Nutrient Supplementation

After gastric bypass, patients are prone to deficiencies of the fat-soluble vitamins (A, D, E and K) and calcium. They also have an increased risk of anemia due to inadequate amounts of iron, vitamin B12 and folate. Because of these deficits, all gastric bypass patients should take a daily multivitamin and calcium supplements, and additional supplementation with iron, vitamin B12 and folate may be necessary.

Making the stomach smaller through bariatric surgery decreases gastric acid production, which affects the absorption of calcium and can increase the patient’s risk of osteoporosis. Calcium carbonate requires acid to be absorbed, but calcium citrate, which we recommend for supplementation, does not.

The duodenum is the primary site for absorption of iron and is bypassed in the Roux-en-Y procedure. Like calcium, iron requires acid to be absorbed, which is lacking in the small gastric pouch. Gastric bypass patients can take iron salts combined with ascorbic acid (vitamin C) to acidify the stomach and facilitate absorption.

Vitamin B12 absorption requires intrinsic factor, which is produced in the bypassed part of the stomach, as well as acid; a lack of these can lead to vitamin B12 deficiency and anemia. Appropriate supplementation can be achieved by taking an oral formulation (1000 µg daily) or monthly injections.

Medications and Marginal Ulcers

Non-steroidal anti-inflammatory medications (NSAIDs), such as Advil, Motrin, Aleve, Excedrin and Celebrex, are used primarily to treat inflammation, fever and mild to moderate pain from headaches, arthritis, sports injuries and menstrual cramps.

Taking NSAIDs after gastric bypass surgery significantly increases the risk of developing marginal ulcers at the connection between the stomach pouch and the Roux limb. Thus, gastric bypass patients should avoid these medications.

The same risk extends to the salicylates (i.e., aspirin), but the risks and benefits of daily aspirin therapy should be considered on an individual basis. Safer options for oral pain medications include acetaminophen and opioids (Percocet, Vicodin, Tylenol #3 and Tramadol).

Oral biphosphonates are another type of medication that may produce marginal ulcers in gastric bypass patients. These drugs inhibit the loss of bone mass associated with bone diseases like osteoporosis and Paget’s disease; commonly used biphosphonates include Actonel, Aredia, Boniva, Didronel, Fosamax, Reclast, Skelid and Zometa. However, there are alternative treatment options available, such as calcitonin salmon nasal spray, synthetic parathyroid hormone and Raloxifene.

Anti-acid medications (Nexium, Protonix or Prevacid) are prescribed to prevent ulcers in the gastric pouch. We recommend taking one of these for at least six months following any type of bariatric surgery.

NSAIDs After Weight Loss Surgery

Reduced Medication Effectiveness

The shorter intestinal length after gastric bypass or duodenal switch surgery can make extended-release drug preparations less effective. Some extended-release drugs include antidepressants (Wellbutrin XL), anxiolytics and sleep medications (Xanax XR), and anti-hypertensives (Toprol XL, Verapamil XL). Because these formulations are intended to be absorbed over 2-12 hours, the pills may pass through the gastrointestinal tract before absorption is complete.

This same principle also applies to delayed-release and enteric- or film-coated pills, which are coated with a material that prevents the medication from being released until the pill moves through the stomach to the small intestine. (Sometimes the abbreviation “EC? is added to the name of a drug to indicate that it is enteric-coated.) Immediate-release dosage forms should be substituted, although they may need to be taken more often.

Oral contraceptives are another type of medication that may not be absorbed as effectively after surgery; thus, non-hormonal barrier contraception is recommended to prevent unwanted pregnancy for women who have had gastric bypass or duodenal switch operations.

Diarrhea, Constipation and Gallstones

Some patients experience mild gastrointestinal problems after surgery. Imodium AD is safe and effective for post-operative diarrhea, and mild gas pains can be treated with Gas-X.

Since bariatric patients consume less food, smaller amounts of stool are formed, which can lead to constipation. Some people find that taking two or three tablespoons of milk of magnesia every few days helps. Drinking plenty of water is very important, and nothing works well for constipation if water intake is poor. It is not uncommon for bariatric patients to have a bowel movement every two to three days once it is regulated.

Patients who continue to experience constipation can take a fiber supplement, like Metamucil or Fibercon, once they are on the pureed diet. Colace, a stool softener, is sometimes necessary for patients on pain medication to prevent constipation. Some patients are given Reglan and Zofran for nausea and to assist with bowel movements.

Rapid weight loss after bariatric surgery predisposes patients to gallstones. If you still have your gallbladder and the pre-operative ultrasound did not show gallstones, you should take Actigall for six months post-operatively to prevent them from forming.

Can I Resume My Diabetic and Water Pills?

Patients are usually instructed to resume most of their pre-operative medications. Those who are on diabetic medications will need to monitor their blood sugar closely at home. Some patients’ blood sugar decreases very quickly after surgery (even before any weight loss), and they will need less of their diabetic medications. The same applies to insulin, which should be given when blood sugar is under strict control and under the supervision of an endocrinologist or primary care physician.

Diuretics (water pills or Lasix) are frequently prescribed for patients with hypertension, edema and congestive heart failure. Many patients are instructed to hold off on resuming diuretics because it is important to avoid dehydration after gastric bypass surgery; this is usually decided on an individual basis.

Other antihypertensive medications are safe to use after gastric bypass. Typically, the dose decreases as patients lose weight and their hypertension improves. Consult your doctor to discuss changing doses and types of medication.

Should I Continue My Blood Thinner Medications?

Some patients take oral blood thinners like Coumadin for atrial fibrillation, blood clots and other cardiovascular conditions. Coumadin is typically stopped before surgery and replaced with heparin injections. Following surgery, Coumadin is gradually resumed, with heparin given at the same time to “bridge" its anticoagulant effect. After this temporary period, patients should continue Coumadin therapy under strict control of INR. No major changes in Coumadin dosing are required after gastric bypass.

My Pills Are Too Big!

The opening produced by Roux-en-Y surgery is about 1.5 cm wide, and gastric banding also produces a small opening. Some pills (such as calcium, multivitamins and iron) are quite big and cannot go through this small connection easily. We advise patients to take these pills one at a time throughout the day, if possible. Very large pills can be cut in half or crushed—but only if they are not time-release medications (i.e., diabetes pills). Ask your doctors if the pills they prescribe can be safely crushed.

Medications After Bariatric Surgery

About the Authors

Philip Schauer, MD, FACS is the Director of the Cleveland Clinic Bariatric and Metabolic Institute. He is the past president of the American Society for Bariatric Surgery (ASMBS) and Chair of ObesityWeek. Dr. Schauer's clinical interests include surgery for severe obesity, minimally invasive surgery (laparoscopic), and gastrointestinal surgery.

Tomasz Rogula, MD, PhD is a Staff Surgeon at the Bariatric and Metabolic Institute at Cleveland Clinic. He has trained in weight-loss surgery in the United States, Italy and France. In addition to bariatric surgery, his special interests include hernia repair, laparoscopic, robotic and gastrointestinal surgery.