A pharmacist has issued a warning to people taking certain antidepressants as the UK braces for temperatures up to 35°C. Dipa Kamdar, Senior Lecturer in Pharmacy Practice at Kingston University, highlighted that selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) can interfere with the body's ability to regulate temperature.
SSRIs such as sertraline, fluoxetine (Prozac), and citalopram, as well as TCAs like amitriptyline, nortriptyline, and lofepramine, may affect sweating. Kamdar explained that these drugs can cause heat intolerance by disrupting the hypothalamus, which controls body temperature, or by altering neurotransmitter levels that influence sweat gland activity.
Up to 14% of antidepressant users experience increased sweating as a side effect, but this can paradoxically lead to dehydration if fluids are not replaced. Conversely, some users may sweat less, impairing cooling. Kamdar stressed that any disruption to sweating, a key cooling mechanism, raises the risk of heat-related illness.
The warning comes as the Met Office forecasts temperatures reaching 35°C in southern England and Wales, following the UK's hottest May day on record. Senior meteorologist Becky Mitchell noted that 97 sites exceeded 30°C on Monday, with the previous May record of 32.8°C set in 1922 and 1944 being broken.
Kamdar also cautioned about other medications, including antipsychotics, beta-blockers, and diuretics, which can impair heat regulation. Antipsychotics may blunt the sensation of overheating, while beta-blockers reduce blood flow to the skin, and diuretics increase dehydration risk. She advised patients to stay hydrated, avoid peak sun, and consult their pharmacist if concerned.
