Its seeds contain several alkaloids including harmaline, harmine, and tetrahydroharmine (18). Harmine and harmaline, mem- bers of the beta-carboline chemical class, are both potent reversible inhibitors of the enzyme monoamine oxidase (MAO) (19 – 21).
Monoamine oxidase inhibitor toxicity is initially characterized by hyperther- mia, tachycardia, and agitated delirium; these findings arise from excess sympathomimetic tone secondary to inhibited enzymatic degradation of catecholamine neu- rotransmitters. Rhabdomyolysis occurs as a conse- quence of increased muscle activity. Widely fluctuat- ing vital signs and depression of mental status occur as catecholamine stores are consumed. The period during which recovery occurs—typically several days in duration—coincides with restored synthesis of sympa- thomimetic neurotransmitters. Except for hypertension, which is seen in severe cases, this patient demonstrated all aspects of MAOI poisoning.