Drug-induced hyperthermia

Drug-induced hyperthermia is a condition characterized by an abnormally high body temperature resulting from the administration of certain drugs. This condition can range from mild to severe and, in extreme cases, can lead to significant morbidity or mortality. Drug-induced hyperthermia is distinct from fever, as it does not involve the pyrogen-mediated increase in the body's temperature set point.

Causes

Drug-induced hyperthermia can be caused by a variety of pharmacological agents, including but not limited to:

• Amphetamines and related substances, which increase metabolic activity
• Anticholinergics, which impair sweating and thus heat dissipation
• Serotoninergic drugs, such as certain antidepressants, which can lead to Serotonin Syndrome, a condition characterized by high body temperature among other symptoms
• Neuroleptic drugs, which can lead to Neuroleptic Malignant Syndrome, another serious condition associated with hyperthermia

Pathophysiology

The pathophysiology of drug-induced hyperthermia varies depending on the drug involved. For example, amphetamines increase metabolic rate, leading to increased heat production, while anticholinergics reduce the body's ability to dissipate heat by impairing sweating. Serotonin syndrome and neuroleptic malignant syndrome involve complex interactions between neurotransmitters and receptors in the brain, leading to a dysregulated thermal set point and increased muscle activity, both of which contribute to elevated body temperature.

Symptoms

Symptoms of drug-induced hyperthermia can include:

• High body temperature
• Sweating (except in cases caused by anticholinergics)
• Confusion or delirium
• Muscle rigidity
• Rapid heart rate
• Nausea or vomiting

Diagnosis

Diagnosis of drug-induced hyperthermia involves a thorough medical history, including a list of all medications the patient is taking, and a physical examination. Laboratory tests may be conducted to rule out other causes of elevated body temperature and to assess the severity of the condition.

Treatment

Treatment of drug-induced hyperthermia focuses on:

• Discontinuing the offending drug
• Supportive care to lower body temperature, such as cooling blankets or ice packs
• Hydration to prevent dehydration
• In severe cases, medications may be administered to control symptoms, such as muscle relaxants for muscle rigidity

Prevention

Prevention of drug-induced hyperthermia involves careful prescription and monitoring of drugs known to cause hyperthermia, particularly in patients at higher risk due to existing medical conditions or concurrent use of other medications that may increase the risk.

See also

• Hyperthermia
• Serotonin Syndrome
• Neuroleptic Malignant Syndrome
• Anticholinergic Syndrome