Clinical Practice Guidelines

Bridging the Gap: Bariatric Pharmacy Service

Innovative Practice
Bridging the Gap: Bariatric Pharmacy Service at OSF St Francis Medical Center
by Bridget Mattson, PharmD; Rachael Carrasca, PharmD; Jennifer Ellison, PharmD, BCPS

With an estimated 66 percent of adults considered either overweight or obese, obesity is a significant health issue in the United States. Risks of comorbidities such as heart disease, diabetes, stroke, and cancer are increased in obese patients. Obesity related US healthcare costs run an estimated $117 billion annually.1 Due to the risks and costs associated with obesity, bariatric surgery is becoming more common in the US, with an estimated 177,600 procedures performed in 2006.2

Bariatric surgery consists of either restrictive or restrictive/malabsorptive procedures.3,4 Restrictive procedures include lap band surgery, which involves the placement of a silicone band around the upper end of the stomach, creating a small gastric pouch with a narrow opening into the stomach. By decreasing food consumption, slowing gastric emptying, and prolonging feelings of satiety, weight loss occurs. Combination restrictive/malabsorptive procedures include Roux-en-y (RNY) and biliopancreatic diversion with duodenal switch (BPD-DS). With RNY, the surgeon creates a small pouch and attaches a Y-shaped section of the small intestine to this pouch, bypassing a large section of the large intestine. BPD-DS is similar to RNY except that the surgeon narrows the stomach into a sleeve instead of creating a pouch; the final section of the small intestine is attached to the sleeve. These combination strategies not only prolong satiety by decreasing the stomach volume, but also allow for fewer calories to be absorbed by decreasing the length of the small intestine.

While bariatric surgery is effective at treating obesity, it is not without complications. Nutrient deficiencies have been reported with the restrictive procedure but are especially common with combination bariatric surgeries. Nutrients most likely to be affected by bariatric surgery include3,4:

  • Vitamins A,D,E, and K
  • Calcium
  • Iron
  • Cyanocobalamin
  • Folate
  • Thiamine

Bariatric surgeries can dramatically affect drug absorption by significantly decreasing the size of the small intestine. Absorption of extended release drug formulations is particularly affected. Patient weight loss following bariatric surgery may necessitate dosing modifications of drugs such as insulin.

Description of Bariatric Program

The OSF Surgical Weight Loss Center of Excellence (COE) is a comprehensive team of healthcare professionals including surgeons, nurses, dieticians, exercise specialists, psychologists, a bariatric advocate and a pharmacist. The team meets monthly to continually improve all aspects of the bariatric surgery process. This program is certified as a Bariatric Surgery Center of Excellence by the American Society for Metabolic and Bariatric Surgery (ASMBS) based on quality care and maintenance of excellent short and long term outcomes.

Pharmacy's Role in Bariatric Program

A missed opportunity for pharmacy involvement was recognized by the pharmacist after attending the January 2007 meeting of the OSF Surgical Weight Loss COE. To determine which areas Pharmacy could impact and how to achieve those goals, data was collected for one month by a decentralized pharmacist. Data included the number of medication reconciliation discrepancies, medications taken, recommendations made to current drug therapy (e.g., drug formulation changes, held and discontinued medications, etc.), acceptance of recommendations, time spent on education and total interventions per patient. Discussion between the pharmacy department and the bariatric team led to the following goals being developed for optimal surgical outcomes:

  • Suspending medication therapies which could result in patient harm
  • Ensuring close monitoring of pertinent therapies
  • Providing optimal drug formulations for maximum absorption
  • Educating patients on special instructions of medications and providing guidance on acceptability of altering dosage forms
  • Recommending vitamin supplements
  • Serving as a resource for patients and healthcare professionals

On March 1st, 2007, the pharmacy began "bridging the gap" with education and medication changes needed for patients undergoing bariatric surgery. Later in the year, Pharmacy created a new position designated to pharmaceutical care of the bariatric population.

Outline of Pharmacy Processes

Medication Evaluation

After evaluating all prescription and OTC medications, a bariatric pharmacist sends the patient and the primary care physician (PCP) recommendations for changes that are necessary due to the specific type of surgery scheduled (Figure 1). The intent of involving the patient and PCP is to ensure a continuum of care. In order to streamline this process, an extended release autosubstitution list was developed to convert patients to immediate release formulations. (Figure 2).

Inpatient drug therapy monitoring

As a vital part of the inpatient interdisciplinary team, the bariatric pharmacist continues to follow post op patients from admission until discharge along with the surgeons. The pharmacist assists the team in initiating and adjusting home medications based on patients' clinical status (Figure 3).

Medication education prior to discharge

Education consists of discussing how each medication will be taken after surgery, which medications will be held or avoided, and monitoring parameters for pertinent medications (Figure 4). Vitamin recommendations are also discussed. Pharmacy collaborated with dieticians to develop and implement lifelong vitamin supplementation specific to each type of surgery (Figure 5).

To help with education, all patients receive a business card with the OSF Pharmacy Bariatric phone number. This phone line was created to serve as a resource for both patients and health care professionals with questions regarding medications either pre- or post-surgery. To date, the Pharmacy Bariatric phone line has logged over 250 phone calls.

Follow-up call

During a postoperative follow-up phone call, patients are asked about pain control, vitamin compliance, blood pressure and blood glucose monitoring, along with questions from initial counseling.

Support Group Involvement

Since education is a key part in the success of the program, a bariatric pharmacist speaks at support group meetings on various medication topics.

Experience and Future Goals of the Bariatric Pharmacy Service

Since implementation of the program, bariatric pharmacists have logged approximately 2,200 interventions with an estimated cost savings/avoidance of over $315,000. Future goals of the pharmacy bariatric program include daily rounding with surgeons, developing specific bariatric surgery discharge forms, and providing education to other healthcare professionals regarding medication therapy.


Implementation of our bariatric pharmacy services has significantly improved patient care by reducing costs, improving medication therapy, and providing drug information to patients, caregivers and health care professionals.


  1. American Society for Metabolic & Bariatric Surgery. Obesity in America.
    Details (accessed 2009 Feb 16).
  2. American Society for Metabolic & Bariatric Surgery. Bariatric Surgical Society Takes on New Name, New Mission and New Surgery; Metabolic Surgery Expected to Play Bigger Role in Treating Type 2 Diabetes And Other Metabolic Diseases.
    Details (accessed 2009 Feb 16).
  3. Miller AD, Smith KM. Medication and nutrient administration considerations after bariatric surgery. Am J Health-Syst Pharm. 2006;63:1852-7.
  4. Malinowski SS. Nutritional and Metabolic Complications of Bariatric Surgery. Am J Med Sci. 2006;331(4):219-225.