• Which medications are contraindicated after gastric bypass?
• Which medications require different dosage forms (e.g. sustained release)?
• Which medications require different doses?
• Does it depend on the type of gastric bypass?

Obesity, defined as a body mass index of 30 or more, is rampant in North America. In fact, it is estimated that more than one-third of all adults in the United States and almost one-quarter of adults in Canada are obese. Obesity is associated with many life-threatening diseases including cardiovascular disease, stroke, type 2 diabetes, and hypertension. In addition, it has been associated with dyslipidemia, some types of cancer, obstructive sleep apnea, osteoarthritis, and some gastrointestinal diseases. Weight loss via bariatric surgery is becoming more common. The National Institutes of Health Consensus Development Conference on gastrointestinal surgery recommends that bariatric surgery be considered in patients with a body mass index of 40 or greater, or a body mass index of 35 or greater if high-risk conditions such as severe sleep apnea or severe diabetes are present. This article discusses medication considerations in patients who have had bariatric surgery.