Theobromine poisoning
Theobromine poisoning is an overdosage reaction to the xanthine alkaloid theobromine, found in chocolate, tea, cola beverages, and some other foods.
Signs and symptoms
Mild-to-moderate symptoms include sweating, trembling and severe headaches. These occur at theobromine doses of per day, such as may be found in of cocoa powder.Severe symptoms include cardiac arrhythmias, epileptic seizures, internal bleeding, heart attacks, and eventually death.
Pharmacology
Theobromine has a biological half-life of, with unmodified after a single dose of.Other animals
Toxicity
The median lethal dose of theobromine has only been published for cats, dogs, rats, and mice; these differ by a factor of 6 across species.Serious poisoning happens more frequently in animals, which metabolize theobromine much more slowly than humans, and can easily consume enough chocolate to cause poisoning. The most common victims of theobromine poisoning are dogs, for whom 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 and mice, who all have an LD50 of about.
In dogs, the biological half-life of theobromine is 17.5 hours; in severe cases, clinical symptoms of theobromine poisoning can persist for 72 hours. Medical treatment performed by a veterinarian involves inducing vomiting within two hours of ingestion and administration of benzodiazepines or barbiturates for seizures, antiarrhythmics for heart arrhythmias, and fluid diuresis. Theobromine is also suspected to induce right atrial cardiomyopathy after long term exposure at levels equivalent to approximately of dark chocolate per day. According to the Merck Veterinary Manual, baker's chocolate of approximately of a dog's body weight is sufficient to cause symptoms of toxicity. For example, of baker's chocolate would be enough to produce mild symptoms in a dog, while a 25% cacao chocolate bar would be only 25% as toxic as the same dose of baker's chocolate. One ounce of milk chocolate per pound of body weight is a potentially lethal dose in dogs.