Is Your Medicine Causing Weight Gain?

You’ve been watching your diet and following your usual exercise routine. But your pants seem a little tight and, sure enough, the scale shows that you’ve gained five pounds in the past month.

What’s going on?

If you’re gaining weight for no reason or having trouble losing it, check the contents of your medicine cabinet. Experts don’t fully know why some drugs pack on pounds but your doctor may be able to switch you to a different class or lower dose of a drug. Here, some common weight-gain-causing meds and their smart swaps.

Drugs for: Depression

Could Cause Weight Gain: SSRIs such as paroxetine (Paxil, Pexeva), citalopram (Celexa)

Skinny Alternative: Bupropion (Wellbutrin, Aplenzin)

Expert Say: Some researchers believe SSRI-style drugs increase appetite. Antidepressants that affect dopamine, such as bupropion, may actually reduce hunger.

Drugs for: High blood pressure, coronary artery disease

Could Cause Weight Gain: Powerful beta-blockers such as metoprolol (Lopressor), atenolol (Tenormin)

Skinny Alternative: Mixed alphaand betablockers such as carvedilol (Coreg)

Experts Say: With the single-effect beta-blockers, it can be harder to lose weight, possibly because they reduce metabolic rate.

Drugs for: Allergies

Could Cause Weight Gain: The antihistamine diphenhydramine (Benadryl, Alka-Seltzer Plus Allergy)

Skinny Alternative: Antihistamines loratadine (Claritin), cetirizine (Zytrec)

Experts Say: The alternatives contain different, less potent active chemicals, decreasing the chances that the drugs will boost appetite.

Could Cause Weight Gain: Diphenhydramine (in over-thecounter brands Sominex, Unisom, Nytol)

Skinny Alternative: Zolpidem (in prescription Ambien).

Experts Say: Occasionally taking an over-the-counter sleep aid shouldn’t cause weight gain; for everynight help, consider switching to prescription.

Drugs for: Diabetes

Could cause weight gain: Rosiglitazone (Avandia), pioglitazone (Actos), glyburide (Diabeta, Glynase), glipizide (Glucotrol), insulin

Skinny alternatives: Metformin (Fortamet, Glucophage, Glucophage XR, Glumetza, Riomet), sitagliptin (Januvia), injectable GLP-1 drugs such as liraglutide (Victoza), exenatide (Byetta), pramlintide (Symlin)

Experts say: Even some doctors don’t realize that some popular classes of anti-diabetes drugs can lead to extra pounds—which can make diabetes worse.

Drugs for: Bipolar disorder or schizophrenia

Could cause weight gain: Olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal), clozapine (Clozaril, Fazaclo), lithium

Skinny alternative: Ziprasidone (Geodon)

Experts Say: Drugs for bipolar disorder, especially olanzapine, are notorious for often causing huge weight gains in a short amount of time. Ziprasidone operates differently and is not associated with weight gain.

Drugs for: Hormonal birth control

Could cause weight gain: High–dose progesterone formulations, such as medroxyprogesterone (Provera, Depo-Provera)

Skinny alternative: Low-dose progesterone hormonal birth control formulations

Experts say: Progestin hormones are so effective at causing weight gain that they’re often prescribed for that purpose in cancer and AIDS patients. One study found that women gained an average of six pounds during the first year on these medications.

Drugs for: Asthma, allergies, inflammation

Could cause weight gain: Oral corticosteroids, including prednisone

Skinny alternative: Inhaled corticosteroids

Experts Say: Taking corticosteroids orally affects the entire body, which is why pills are more likely to cause weight gain than the same medication inhaled straight into the lungs.