Many medications change your body's ability to stay cool.

• Medications that lower the amount of blood pumped by the heart (cardiac output) so blood flow to the skin is less include:
  • Antispasmodics, such as Donnatal or Levsin.
  • Diuretics, such as Dyazide or Maxzide.
  • Beta-blockers, such as Inderal or Betapace.
  • Calcium channel blockers, such as Cardizem.
  • Anti-Parkinson medications, such as Sinemet.
• Medications that increase how much heat your body makes include:
  • Thyroid hormone, such as Synthroid, if you take too much.
  • Salicylates (aspirin products).
• Medications that change your sense of thirst in hot environments include:
  • Neuroleptics, such as Haldol or Prolixin.
  • Sedatives, such as Nembutal or Excedrin PM.
• Medications that lower your body's ability to keep the temperature in a normal range (thermoregulation) include:
  • Antihistamines, such as Benadryl and other nonprescription cold remedies.
  • Anticholinergics, such as Cystospaz.
  • Phenothiazines, such as chlorpromazine.
  • Benztropine mesylate.
  • Tricyclic antidepressants, such as amitriptyline or Sinequan.
  • Monoamine oxidase inhibitors (MAOIs), such as Furoxone or Nardil.

Alcohol and illegal drugs, such as methamphetamines, amphetamines, cocaine, heroin, PCP (phencyclidine hydrochloride), and LSD (lysergic acid diethylamide), also affect your ability to sense dehydration or heat-related symptoms. These substances also reduce your judgment about whether treatment is needed for a heat-related illness.