Weight gain or loss may also depend on medicines taken

Weight gain or loss may not always be caused by what you eat or how much you exercise. For some, it's the medicines you're taking.

Surprisingly, certain medicines can cause significant weight changes, which can be challenging for anyone wanting to shed pounds or maintain weight. The Harris County Hospital District's Drug Information Center wants everyone to know which medicines trigger gains or losses.

Weight side-effects are common in medicines used for diabetes, high-blood pressure and mental health conditions. Big gainers are likely for users of steroids for cancer treatment and women on birth control, while some antidepressants like Prozac® and Wellbutrin® are known for weight losses.

"Because of the stigma of weight gain, patients may tend to stop taking their medicines or decrease their dosage without talking to their physician," says Ryan Roux, PharmD, chief pharmacy officer, Harris County Hospital District. "Doing this is a bad thing. It can affect your health in a number of negative ways."

It's important for patients to tell their physicians about any weight changes. The weight gains or losses could mean reassessing types of medicine or dosages taken. Additionally, gaining weight could increase the chances of developing diabetes, hypertension or high cholesterol.

"Your healthcare provider should advise you of any potential side effects associated with your medication," says Andrea Henry, PharmD, formulary manager, Harris County Hospital District. "However, patients also should be actively involved in their treatment and become informed about their long-term medication use."

Here's a list of some common medications and their weight side effects listed by brand and generic name:

Diabetes:
Weight promoting
•Actos® (pioglitazone)
•Amaryl® (glimepiride)
•Insulins

Weight loss or weight neutral
•Byetta® (exenatide)
•Januvia® (sitagliptin)
•Symlin® (pramlintide)
•Metformin
•Precose® (acarbose)

Hypertension:
Weight promoting
•Lopressor ® (metoprolol)
•Tenormin® (atenolol)
•Inderal® (propranolol)
•Norvasc® (amlodipine)
•Clonidine

Antidepressants:
Weight promoting
•Paxil® (paroxetine)
•Zoloft® (sertraline)
•Amitripyline
•Remeron® (mirtazapine)

Weight loss or weight neutral
•Wellbutrin® (bupropion)
•Prozac® (fluoxetine)

Antipsychotic:
Weight promoting
•Clozaril® (clozapine)
•Zyprexa® (olanzapine)
•Risperdal® (risperidone
•Seroquel® (quetiapine)
•Lithium
•Valproic Acid
•Carbamazepine

Antiepileptic Drugs:
Weight promoting
•Carbamazapine
•Neurontin® (gabapentin)

Weight loss or weight neutral
•Lamictal® (lamotrigine)
•Topamax® (topiramate)
•Zonegran® (zonisamide)