As heatwaves across Europe increased in frequency this summer, the vital role played by community pharmacists in advising patients around medication storage and staying safe during periods of hot weather came into sharp focus. Niamh Cahill reports
As a nation that pays close attention to the weather as something of a national pastime, the sunshine certainly helped to lift everyone’s mood in the summer months.
According to Met Éireann, Ireland experienced the driest July on record this year and the second-hottest July since 1900.
Indeed, summer 2026 will go down as one of the hottest and driest in Irish living memory.
But is has not been smiles all round. Periods of extreme high temperatures led to drought and wildfires here and in many European countries.
Europe is warming twice as fast as other continents, heating up at more than double the global average rate. In June, Europe experienced one of its worst heatwaves to date.
According to the World Health Organisation (WHO), over the past 20 years there has been a 30 per cent rise in heat-related mortality.
Germany, France, Italy and Spain this summer recorded more than 25,000 likely heat-related deaths, according to new statistics.
Heatwaves are becoming increasingly common due to climate change, which means that efforts to respond effectively to ensure medication stability is maintained and that patients are aware of the impact of heat on them and their medications must be enhanced.
Advisory Role
As the most accessible healthcare professionals, pharmacists provided an important advisory role to patients during such periods of intense heat.
Rory O’Donnell MPSI of O’Donnell’s Pharmacy Gweedore, Co Donegal, told Irish Pharmacist (IP) that medicines designed to be stored at room temperature undergo accelerated storage testing during development where the temperature and pressure are increased.
He explained that this phase of testing helps the manufacturer determine the expiry date of a medicine.
“Countries such as Spain and Italy normally experience greater temperatures than Ireland and it is largely the same medicines that are marketed there,” he remarked.
Pharmacies monitor fridge and dispensary temperatures daily to limit risks to medicine storage and when items that need to be stored in the fridge are dispensed patients are advised to follow storage instructions.
“Medicines that are stored in the pharmacy fridge, such as GLP-1s and insulin, should not be left in hot conditions, such as a locked vehicle on a hot day for long periods of time. I haven’t come across this, but there is potential for these medicines not to work if stored in this way,” Mr O’Donnell stated.
But even with one-to-one advice and patient information leaflets, harmful incidents can occur.
“What I think may be more common are photosensitivity reactions whereby patients on certain medicines, for example Doxycycline, get a rash from exposure to direct sunlight. We have had a few circumstances of this where we had to advise patients accordingly, but again, it is the same advice given to anyone going on a sun holiday who is taking certain medication,” Mr O’Donnell explained.
‘What I think may be more common are photosensitivity reactions whereby patients on certain medicines get a rash from exposure to direct sunlight’
Medicine Stability
A spokesperson for the IPU told IP that pharmacists, as medicines experts, are very aware of the effect of medicines on the body and of the effect of temperature on medicines stability. “Medicines come with Patient Information Leaflets which contain information relating to both the use and storage of the medicine(s),” the spokesperson stated.
“During periods of hot weather, leaving medicines in direct sunlight, hot cars or warm rooms can affect their quality and how well they work. Some medicines can make people more vulnerable to heat as they can increase dehydration, lower blood pressure, reduce sweating or impair the body’s ability to regulate temperature.
“Pharmacists routinely counsel patients on these topics, and they identify people at higher risk and provide individual advice. If in doubt, people should check the information leaflet for their specific medicine(s) and seek advice from their pharmacist.”
In an article in the Journal of Pharmacoepidemiology and Drug Safety titled ‘Climate Change and Medications: Implications for Clinical Practice, Healthcare Sustainability, and Pharmacoepidemiology’, the authors outlined how extreme heat can threaten the stability of medications.
Published in July, the article stated: “Extreme heat, extreme weather, and supply chain disruption are concrete threats to drug stability and access.”
The authors went on to highlight how certain drugs are more affected by heat than others and the impact this can have on patient wellbeing.
“Many drug classes may increase heat-related illness risk by affecting thermoregulation (eg, cutaneous vasodilation, sweating, and cold-seeking behaviours) or fluid and electrolyte balance. For example, diuretics and angiotensin-converting enzyme inhibitors may blunt thirst sensation, and selective serotonin reuptake inhibitors and anticholinergics impair sweating. Heat exposure can cause dehydration and renal injury that may reduce clearance of renally excreted medications.”
Pharmacists and other healthcare professionals are acutely aware of the risks posed to health by heatwaves. The general public is much less aware of the risks however, particularly in Ireland, where until recent times heatwaves have been infrequent.
Awareness
In a bid to increase awareness and reduce heat-related deaths, European health policy experts have called on countries to introduce co-ordinated and comprehensive plans to respond effectively when periods of intense heat occur.
