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Pharmacology for Nurses

32.3 Lipase Inhibitors

Pharmacology for Nurses32.3 Lipase Inhibitors

Learning Outcomes

By the end of this section, you should be able to:

  • 32.3.1 Identify the characteristics of lipase inhibitor drugs used for weight management.
  • 32.3.2 Explain the indications, actions, adverse reactions, and interactions of lipase inhibitor drugs used for weight management.
  • 32.3.3 Describe nursing implications of lipase inhibitor drugs used for weight management.
  • 32.3.4 Explain the client education related to lipase inhibitor drugs used for weight management.

Lipase is a digestive enzyme that enables the body to digest and systemically absorb dietary fat. Lipase inhibitors bind to gastric and pancreatic lipases in the intestine. This prevents hydrolysis of dietary triglycerides into monoglycerides and fatty acids and the absorption of dietary fat. Currently, orlistat is the only one drug approved by the FDA as a lipase inhibitor (Yip & Ambizas, 2019).


Orlistat (Alli, Xenical) is a nonsystemic gastric lipase inhibitor that reduces intestinal absorption of dietary fat by approximately 30%. Orlistat binds to lipases, reducing absorption of dietary fat while also demonstrating the ability to lower total cholesterol, low-density lipoproteins, fasting glucose, and insulin concentrations. Additionally, client blood pressure measurements often improve (Sahebkar et al., 2018).

Orlistat is available as an oral capsule. Alli is available over the counter, whereas Xenical is available through a prescription. Capsules are taken up to three times a day, up to 1 hour before meals containing fat. Dietary fat is not absorbed systemically and is eliminated in feces.

Adverse Effects and Contraindications

Orlistat is not systemically absorbed, so the most common side effects are gastrointestinal: flatus, abdominal pain/discomfort, nausea, oily rectal discharge, fecal urgency, diarrhea, and fatty/oily stool. The adverse GI effects often subside within 4 weeks.

Orlistat is contraindicated in clients with hypersensitivity to the drug. It is also contraindicated in conditions such as gallbladder disease, cholestasis, malabsorption X drug syndrome, hypothyroidism, anorexia/bulimia nervosa, and organic causes of obesity. Orlistat is contraindicated in pregnant clients. It should be used cautiously with gastrointestinal diseases, nephrolithiasis, hyperoxaluria, and known dietary deficiencies of vitamins A, D, E, and K. Providers should exercise caution in older adults, lactating clients, and children under age 12.

Table 32.3 is a drug prototype table for lipase inhibitors featuring orlistat. It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.

Drug Class
Lipase inhibitor

Mechanism of Action
Reduces pancreatic and gastric lipase, thereby reducing absorption of fat in the GI system
Drug Dosage
One 120 mg capsule with each fat-containing meal (3 times per day).
Overweight and obesity

Therapeutic Effects
Reduces overall weight
Reduces GI absorption of dietary fat
Drug Interactions
Vitamins A, D, E, and K
HIV medications
Adverse Effects
Oily rectal discharge
Fecal urgency
Fatty stool
Hypersensitivity to drug
Malabsorption syndrome
Gallbladder disease

GI disorders
Vitamin deficiencies, especially A, D, E, and K
Children under age 12
Table 32.3 Drug Prototype Table: Orlistat (source:

Nursing Implications

The nurse should do the following for clients who are taking orlistat:

  • Consistently monitor the client’s weight, blood pressure, and serum lab values associated with obesity (e.g., lipids, glucose, and hepatic function tests).
  • Monitor clients with diabetes closely for hypoglycemia and/or the need for medication reduction or elimination. With weight loss, a client’s need for medications to treat diabetes may be reduced or eliminated.
  • Monitor clients with hypertension closely. With weight loss, a client’s need for medications to treat hypertension may be reduced or eliminated.
  • Monitor client’s weight every 3 months for dosage changes as needed.
  • Provide client teaching regarding the drug and when to call the health care provider. See below for client teaching guidelines.

Client Teaching Guidelines

The client taking orlistat should:

  • Distribute daily fat intake evenly across all three meals.
  • Be educated to supplement with a multivitamin that also contains vitamins A, D, E, and K because lipase inhibitors may prevent absorption of fat-soluble vitamins. Vitamin supplements should be taken 2 hours before or after taking a lipase inhibitor.
  • If taking levothyroxine concurrently, take orlistat 4 hours before or 4 hours after levothyroxine to avoid reducing the serum availability of levothyroxine.
  • Report low blood glucose levels to their health care provider because their medication may need to be readjusted or eliminated with weight loss.

The client taking orlistat should not:

  • Eat very high-fat meals, to minimize uncomfortable GI effects.

Nonpharmacological Lipase Inhibitors

Nonpharmacological natural lipase inhibitors are present in various foods and supplements. Ox bile supplements have lipase inhibitor activity and are taken in much the same way as orlistat. Although ox bile supplements are considered safe, they may cause uncomfortable GI symptoms and deficiencies in fat-soluble vitamins (A, D, E, K). Ox bile supplements have been used for centuries in Eastern medicine to support various GI symptoms.

Less-invasive natural lipase inhibitors include caffeine, green coffee bean extract, tea (especially green tea), panax ginseng, soybeans, apples, grapevines, yerba mate, mulberry extract, and peanuts. These food items and supplements may contain several natural lipase inhibitors such as flavonoids, lactones, and polyphenols. However, any weight-loss supplements should only be used under the guidance of a weight-management health care professional.

Special Considerations

Losing Weight

Finding a health care professional with experience in weight loss improves a person’s long-term weight-loss and management success. Different modalities work for different clients. An experienced weight-loss health care professional can develop an individualized weight-loss plan that includes a foundation of meal planning and exercise.

(Source: Perrault, 2022)


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