Every medication has potential side effects and risks, but some drugs can make summer heat downright dangerous. Certain classes of medications affect the body’s ability to regulate its internal temperature.
Some medications, such as anticholinergic, inhibit perspiration so the body can’t cool itself off. Diuretics cause the body to eliminate water through urination, but that promotes dehydration which can lead to overheating. Other medications constrict blood vessels… or reduce the force of heart beats… or slightly raise metabolism. Different drugs, different effects, but with all with a common side effect: When the mercury rises outdoors, the body has a more difficult time staying cool.
If you are taking one or more of the following medications, you may not be able to spend as much time in the heat as you used to, and you will have to watch for early signs of heat illness, including dizziness, nausea, muscle cramps, fatigue, headache, or fainting. Extreme heat illness can cause vomiting, difficulty breathing, hallucinations, confusion, disorientation, seizures, coma, or even death.
Please note: This list is not inclusive. If you have any question about your medications or their potential side effects, talk with your doctor.
Drugs that May Increase the Risk of Heat Illness
Cold & Allergy Medications; Antihistamines
- pseudoephedrine (Sudafed; Cenafed; many others)
- chlorpheniramine (Chlor-Trimeton; Teldrin; many others)
- diphenhydramine (Benadryl; Tusstat; Tuxadryl)
- hydroxyzine (Atarax; Vistaril; Vistazine)
High Blood Pressure Medications
- atenolol (Tenormin)
- carvedilol (Coreg)
- labetalol (Normodyne; Trandate)
- lisinopril (Prinivil; Prinzide; Zestril)
- metoprolol (Lopressor; Toprol)
- propranolol (Inderal)
Diuretics
- bumetanide – Bumex
- furosemide (Lasix)
- hydrochlorothiazide (Hydrodiuril; HCTZ)
- indapamide (Lozol)
- triamterene (Dyrenium; Dyazide; Maxzide)
Tricyclic antidepressants
- amitriptyline (Elavil)
- amoxapine (Asendin)
- chlordiazepoxide (Librium; Libritabs; Mitran)
- clomipramine – Anafranil
- desipramine – Norpramin
- doxepin – Sinequan
- imipramine – Tofranil
- nortriptyline – Pamelor, Aventyl
- trimepramine (Surmontil)
Parkinson’s Disease Medications
- benztropine (Cogentin)
- levodopa (Larodopa; L-dopa)
- trihexyphenidyl (Artane; Trihexy)
Anticholinergics
- diphenoxylate with atropine (Lomotil; Lomocot; others)
- flavoxate (Urispas)
- hyocyamine (Anaspaz; Cytospaz; Gastrosed; Levbid; others)
- oxybutynin (Ditropan; Oxytrol)
- propantheline (Pro-Banthine)
Psychotropic medications
- chlorpromazine (Thorazine)
- haloperidol (Haldol)
- lithium (Lithobid; Eskalith; Lithotabs)
- prochlorperazine (Compazine)
- promethazine (Phenergan)
- quetiapine – Seroquel
- risperidone (Risperdal)
Amphetamines & similar drugs
- amphetamine (Adderall)
- dextroamphetamine (Adderall)
- methylphenidate (Ritalin; Concerta)
- phentermine (Adipex-P; Ionamin; Fro-Fast SA)
