How Medication is Absorbed Differently After Bariatric Surgery

If you’ve recently had bariatric surgery, you’ve probably noticed that your body metabolizes, or absorbs, medication differently.  This is because the changes made to your digestive system, which differ by procedure. There are two primary issues involved in how medication is metabolized in the body ─ drug solubility and surface area.

Drug solubility and surface area go hand in hand. Solubility refers to how fast medication enters your bloodstream, and surface area relates to the size of the area where the medication is initially absorbed. If medication is delivered intravenously, it enters the bloodstream and is absorbed immediately. If it’s taken orally, clinically referred to as extravascularly, it enters the stomach and disintegrates. From there it enters the small intestines, which is the primary location for medication absorption.

Gastric Band or Sleeve vs. Gastric Bypass

Patients who have either a gastric band or gastric sleeve procedure should be able to resume medication without absorptive issues. However, those electing to have gastric bypass surgery can have issues with absorption. This is due to the fact that the surface area of the small intestines has been reduced, so medication will pass through more rapidly.

Can Absorption with Gastric Bypass Surgery be Addressed?

It can, and the best way is to do so is to switch a capsule or liquid form medications. Liquid medication has the fastest absorption rate with capsules being the next fastest.  Because tablets tend to dissolve more slowly than capsules, they also take longer to be absorbed. So tablets will pass through the intestines before they have time to be fully absorbed.

Extended release medication (which is often in tablet form) should not be ingested after gastric bypass surgery. They are meant to be absorbed by the body over the course of several hours, so they’ll pass through the gastrointestinal tract before they can be fully absorbed.

Full Disclosure with your Gastric Bypass Surgeon

The list of medications is seemingly endless, so it’s very important to share prescriptions and over-the-counter medication use with your surgeon. Also, make sure to ask about vitamins and minerals; they come in a variety of forms, as well, so their absorption will be affected by gastric bypass surgery.

If you’re interested in learning more about how medication is metabolized after bariatric surgery, or if you are still considering weight-loss surgery, contact Dr. Malladi today. She’s a board-certified, minimally-invasive bariatric and general surgeon. She’s been included in D Magazine’s Best Doctors edition in each of the last five (5) years.