Pharmacist issues heatwave warning for anyone taking these common medications

A pharmacist has issued an important warning to anyone using any of these medications during a heatwave.

The UK has seen its third heatwave in three months, and it recorded its eighth day at or above 34°C in a calendar year, breaking the previous high of seven days set in the summer of 1976 and in 2020.

Amidst warnings over heat exhaustion, dehydration and hosepipe bans, Jason Murphy, Head of Pharmacy at leading online pharmacy Chemist4U, also outlined a list of the everyday medications that could be affected by the heatwave, and what people can do to stay safe.

"With temperatures climbing again this week and heat-health alerts back in place, it’s really important that people on regular medication stop and think about how the heat might be affecting them," the expert explained.

A pharmacist has issued a warning to anyone using any of these medications during a heatwave (Getty Stock Images)

SSRIs

"The one I’d particularly flag is SSRIs (sertraline, citalopram, fluoxetine and the like), which are among the most widely prescribed medicines in the UK," Jason outlined.

While they can be life-changing medications for a lot of people, they can interfere with your hypothalamus - AKA the part of your brain that regulates your body temperature.

"This can mean you may sweat more or less than usual, feel dizzy, or just not realise how dehydrated you’re getting until it catches up with you," he added.

A number of medications are 'sensitive to temperature' (Getty Stock Images)

Hormonal contraception

Those taking hormonal contraception should also be aware of what the heat can do to their medication.

Jake outlined: "Hormonal contraception, like the combined pill, the mini pill, the patch, and the vaginal ring, all contain oestrogen and/or progestogen, and those hormones are sensitive to temperature. Most are designed to be stored below 25°C, and prolonged exposure above 30°C can start to break down the hormones and reduce how well they work.

"So, a pill packet that’s spent a few days in a hot car, a handbag or beach bag, a steamy bathroom cabinet, or a windowsill isn’t necessarily going to protect you the way you’d expect; there’s a very real risk of unintended pregnancy as a result.

"If your pills look discoloured, feel sticky or softer than usual, or the packet’s been sitting somewhere hot for a while, it’s much safer to treat them as compromised, start a new pack and use a backup method like condoms for at least seven days."

The expert also noted: "While it’s important that you don’t stop taking any prescription medications due to the heat, make sure you’re aware of how they might react to the heat. If something doesn’t feel right, make sure you speak to your pharmacist or GP. "

The UK has recorded its eighth day at or above 34°C in a calendar year (Tyla)

Commonly prescribed medications that can be affected by the heat

• SSRI antidepressants – can impair temperature regulation, sweating and hydration
• SNRI antidepressants – linked to excessive sweating and dehydration
• Tricyclic antidepressants – reduce your body’s ability to sweat and cool down
• GLP-1 medications – prolonged heat exposure can break down the peptide structure, meaning your dose could be lower than intended, and could make you feel less thirsty than you usually would
• Diuretics – increase the amount of fluid your body loses, and increase your risk of dehydration
• Beta-blockers – can blunt your body’s cardiovascular response to the heat
• ACE inhibitors and ARBs – can affect your blood pressure regulation and hydration in the heat
• ADHD stimulants – can increase your body’s temperature and metabolism, and alter how you sweat
• Insulin – heat can degrade insulin and cause faster absorption, raising the risk of hypoglycaemia
• Hormonal contraception – heat above 25°C can degrade the hormones and reduce effectiveness
• Inhalers and EpiPens – heat can damage the active ingredients and delivery mechanism, so they may not work when you need them
• Sun-sensitising medicines – including some antibiotics, retinoids, diuretics, and certain antidepressants, which can make your skin burn faster in the sun