Xenical

Xenical Medication Overview

Xenical, with its active ingredient orlistat, is a prescription medication that is used to help individuals lose weight and reduce the risk of regaining weight already lost. Xenical operates by inhibiting the absorption of fats from the diet, thereby reducing caloric intake.

Therapeutic Indications

Xenical is indicated for obesity management including weight loss and weight maintenance when used in conjunction with a reduced-calorie diet. It is also indicated to reduce the risk of weight regain after prior weight loss. Xenical is effective in long-term weight control (weight loss, weight maintenance, and prevention of weight regain). Treatment with Xenical is accompanied by a nutritionally balanced, calorically controlled diet that contains approximately 30% of calories from fat.

Pharmacodynamic Properties

Orlistat, the active component of Xenical, is a potent and long-lasting inhibitor of gastric and pancreatic lipases, enzymes necessary for the digestion of fats. By inhibiting these enzymes, orlistat prevents the hydrolysis of dietary fat into absorbable free fatty acids and monoglycerides, thus reducing caloric intake and controlling weight. Orlistat’s activity is exerted in the lumen of the stomach and small intestine.

Dosage and Administration

The recommended dose of Xenical is one 120-mg capsule three times a day with each main meal containing fat. The dose should be taken during or up to 1 hour after the meal. If a meal is missed or contains no fat, the dose of Xenical can be omitted. Because Xenical has been shown to reduce the absorption of some fat-soluble vitamins and beta-carotene, patients should be counseled to take a multivitamin containing fat-soluble vitamins to ensure adequate nutrition. The multivitamin should be administered once a day, at least 2 hours before or after the administration of Xenical, such as at bedtime.

Special Population Considerations

Care should be exercised when prescribing Xenical to pregnant women or nursing mothers. Additionally, the safety and efficacy of Xenical in pediatric patients below the age of 12 have not been established. In elderly patients, Xenical should be used with caution since weight loss is not generally recommended for this age group. Patients with renal and hepatic impairment should be evaluated before being prescribed Xenical.

Drug Interactions

Xenical may interact with other medications such as cyclosporine, levothyroxine, antiepileptic drugs, and antiretroviral drugs for HIV. Concomitant administration of Xenical with cyclosporine is not recommended. If it is deemed necessary, cyclosporine levels should be monitored closely, with dosage adjustments made accordingly. Xenical may impair the absorption of fat-soluble vitamins; therefore, supplementation may be necessary during treatment.

Pharmacokinetic Considerations

After oral dosing with Xenical, systemic absorption of orlistat is minimal. Following oral administration, the majority of the active ingredient is excreted unchanged in the feces within 24 to 48 hours. The plasma elimination half-life of orlistat is approximately 1 to 2 hours. Orlistat’s low systemic absorption minimizes the potential for drug interactions mediated by systemic rather than gastrointestinal mechanisms.

Adverse Reactions and Side Effects

The most common side effects associated with Xenical relate to the gastrointestinal system and include oily spotting, flatus with discharge, fecal urgency, fatty/oily stool, oily evacuation, increased defecation, and fecal incontinence. These symptoms are generally mild and transient, often occurring at the beginning of therapy, and are a consequence of the fat-blocking action of the medication. Patients should monitor for signs of increased hypothyroidism and decreased therapeutic effects of antiepileptic drugs.

Monitoring Parameters

Patients taking Xenical should be monitored for weight loss efficacy and potential adverse reactions. Regular assessments of renal and liver function tests are recommended. Those also taking cyclosporine must have their drug levels monitored more frequently. Monitoring of blood glucose levels is recommended for diabetic patients. It is also advisable to monitor vitamin and nutritional intake to ensure appropriate supplementation.

Influence on Ability to Drive or Operate Machinery

No studies on the effects on the ability to drive and use machines have been performed. However, given the pharmacologic profile of the drug, Xenical is unlikely to have an effect on these abilities.

Overdosage Management

In cases of overdose, patients should be observed for signs of more severe gastrointestinal symptoms. Although no specific information on Xenical overdose is available, no significant adverse effects have been reported in such circumstances. Treatment for overdose should be symptomatic and supportive.

Storage and Disposal

Xenical capsules should be stored at 25°C (77°F) in a tightly closed container away from moisture and heat. Excessive temperature excursions are permissible between 15°-30°C (59°-86°F). Any unused and expired medication should be disposed of in accordance with local requirements.

Patient Counseling Information

Patients should be counseled to adhere to a nutritionally balanced, reduced-calorie diet with around 30% of calories from fat. They should be advised on the potential for gastrointestinal side effects and measures to manage them. It’s important for patients to understand the importance of taking a multivitamin supplement at bedtime. Moreover, they must be informed on the necessity of monitoring their weight regularly and updating the healthcare provider on their progress or any concerns.