Managing medications in hot weather

Periods of extreme heat can significantly affect clients’ health and the way their medicines work. Heat impacts medication storage, increases the risk of dehydration, and may reduce the body’s ability to thermoregulate, particularly for people with chronic conditions such as diabetes. This guide summarises important points to discuss with clients so they stay safe when temperatures climb.

By Donna Itzstein, Pharmacist and Credentialled Diabetes Educator

1. Storing medicines safely in hot conditions

Many medicines remain stable below 25–30°C, but extreme heat can degrade certain medications and devices.

General storage advice

• Encourage people to keep medicines in a cool, shaded place, ideally in air‑conditioned rooms.
• Avoid storage areas prone to heat and humidity, such as bathrooms, near stoves, or on top of refrigerators.
• Advise clients to keep products in their original packaging.
• Remind clients never to leave medicines, blood glucose meters, or test strips in hot cars.

Insulin considerations

• Unopened insulin should be refrigerated between 2–8°C, away from freezer compartments and fridge doors.
• Once opened, insulin can be kept cool using evaporative cooling pouches, or in an airconditioned room. Discourage insulin pens in pockets as body temperature is too warm.
• If blood glucose levels rise unexpectedly, consider heat‑damaged insulin as a possible cause.
• Insulin pumps may require more frequent reservoir changes during hot weather.

2. Medicines that increase sun sensitivity

Some medications can cause photosensitivity, increasing the risk of sunburn and skin reactions.

Classes and examples include:

• Diabetes medications: gliclazide, glipizide, glibenclamide, glimepiride
• Antibiotics: doxycycline, griseofulvin
• Cardiac/lipid medications: amiodarone, atorvastatin, fenofibrate, furosemide
• Topical preparations: retinoids, tar preparations, diclofenac gels
• Other medications: prochlorperazine, St John’s Wort

Advise clients to practise sun safety by wearing protective clothing, applying sunscreen, and avoiding peak UV times.

3. Medicines that increase the risk of dehydration

Heat can compound fluid loss, and certain medications further increase this risk. Carefully consider body fluid volume in clients with heart failure during hot weather.

Diuretics and cardiac medications

• Hydrochlorothiazide
• Furosemide
• Spironolactone

Diabetes medicines (SGLT2 inhibitors)

• Dapagliflozin
• Empagliflozin

Medicines that reduce thirst perception

• ACE inhibitors: perindopril, ramipril
• ARBs: candesartan, irbesartan, valsartan, telmisartan
• GLP‑1 receptor agonists: semaglutide, dulaglutide

Encourage adequate hydration unless the client has fluid restrictions.

4. Medicines that reduce heat tolerance

Some medicines impair the body’s ability to cool itself.

Beta‑blockers

• Propranolol, metoprolol, atenolol, carvedilol, bisoprolol

Other relevant classes

• Antidepressants: sertraline, citalopram, escitalopram, fluoxetine, paroxetine, amitriptyline, venlafaxine
• Neurological agents: carbidopa/levodopa, methylphenidate
• Bladder agents: oxybutynin
• Antiplatelets: clopidogrel

Discuss signs of heat intolerance with your clients, such as reduced sweating or dizziness.

5. General safety tips

• Do not stop medications abruptly. Advise patients to consult their doctor or pharmacist first.
• Stay hydrated. Slower urination or darker urine may signal dehydration.
• Avoid alcohol, which worsens dehydration and heat intolerance.
• Keep cool. Use fans or air‑conditioning, close blinds, wear light clothing, and avoid outdoor activities at peak heat times.
• Protect skin with sunscreen, hats, and sun‑protective clothing.
• Clients with increased frailty are most at risk in hot weather.

References

1. Australian Government, Department of Health. Therapeutic Goods Administration. Stability testing for prescription medicines version 1.1. [Online] March 2017. https://www.tga.gov.au/sites/default/files/stability-testing-prescription-medicines.pdf.
2. Photosensitizing drug reactions. Simone Montgomery, Scott Worswick. 1, s.l. : Elsevier, January 2022, Clinics in Dermatology, Vol. 40, pp. 57-63. 0738-081X.
3. Increased risk of hospital admission for dehydration or heat-related illness after initiation of medicines: a sequence symmetry analysis. Kalisch Ellett, L.M., Pratt, N.L., Le Blanc, V.T., Westaway, K. and Roughead, E.E. 2016, Journal of Clinical Therapeutics, Vol. 41, pp. 503-507.