Medications That are Associated with Weight Gain

The following medications are commonly associated with weight gain

• Antipsychotics. Olanzapine, Clozapine, Risperidone, Quetiapine

• Mood stabilisers. Lithium, Sodium valproate

• Tricyclic antidepressants. Amitriptyline, Nortriptyline

• SSRIs. Citalopram. Mirtazapine

• Medications for diabetes, such as insulin and sulfonylureas

• Oral corticosteroids

• Beta-blockers

• Antiepileptic medications (also used for neuropathic pain), e.g. gabapentin/pregabalin

Most antidepressants contribute to some weight gain, with fluoxetine, venlafaxine deemed low risk. Bupropion is a rare SSRI that actually promotes weight loss but is not usually used as a first-line treatment choice for depression. 

If you are concerned about your weight, you may want to weigh up the pros/cons of taking these medications and have a discussion with your doctor. 

As a GP, you may employ the following strategies to mitigate weight gain of above medications. 

• Try and add more novel anti-diabetic medications as part of the patient’s treatment plan e.g. add SGLT-2 inhibitors/GLP-1 RAs and reduce/remove insulin use

• Consider more weight neutral treatment options e.g. fluoxetine, venlafaxine, aripiprazole, topiramate, lamotrigine

• Avoid off-label use of atypical antipsychotics

• Consider off-label use of metformin for patients taking long-term antipsychotics, particularly those of a later generation. Several meta-analyses of RCTs in patients with psychotic disorders show the benefit of metformin as a safe and effective intervention leading to modest weight loss and improved lipid and insulin sensitivity.