A 40-year-old female patient with a BMI of 35 has been prescribed orlistat as part of a comprehensive weight management plan. The patient is about to start taking orlistat and comes to the pharmacy for counseling.

PMH: obesity, hypertension, T2DM, HLDL

Home meds: Amlodipine 5 mg PO QD, lisinopril 20 mg PO QD, metformin 1000 mg PO BID, and atorvastatin 10 mg PO QD

Which of the following counseling points is most important for the pharmacist to discuss with the patient regarding proper administration?

A) Orlistat should be taken on an empty stomach for maximum effectiveness.

B) It's important to maintain a high-fat diet (50% of total kcal) while taking orlistat to enhance weight loss.

C) Orlistat should be taken with each meal that contains dietary fat or up to one hour after the meal.

D) Orlistat should be taken with a multivitamin containing fat soluble vitamins at any time of the day to ensure proper supplementation.

Answer with Rationale

Weight loss management is one of the most discussed topics in clinical practice. A number of newer therapeutics have been approved or likely to be soon approved for obesity. Orlistat (Xenical) was one of the first agents approved for this indication and even has an OTC version known as Alli. Because of its mechanism of action acting locally within the GI tract to inhibit absorption of dietary fats, there are specific administration directions that should be followed. 

A) Incorrect. Orlistat should be taken with meals that contain dietary fat or up to one hour after the meal. Taking it on an empty stomach is not recommended and may reduce its effectiveness.

B) Incorrect. When taking orlistat, it is advisable to follow a reduced-calorie, low-fat diet. A high-fat diet can lead to increased side effects, including gastrointestinal disturbances.

C) Correct. Taking orlistat with meals containing dietary fat or shortly after the meal is essential for the drug to work as intended. Orlistat reduces the absorption of dietary fat, which can aid in weight management.

D) Incorrect.  While taking orlistat, it's advisable to supplement with a multivitamin containing fat-soluble vitamins (A, D, E, and K) because the drug can affect their absorption. However, the multivitamin should be taken at least two hours before or after taking orlistat, generally at bedtime.

Generic/Brand: Lisinopril (Zestril), Amlodipine (Norvasc), Metformin (Glucophage), Atorvastatin (Lipitor)

NAPLEX Core Competencies covered: 

1.2 (From patients: treatment adherence, or medication-taking behavior)

2.2 (Brand/Generic, physical descriptions

5.5 (Instructions or techniques for drug administration)