Nutmeg is one of the two spices derived from the dried seeds of the evergreen tree Myristica fragrans, which is indigenous to the Spice Islands of Indonesia but is now widely cultivated across the tropics and South America. Since medieval times, it has been used as a stimulant, carminative (relieves flatulence), emmenagogue (induces menstruation), and abortifacient. Recently, it has been used to control diarrhea associated with medullary thyroid carcinoma. However, its primary use is as a spice in winter dishes.
Myristicin and elemicin are the primary ingredients in ground nutmeg and thought to be responsible for the psychologic and physiologic effects observed. The symptoms seen with acute intoxication resemble anticholinergic toxicity. The more common central nervous system effects are visual hallucinations, headache, dizziness, drowsiness, anxiety, fear, psychotic episodes, dissociation, hostile behavior, and seizures. Cardiovascular effects include sinus tachycardia, hypotension, and flushing. In addition, nausea and vomiting frequently occur. In contrast to anticholinergic toxicity, nutmeg intoxication is more likely to cause miosis than mydriasis. Several deaths have been reported, although this is extremely rare.