Summer heat waves and the medications that increase your risk
Click here to download a printable version of this article.
By Camille Gagnon, Pharmacist, Assistant Director of the Canadian Medication Appropriateness and Deprescribing Network
For many Canadians, summer is synonymous with having fun in the sun. Unfortunately, over the past several years, extreme heat waves have become increasingly common. This not only makes summer less enjoyable but can affect your health. Heat and humidity can cause heat stroke, dehydration, dizziness and fainting, hospitalizations, and even death.
As you get older, it becomes harder for the body to adjust to changes in temperature. That’s why older adults are at greater risk during periods of extreme heat. Certain medical conditions more common in older adults, such as diabetes or Parkinson’s disease, can also make it harder for the body to adapt to heat.
Did you know? Some medications can increase your risk of heat stroke
Certain commonly used medications can make you more sensitive to the effects of heat. These medications can increase your risk of heat stroke and other heat illnesses. The more medications you take, the greater your risk.
Medications that can increase your risk
Below are several examples of medications that can impair your body’s ability to adapt to heat. Many of them are commonly used medications. Some are available with a prescription and others are available off the shelf in your pharmacy. Are you taking any of these medications?
Some medications impair the body’s ability to produce sweat, which is essential for cooling off when it’s hot out. For example:
Beta blockers (e.g. metoprolol or bisoprolol), which are medications used for certain heart conditions and for treating high blood pressure.
Decongestants such as pseudoephedrine, an active ingredient in cold medications that are available off the shelf.
Anticholinergic medications, which include some off-the-shelf allergy medications (e.g. diphenhydramine or Benadryl®), off-the-shelf sleeping pills (e.g. Nytol®), medications used to treat urinary incontinence (e.g. oxybutynine), and some antidepressants (e.g. amitriptyline or nortriptyline).
Click here to learn more about anticholinergic medications.
Some medications can make you dehydrated. For example:
Diuretics (e.g. hydrochlorothiazide or furosemide), laxatives (e.g. Senokot®) or some diabetes medications (e.g. Invokana® or Jardiance®), which increase the elimination of bodily fluids through urine or stool.
Some antidepressants (e.g. fluoxetine or venlafaxine) cause excessive sweating, which can lead to dehydration.
Some medications can increase your body temperature. For example:
Antipsychotic medications, such as olanzapine or quetiapine.
Stimulant medications for attention disorders, such as Ritalin® or Adderall®.
Some medications can make you drowsy, reduce your ability to concentrate, and slow your reaction time. This can impair your ability to adopt safe behaviours in period of extreme heat, such as drinking water or staying cool. For example:
Some medications can become toxic to the body and kidneys if you become dehydrated from the heat:
Anti-inflammatory medications (e.g. ibuprofen or Advil®, naproxen or Aleve®).
Blood thinners, which are used to prevent blood clots.
Medications for high blood pressure.
Various medications used to treat diabetes, including metformin.
Lithium, for bipolar disorder.
What can you do to prevent heat stroke and protect your health this summer?
If you take medications, especially any of those identified in this article, it’s particularly important to take action and prepare for the heat this summer. Here are 3 things you can do:
Protect yourself from extreme heat and stay hydrated, as per your health care professional’s recommendations. Visit this Government of Canada webpage to find out how to stay cool and hydrated during periods of extreme heat, and what to do in case of heat stroke.
Complete a thorough review of all your medications with your doctor, pharmacist or nurse. Make an appointment specifically for a medication review. Together with your health care professional, you can identify the medications that increase your risk of heat illnesses, including heat stroke and dehydration. You may then decide to put in place an action plan to reduce your risk. Don’t forget that medications that you can buy off the shelf can cause harmful effects too.
Do not hesitate to ask your health care professional the following question: “Do I still need this medication?” — The answer might surprise you! Even if it is not possible to stop a given medication, reducing the dose could decrease your risk of harm. For example, gradually reducing the dose of your sleeping pill could help you stay more alert, for a safer and healthier summer. If a medication is stopped or reduced, ensure that a follow-up plan is put in place with your health care provider.
The author
Camille Gagnon is the Assistant Director of the Canadian Medication Appropriateness and Deprescribing Network. Camille is a clinical pharmacist with experience in clinical program management, community pharmacy, teaching and pharmacogeriatrics.
The views expressed herein do not necessarily represent the views of Health Canada.
Doctor, do I really need an antibiotic?
What is antimicrobial resistance and why is it important?
When antibiotics no longer work to kill bacteria, this is called antibiotic or antimicrobial resistance. This means that infections caused by certain types of bacteria can become difficult or impossible to treat with the antibiotics we have now. Read more…
By Janet Currie and Johanna Trimble
Click here to download a printable version of this article
What is antimicrobial resistance and why is it important?
When antibiotics no longer work to kill bacteria, this is called antibiotic or antimicrobial resistance. This means that infections caused by certain types of bacteria can become difficult or impossible to treat with the antibiotics we have now. For example, there is growing evidence that urinary tract infections are becoming increasingly resistant to the antibiotics that, for generations, easily and quickly cured them. As another example, some types of tuberculosis have become resistant to antibiotics and are becoming deadlier, just like they were before antibiotics were discovered.
