Dr Somya Pandey, Specialty Doctor at Cygnet Hospital Harrow, breaks down why hot weather is a particularly difficult time for antidepressant takers and issues five top tips on staying safe this summer.
Why can antidepressants make hot weather more difficult?
Some antidepressants can affect the body’s ability to regulate its temperature, making it harder to respond effectively to heat. Understanding how your medication may interact with hot weather can help reduce the risk of dehydration, heat exhaustion and other heat-related illnesses.
For most people, when temperatures rise, the hypothalamus – the body’s internal thermostat – sends signals to cool the body down. This includes triggering sweating, widening blood vessels near the skin and encouraging fluid intake. However, some antidepressants can affect these natural cooling processes.
How can antidepressants affect you in hot weather?
Different antidepressants can affect how the body responds to heat. This may increase the risk of dehydration, overheating and heat-related illness during periods of hot weather.
For example:
- SSRIs, such as sertraline, fluoxetine and citalopram, can increase sweating, leading to greater fluid loss and a higher risk of dehydration.
- SNRIs, including venlafaxine and duloxetine, may also cause excessive sweating, particularly during warmer weather.
- Tricyclic antidepressants, such as amitriptyline and nortriptyline, can reduce sweating, making it harder for the body to cool itself effectively and increasing the risk of overheating.
These side effects do not outweigh the benefits of antidepressants, which can be life-changing medications for many people. However, they do mean that extra care may be needed during periods of hot weather and heatwaves.
5 tips for staying safe in hot weather while taking antidepressants
1. Drink water before you feel thirsty
Some antidepressants may reduce a person’s awareness of thirst. To avoid dehydration, drink water regularly throughout the day, particularly during hot weather or a heatwave.
It’s also advisable to limit alcohol and caffeine, as both can contribute to fluid loss.
2. Avoid the hottest part of the day
In the UK, temperatures are typically highest between 11am and 3pm.
Where possible, plan outdoor activities for the early morning or evening when conditions are cooler and more comfortable.
3. Understand how your medication affects sweating
Different antidepressants can affect sweating in different ways. Some increase sweating while others reduce it.
Both effects can create challenges during hot weather. If you are unsure how your medication may affect you, speak to your GP, pharmacist or prescribing clinician.
4. Protect your sleep during hot weather
Quality sleep is important for both physical wellbeing and mental health. Poor sleep can worsen symptoms of depression and anxiety, while hot weather can make it more difficult to get adequate rest.
Keeping your bedroom cool, using a fan, choosing lightweight bedding and opening windows at night can help improve comfort and support better sleep.
5. Plan ahead during a heatwave
Simple planning can reduce the risk of heat-related illness.
Carry water with you, wear loose-fitting and light-coloured clothing, and know where your nearest cool indoor space is, such as a library, supermarket or air-conditioned building.
Don’t forget to apply sunscreen, as sunburn can impair the skin’s ability to regulate body temperature.
Signs of heat-related illness to look out for
If you take antidepressants, or care for someone who does, it’s important to recognise the warning signs of heat-related illness.
Heat exhaustion symptoms
Symptoms of heat exhaustion can include:
- Heavy sweating
- Pale or clammy skin
- Weak pulse
- Nausea
- Dizziness
- Muscle cramps
- Feeling faint
If someone develops these symptoms, move them to a cool place, encourage them to rest and slowly sip fluids.
Heat stroke symptoms
Heat stroke is a medical emergency.
Signs include:
- A body temperature above 40°C
- Hot, red skin
- A strong, rapid pulse
- Confusion
- Loss of consciousness
If you suspect heat stroke, call 999 immediately.
Serotonin syndrome symptoms
Serotonin syndrome is a serious condition that can occur when serotonin levels in the nervous system become dangerously elevated, particularly if antidepressants are combined with certain other medications.
Because symptoms can resemble heat exhaustion, it is important not to dismiss them as being solely caused by hot weather.
Symptoms may include:
- Agitation or restlessness
- Muscle twitching, jerking or rigidity
- Rapid heart rate
- High temperature
- Tremors
- Exaggerated reflexes
- Confusion
- Loss of coordination
Don’t stop taking antidepressants without medical advice
Although antidepressants, like all medications, can have side effects, they remain effective and often life-changing treatments for many people.
Do not stop taking or change your antidepressant medication without first speaking to your doctor or prescribing clinician.
If you are struggling to cope with hot weather while taking antidepressants, seek advice from your GP, pharmacist or mental health team. In an emergency, call 999.