Heat and Sun Sensitivity and Psychiatric Medication

Photo courtesy of ground.zero via Flickr || Heat and sun sensitivity are pretty common side effects among psychiatric medication. Some drugs carry big warnings about these side effects and others don’t, depending on the severity of the reaction. Regardless though, heat and sun sensitivity can keep you downright miserable in the summer months even if they aren’t always dangerous.

How Do Medications Cause Sensitivity?

Sensitivity happens in a few ways. Some medications:

• react with the proteins in skin making it particularly sensitive to the sun
• prevent sweating meaning the body can’t cool itself properly
• cause profuse sweating and thus dehydration leading to sunstroke or heatstroke
• decrease blood flow to the skin preventing the body from cooling down
• increase muscle movements which increases body temperature

Which Drugs Cause Heat and Sun Sensitivity?

Well, many of them, both inside and outside of psychiatry, but there are a couple of note for people with bipolar disorder.

Topiramate (Topamax)

A report was just released about the dangers of using topiramate (an anticonvulsant sometimes used to treat bipolar) in extreme heat as it can exaggerate the body’s response to heat. The body may sweat profusely thus leading to dehydration and an increased risk for heat exhaustion or heatstroke wherein the body’s organs may malfunction.

Lithium

The dangers with lithium and dehydration due to sun exposure are well known and usually patients are told about them right away. This danger is particularly notable as it can raise lithium levels  in the blood and cause lithium toxicity. 

Other psychiatric drugs that often cause heat or sun sensitivity include:

• Carbamazepine (Tegretol): sun sensitivity definitely noted in the literature
• Divalproex (Depakote): sun sensitivity  noted as rare (less than 1 percent)
• most old antipsychotics (phenothiazines, particularly Chlorpromazine (Thorazine): noted for sun sensitivity
• some antidepressants: including bupropion (Welbutrin), sertraline (Zoloft), desipramine (Norpramin), imipramine (Tofranil), amitriptyline (Elavil), desyrel (Trazadone), tranylcypromine (Parnate), doxepin (Sinequan) and others  

See a more complete list of drugs here  and here.

Early Warning Signs of Heat Sensitivity

Early warning signs  of heat sensitivity include:

• weakness
• dizziness
• headache
• muscle cramps
• nausea
• vomiting
• body temperature between 100.4°F-104.9°F
• low blood pressure
• fast heartbeats

And while not officially listed, I find it incredibly hard to think and cognitively function in the heat (personally).

And, of course, sun sensitivity will result in a rash that often is similar to a sunburn.
If heat sensitivity progresses it can lead to:

• body temperature of more than 104.9°F
• confusion and coma
• throbbing headache
• unconsciousness
• red, hot, and dry skin without sweating

And in this case, emergency treatment should be sought immediately.

What to Do About Heat and Sun Sensitivity

Well, the simplest piece of advice I can give you is to stay cool and stay covered when you are outdoors. If you need to expose your skin to the sun, make sure to wear full-spectrum sunblock (blocks UVA-A and UVA-B rays) of a high sun protection factor (SPF). And, of course, talk to your doctor about your concerns.
Also:

• limit time in saunas or spas (which shouldn’t be hard because you probably won’t enjoy them anyway)
• drink plenty of water
• do not drink alcohol or caffeinated beverages
• avoid outdoor activities during the hottest part of the day
• shower, bathe or apply cool, wet cloths

In short, when it gets hot, stay the heck out of the heat and protect yourself if you do have to be in it. This is an excellent excuse for lemonade in the shade and that’s a side effect I can live with.