The medications shown below make you more sensitive to heat-related illness.
• Consult your pharmacist or doctor if you think that you may be taking one of these drugs.
• Discuss any possible side-effects with your doctor or pharmacist.
• Never stop taking a drug without first consulting your doctor.
1. Sedatives (usually prescribed for problems affecting mental health)
e.g. phenothiazines, butyrophenones, thioxanthenes
These drugs reduce the ability of the body to deal with heat and reduce systolic blood pressure.
2. Diuretics (water pills)
e.g. bumetanide, furosemide
These drugs can lead to dehydration and reduce blood pressure.
3. Beta-blockers
e.g. atenolol, propranolol
Decreased sweating, reduced blood pressure, increased risk of fainting falls.
4. Calcium channel blockers
e.g. Amlodipine, nifedipine
Decreased blood pressure, increased risk of fainting and falls, electrolyte imbalance.
5. Anti-cholinergic drugs
e.g. Antidepressants like amitriptyline, imipramine, paroxetine, clomipramine
e.g. Antihistamines like diphenhydramine, chlorpheniramine, hydroxyzine.
e.g. Incontinence drugs like oxybutynin
e.g. Antipsychotic drugs like olanzapine, quetiapine
These drugs reduce sweating and can cause heat exhaustion and heat stroke. While taking one of these drugs, it is important not to become overheated during exercise, hot baths and other activities.
6. Anti-anginals
e.g. Glyceryl trinitrate, isosorbide mononitrate.
Worsen low blood pressure
7. Mood stabilizer antipsychotics
e.g. lithium, haloperidol, olanzapine, quetiapine, risperidone
These drugs change the ability of the body to sense that you are too hot and the way the body deals with heat by reducing the ability to sweat. If you become dehydrated, the levels in the body of the drug, especially lithium, will increase and cause lithium, will increase and cause lithium toxicity. This can result in serious complications including death.
8. Selective Serotonin Reuptake Inhibitors (SSRI) like fluoxetine and sertraline, and Serotonin and Norepinephrine Reuptake Inhibitors (SNRI) like duloxetine and venlafaxine.
These lead to increased sweating.
9. Tricyclic antidepressants (TCAS)
e.g. amitriptyline, clomipramine
Decreased sweating
10. Antiseizure medications
e.g. Topiramate, Oxcarbazepine, Carbamazepine
Decreased sweating, increased sweating and urination, dizziness and weakness, especially after increased dose.
For heat and health advice, call 21 231 231.
Call the Emergency Number 112 in cases of heat stroke (seizures, agitation, lethargy, rapid pulse, rapid shallow breathing).