Many commonly used medications may cause weight gain. The amount of weight gained may vary depending on the patient and type of medication.
Mechanisms for weight gain can be through:
- Stimulation of appetite
- Stimulation of fat storage
- Slowed metabolism
- Fluid retention
- Impaired exercise tolerance
In many cases, there might be an alternative medication with less effect on weight; in other cases the medications that cause weight gain may be preferable to alternatives. As many of these medications may be life-sustaining, patients should be advised against stopping any of these medications without first consulting their provider. The risks of stopping or changing medication should be balanced against the risks of obesity and related co-morbidities.
Knowing which medications may adversely affect weight will help both the patient and provider monitor any change in weight. It is important to note that not all patients respond similarly to these medications. It is also important to evaluate any supplements and over-the-counter medications the patient may be using as well.
The following classes of medications are associated with weight gain:
- Anti-depressants, anti-anxiety, mood stabilizers:
- Selective serotonin reuptake inhibitors (SSRIs): Paxil, Zoloft, Celexa, Prozac
- Older anti-depressants: Amitriptyline, Imipramine, Nortriptyline, Trazodone, Monoamine oxidase inhibitors (MAOIs)
- Olanzapine, Clozapine, Risperidone, Quetiapine, Aripiprazole, Haloperidol
- Diabetes medications:
- Insulin: Both short- and long-acting
- Sulfonylureas: Glimepiride, Glipizide, Glyburide
- Thiazolidinedione: Pioglitazone
- Other: Nateglinide, Repglinide
- Steroid hormones:
- Synthetic progestins: Medroxyprogesterone, Norethindrone, Levonorgestrel
- Contraceptives: Oral contraceptive pills, Nexplanon
- Corticosteroids: Prednisone, Methylprednisolone, Prednisolone
- Chemotherapy: Tamoxifen, Arimidex
- Anticonvulsants, anti-migraine, neuropathic pain:
- Gabapentin, Pregabalin, Valproic acid, Carbamazepine, Divalproex
- Opioids: All opioids may decreased metabolic rate and exercise tolerance
- Beta-blockers: Atenolol, Metoprolol, Propranolol, Acebutolol
- Alpha-blockers: Clonidine
- Calcium channel blockers: Nisoldipine
- Antihistamines: Diphenhydramine, Fexofenadine, Cetirizine, Ranitidine, Azelastine
- Hypnotics: Remeron, Zolpidem, Doxepin
If any of these medications need to be used and no alternative available, it is important to reassure the patient that weight loss and maintenance is still possible despite the effect of the medication.