Millions of individuals taking common antidepressant medications may find themselves more susceptible to the effects of heatwaves, according to health experts. Selective serotonin reuptake inhibitors (SSRIs), a class of drugs that includes sertraline, citalopram, and fluoxetine, are prescribed to over 8.7 million people in England alone.
These medications work by increasing serotonin levels in the brain. However, they can also affect the hypothalamus, the region of the brain responsible for regulating body temperature. This interference can make it more difficult for the body to cool itself down, particularly during periods of extreme heat.
Dr. Helen Wall, an NHS GP, explains that SSRIs can impact the body's natural sweating mechanisms. Some individuals may sweat excessively, increasing the risk of dehydration, while others may sweat less, hindering the body's ability to dissipate heat. Both scenarios can be problematic during heatwaves.
Furthermore, SSRIs can interfere with saliva production, leading to a dry mouth. This can confuse normal thirst signals, causing some individuals to focus on feeling overheated or nauseous rather than recognizing their need for fluids. Even without feeling thirsty, the body can lose significant amounts of fluid through sweating and respiration, leading to dehydration without the user realizing it.
Women may experience exacerbated heat intolerance due to hormonal fluctuations, which can intensify the effects of SSRIs on thermoregulation. The author of the article, Alice Snape, who takes sertraline for depression, anxiety, and OCD, describes struggling with intense sweating, dehydration, and cognitive fog during recent heatwaves, attributing it to her medication.
To mitigate these effects, Dr. Wall recommends several strategies. Individuals are advised to set alarms to remind themselves to drink fluids, even if they don't feel thirsty. Consuming drinks with electrolytes, such as coconut water, can help replace salts lost through sweat. Exercising only in the early morning or late evening when temperatures are lower is also suggested.
Applying a damp towel to pulse points like the neck and wrists can help cool blood flow. Opening windows only at night to allow cool air to circulate can also provide relief. It is crucial not to skip medication doses, as withdrawal symptoms can include dizziness, headaches, nausea, fatigue, brain fog, and a return of underlying mental health conditions. Skipping doses can also be exacerbated by heat.
If heat intolerance becomes a significant issue, individuals should consult their GP. Heat exhaustion can progress to heat stroke, a medical emergency. Dr. Wall also advises reducing alcohol consumption, as it can contribute to dehydration.