Hypothermia in a combined intoxication with doxepin and moclobemide in an adolescent

Intoxication with antidepressants, frequently encountered in pediatric emergency medicine, can often lead to life threatening situations. While hyperthermia, hypertonicity and rigidity are symptoms indicative of a serotonin syndrome triggered by an intoxication with serotonin reuptake inhibitors or monoamine oxidase inhibitors, cardiotoxicity, coma and ECG changes are typical of an intoxication with tricyclic antidepressants.

Hypothermia (instead of the expected hyperthermia) is described for the first time as a persistent symptom during the course of a combined moclobemide-doxepin intoxication in an attempted suicide of a 16-year-old adolescent.

The administration of serotonin reuptake inhibitors alone or in combination with other medication which increases the level of 5-hydroxytryptamine, i.e. serotonin, in the synaptic cleft mainly leads to hyperthermia. According to a recent study, however, the application of a selective 5-HT(1a) agonist to transgenic mice with a prominent overexpression of the 5-HT(1a) receptor lead to immobility and hypothermia. These findings might help to explain the hypothermia observed in the case of the intoxicated 16-year-old.

Intoxication with antidepressants should not be excluded a priori in a hypothermic patient who displays other clinical signs of the said intoxication.