In June, the World Health Organisation (WHO) published the second edition (the first was published in 2008) of its Heat-Health Action Plan Guidance document.
It called on countries to develop heat-health action plans to reduce heat-related morbidity and mortality.
The guidance document outlines eight elements that should be included in heat-health action plans, including: Governance; heat health warning system; populations at increased risk; communication, health system resilience; reducing heat exposure; heat health surveillance; and monitoring evaluation and learning.
Plans should also provide action briefs for priority sectors and include a health message bank with ready-to-use messages for the public, the WHO advised.
“When well designed and implemented, they [heat-health action plan] help to anticipate and prepare for heat-health impacts, protect populations at increased risk, strengthen health system resilience, and reduce avoidable illness and deaths.”
No such plan exists in Ireland currently, however. A spokesperson for the Department of Health declined when contacted to comment on whether such a plan was being considered by Government.
Advice is provided by pharmacists and healthcare professionals currently, with more general heat-related health advice published by the HSE as the need arises.
According to an advisory notice published by the HSE Health Protection Surveillance Centre in June titled ‘Heat Health Advice for Healthcare and Residential Care Facilities’, during heatwaves, patients taking medications that may increase susceptibility to heat-related illness are vulnerable.
These include patients on medication that affect their heart or kidney function, their ability to sweat, or their cognition or behaviour. “Particular care may be required for patients taking medications that affect fluid balance, thermoregulation or cardiovascular function,” the notice stated.
A spokesperson for the Department of Health told IP that it advises patients to follow the storage instructions provided with their medicines and to consult a pharmacist or other healthcare professional if they have concerns about medicine storage during periods of hot weather.
“Medicines should be stored in accordance with the conditions specified by the manufacturer to help ensure their quality, safety and effectiveness,” the spokesperson stated.
“Pharmacists play an important role in advising patients on the safe and effective use of medicines, including appropriate storage requirements.
“Patients who are concerned about how their medicines may interact with hot weather should consult their pharmacist, GP or other healthcare professional.”
In the UK, the Specialist Pharmacy Service is made up of pharmacy professionals and support staff commissioned by NHS England to provide advice and guidance on medicines optimisation. No such group exists in Ireland.
In July, they issued advice on how hot weather can affect the body’s responses to some medicines and medical devices.
This followed a safety alert from the Medicines and Healthcare Products Regulatory Agency (MPRA) in the UK in June, offering advice to patients on how to manage their medications during heatwaves.
The detailed and comprehensive advisory directed patients to keep medications out of cars and direct sunlight.
“If your medicine has changed colour, developed an unusual smell, changed texture, or looks different in any way, this could signal heat damage. Ask your pharmacist for advice,” the notice stated.
Hydration
Patients taking diuretics or blood pressure medication in particular were advised to drink more water and stay cool. Lastly, it advised patients to check if their medication increased their risk of sunburn.
“Some common medicines can make your skin much more likely to burn, even in mild sunshine. This includes some antibiotics, diuretics, antidepressants, or skin treatments for acne or eczema,” the advisory stated.
Patients taking diuretics or blood pressure medication in particular were advised to drink more water and stay cool
“One medicine that requires particular care is methotrexate, used to treat conditions like rheumatoid arthritis, psoriasis, Crohn’s disease and cancer. It can cause extreme skin sensitivity to the sun – even at low doses. This can lead to painful rashes, blistering, or swelling that looks like severe sunburn. In rare cases, these reactions have led to serious infections.”
The notice also stated: “It’s not just medicines – some medical devices can also be affected by heat or humidity. For example, blood glucose monitors may give people managing diabetes less reliable readings if used or stored in hot conditions”.
A spokesperson for the HPRA underlined that the authority has an ongoing role in communicating information relating to the quality, safety and efficacy of medicines, including through product information, safety communications and other regulatory channels where appropriate.
“The approved product information for medicines, namely the summary of product characteristics (SmPC) for healthcare professionals and package leaflet (PL) for patients, provides the approved information on storage conditions and any relevant warnings or precautions associated with the use of individual medicines,” the spokesperson stated.
But the HPRA does not routinely issue general public health advice on managing high temperatures during heatwaves, the spokesperson advised.
“The HPRA advises healthcare professionals to refer to the approved product information for individual medicines and to guidance issued by relevant public health authorities regarding the management of heat-related health risks.”
A spokesperson for the Pharmaceutical Society of Ireland (PSI) highlighted regulations and guidelines already in place to ensure medications are stored correctly, including guidelines on the storage of medicinal products in pharmacies and guidelines to support medicine therapy review, counselling and prescription extension.
