Now that summer is here, remember that many psychiatric drugs pose a risk of potentially lethal heat exhaustion or heat stroke, including antipsychotic drugs, antidepressants, and stimulants. Any drug that disrupts major neurotransmitter systems like dopamine, acetylcholine, serotonin, or histamine can disrupt heat regulation and poses a potential for causing or aggravating heat stroke. That includes almost all psychiatric drugs.

Older people are at especially high risk of fatal reactions. Epidemic deaths, often associated with psychiatric drugs, have been reported (Martin-Latry 2007, Kuzuya 2013) on hot days among the elderly in apartments and other housing without air conditioning. People of all ages are at risk when vigorously exercising in the heat. Hypotension and shock induced by heat stroke are among the causes of death or lasting organ damage, including the kidneys, liver and lungs.

If you want to know the risk of heat stroke associated with drugs you are taking, you can directly Google the drug and the effect, such as “Prozac and heat stroke” or “Abilify and heat stroke” or “Ritalin and heat stroke.” The results can be startling. Key words to search on-line include heat stroke, heat exhaustion, heat intolerance, heat sensitivity, hyperthermia, temperature dysregulation, hypothalamic dysregulation, and dehydration. You can broadly search with a term like “drug heat intolerance” or “psychiatric drug heat intolerance.”

Initial symptoms of heat exhaustion, hyperthermia and heat stroke include headache, nausea and vomiting, muscle cramps, heavy sweating, pallor, cold skin, elevated heart rate, and weakness. As the reaction worsens, symptoms include high fever, trouble breathing, hot or red skin, dehydration with lack of sweating and dark urine, fainting, collapse, and seizures. Mental symptoms include cognitive dysfunction such as confusion and delirium. In the elderly, any abrupt decline in physical or mental health and well-being on a hot day or in a hot room should raise the question of heat exhaustion.

Heat stroke is a medical emergency requiring immediate medical attention. Emergency measures under clinical supervision include emersion in a bath of cold or ice water, a cooling blanket, and/or ice packs to the groin, neck, back and armpits to lower body temperature. Shivering increases the body temperature and sedative medications can relieve them. 

Prevention is the best approach. Especially if you are concerned about elderly and otherwise impaired people in your life, even if they are living in a managed care facility, be sure to check on them during hot weather to make sure they are not suffering from heat exposure. If they are taking psychiatric drugs, they will need special attention to protect them from the risk of heat intolerance or heat stroke. People with impaired judgment and compromised physical health can rapidly decline when confined in a hot room or when their air conditioner fails. And, of course, they can always benefit from our attention!

Peter R. Breggin, MD