In Canada, over a quarter of bacterial infections are now resistant to antibiotics that once cured them (1). In 2018, experts estimated that 15 Canadians died every day as a direct result of antimicrobial resistance (1). According to the World Health Organization, antimicrobial resistance is one of the ten most serious public health problems of our time (2). Antimicrobial resistance has been made worse because of a decline in the development of new antibiotics over the past decades, especially those that target the most resistant bacteria.
Why should older Canadians be concerned about antibiotic resistance?
Canadians aged 60 and over are prescribed antibiotics 1.5 times more often than any other age group (3). Older people may have weaker immune systems, making them more vulnerable to bacterial infections. Furthermore, older Canadians living in long-term care or assisted living facilities or who are admitted to hospitals may be more at risk of being exposed to “superbugs” like C. difficile. C. difficile can cause a life threatening diarrheal illness, especially among those who have compromised immune systems or who have recently used antibiotics. C. difficile is now resistant to most antibiotics.
What causes antibiotic resistance?
Using antibiotics when they are not needed or don’t work.
Antibiotics are often prescribed to treat illnesses not caused by bacteria. Colds and flu are caused by viruses and cannot be cured by antibiotics. Another example is when a lab test shows bacteria in the urine but there are no physical symptoms of a urinary tract infection, which is common in older adults. Giving antibiotics in this case can lead to overuse and antibiotic resistance.
Overusing broad spectrum antibiotics.
Broad-spectrum antibiotics are a type of antibiotic that kill many types of bacteria as opposed to only the specific bacteria causing the illness. For example, the overuse of broad-spectrum fluroquinolone antibiotics (drugs whose names end in “floxacin”, such as ciprofloxacin or Cipro®) contributes to antimicrobial resistance. Not to mention, fluroquinolones have a history of harmful side effects (4). Narrow-spectrum antibiotics, which focus on the specific bacteria causing the infection, should be used where possible. Sometimes, tests are needed to determine the type of bacteria involved.
Not using antibiotics as prescribed.
It is important to only use antibiotics that are prescribed for you and to take the dose as prescribed, even if the infection seems to be gone before the treatment is finished.
Global, poorly regulated antibiotic use.
Antibiotics are overused in agriculture as well as seafood and meat production. In some countries, they are available without a prescription, leading to overuse and contributing to resistance. Residue from human and animal antibiotic use contaminates our soil and water, another cause of antibiotic resistance.
What can you do to help reduce antibiotic resistance?
DON’T
Do not share or use leftover antibiotics.
Do not demand an antibiotic if your doctor, nurse, dentist or pharmacist says you don’t need one.
DO
Ask your doctor, nurse, dentist or pharmacist, “Do I really need an antibiotic?”
Follow your doctor, nurse, dentist or pharmacist’s advice if you are prescribed antibiotics.
Take all of the antibiotics as prescribed, even if you feel better before you are finished.
Avoid infections from bacteria:
Wash your hands regularly, especially after you use the bathroom and before eating.
Avoid close contact with sick people.
Keep your vaccines up to date.
Spread the word about the dangers of antibiotic resistance and how we must use antibiotics more wisely.
Always talk to your doctor, pharmacist or nurse before stopping or changing any medication.
References
1. Council of Canadian Academies. (2019). When Antibiotics Fail. The Expert Panel on the Potential Socio-Economic Impacts of Antimicrobial Resistance in Canada, Council of Canadian Academies. https://cca-reports.ca/wp-content/uploads/2018/10/When-Antibiotics-Fail-1.pdf
2. World Health Organization. (2021, November 17). Antimicrobial resistance. https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance
3. Public Health Agency of Canada. (2018, April 3). Prescribe antibiotics wisely (Clinical points). Government of Canada. https://www.canada.ca/en/public-health/services/publications/drugs-health-products/prescribe-antibiotics-wisely.html
4. Health Canada. (2017, January 23). Summary Safety Review - Fluoroquinolones - Assessing the potential risk of persistent and disabling side effects. Government of Canada. https://www.canada.ca/en/health-canada/services/drugs-health-products/medeffect-canada/safety-reviews/summary-safety-review-fluoroquinolones-assessing-potential-risk-persistent-disabling-effects.html
The authors
Janet Currie is a social worker who has been involved with patient and medication safety issues for over 17 years. She is particularly concerned about the safety and efficacy of psychiatric drugs and their impacts on seniors. She is a member of the core Executive of the Canadian Deprescribing Network, the past co-chair of the Canadian Women’s Health Network and was a two-term member of Health Canada’s Expert Advisory Committee on the Vigilance of Health Products. She owns and manages a website on psychiatric drug safety and has frequently testified to the Canadian Senate and the Parliamentary Standing Committee on Health on prescription drug surveillance and adverse drug effects. She is completing a Ph.D. on medication safety and off-label prescribing at UBC. Janet is Chair of the Patient Awareness Committee of the Canadian Medication Appropriateness and Deprescribing Network.
Johanna Trimble is a patient safety advocate and member of the BC Patient Voices Network. She is a member of the Geriatrics and Palliative Care Subcommittee of the Council on Health Promotion for Doctors of BC. As an honourary lecturer, she co-teaches first-year medical students at UBC in Community Geriatrics as well as pharmacy students on medication issues in Long Term Care. Johanna is an active member of the Patient Awareness Committee of the Canadian Medication Appropriateness and Deprescribing Network.