Theobromine poisoning

Theobromine poisoning, also wrongly called chocolate poisoning, is an overdosage reaction to the xanthine alkaloid theobromine, found in chocolate, tea, cola beverages,açaí berries, and some other foods. Median lethal (LD₅₀) doses of theobromine have only been published for humans, cats, dogs, rats, and mice; these differ by a factor of 6 across species.

Cocoa beans contain about 1.2% theobromine by weight, so an ounce (28g) of raw cocoa contains approximately 0.3g theobromine. Processed chocolate, in general, has smaller amounts. The amount found in highly refined chocolate candies or sweets (typically 1.4–2.1 g/kg or 40–60 mg/oz) is much lower than that of dark chocolate or unsweetened baker's chocolate (> 14 g/kg or > 400 mg/oz). In general, the amount of theobromine found in chocolate is small enough such that chocolate can be safely consumed by humans with a negligible risk of poisoning. However, occasional serious side effects may result from the consumption of large quantities, especially in the elderly.

Serious poisoning happens more frequently in domestic animals, which metabolize theobromine much more slowly than humans, and can easily consume enough chocolate to cause chocolate poisoning. If large numbers of filled chocolate candies are consumed, another serious danger is posed by the fat and sugar in the fillings, which can sometimes trigger life-threatening pancreatitis several days later. The most common victims of theobromine poisoning are dogs, for which it can be fatal. The toxic dose for cats is even lower than for dogs. However, cats are less prone to eating chocolate since they are unable to taste sweetness. Theobromine is less toxic to rats, mice, and humans, who all have an LD₅₀ of about 1,000 mg/kg.

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