Drug Class Description

Generic Name

Drug Description

Presentation

Indications

Adult Dosage

The recommended dose of orlistat is one 120 mg capsule taken with water immediately before, during or up to one hour after each main meal. If a meal is missed or contains no fat, the dose of orlistat should be omitted.

The patient should be on a nutritionally balanced, mildly hypocaloric diet that contains approximately 30 % of calories from fat. It is recommended that the diet should be rich in fruit and vegetables. The daily intake of fat, carbohydrate and protein should be distributed over three main meals.

Doses of orlistat above 120 mg three times daily have not been shown to provide additional benefit.

The effect of orlistat results in an increase in faecal fat as early as 24 to 48 hours after dosing. Upon discontinuation of therapy, faecal fat content usually returns to pre-treatment levels, within 48 to 72 hours.

Special populations

The effect of orlistat in patients with hepatic and/or renal impairment, children and elderly patients has not been studied.

There is no relevant indication for use of Xenical in children.

Child Dosage

Contra Indications

• Hypersensitivity to the active substance or to any of the excipients.
• Chronic malabsorption syndrome.
• Cholestasis.
• Breast-feeding.

Special Precautions

In clinical trials, the decrease in bodyweight with orlistat treatment was less in type II diabetic patients than in non-diabetic patients. Antidiabetic medicinal product treatment may have to be closely monitored when taking orlistat.

Co-administration of orlistat with ciclosporin is not recommended.

Patients should be advised to adhere to the dietary recommendations they are given.

The possibility of experiencing gastrointestinal adverse reactions may increase when orlistat is taken with a diet high in fat (e.g. in a 2000 kcal/day diet, > 30 % of calories from fat equates to > 67 g of fat). The daily intake of fat should be distributed over three main meals. If orlistat is taken with a meal very high in fat, the possibility of gastrointestinal adverse reactions may increase.

Cases of rectal bleeding have been reported with Xenical. Prescribers should investigate further in case of severe and/or persistent symptoms.

The use of an additional contraceptive method is recommended to prevent possible failure of oral contraception that could occur in case of severe diarrhoea.

Coagulation parameters should be monitored in patients treated with concomitant oral anticoagulants.

Interactions

Ciclosporin

A decrease in ciclosporin plasma levels has been observed in a drug-drug-interaction study and also reported in several cases, when orlistat was administered concomitantly. This can lead to a decrease of immunosuppressive efficacy. Therefore the combination is not recommended. However, if such concomitant use is unavoidable, more frequent monitoring of ciclosporin blood levels should be performed both after addition of orlistat and upon discontinuation of orlistat in ciclosporin treated patients. Ciclosporin blood levels should be monitored until stabilised.

Acarbose

In the absence of pharmacokinetic interaction studies, the concomitant administration of orlistat with acarbose should be avoided.

Oral anticoagulants

When warfarin or other anticoagulants are given in combination with orlistat, international normalised ratio (INR) values should be monitored.

Fat soluble vitamins

Treatment with orlistat may potentially impair the absorption of fat-soluble vitamins (A, D, E and K).

The vast majority of patients receiving up to four full years of treatment with orlistat in clinical studies had vitamin A, D, E and K and beta-carotene levels that stayed within normal range. In order to ensure adequate nutrition, patients on a weight control diet should be advised to have a diet rich in fruit and vegetables and use of a multivitamin supplement could be considered. If a multivitamin supplement is recommended, it should be taken at least two hours after the administration of orlistat or at bedtime.

Amiodarone

A small decrease in plasma levels of amiodarone, when given as a single dose, has been observed in a limited number of healthy volunteers who received orlistat concomitantly; in patients receiving amiodarone treatment, the clinical relevance of this effect remains unknown. However, in patients receiving concomitant amiodarone treatment, reinforcement of clinical and ECG monitoring is warranted.

 Lack of interactions

No interactions with amitriptyline, atorvastatin, biguanides, digoxin, fibrates, fluoxetine, losartan, phenytoin, phentermine, pravastatin, nifedipine Gastrointestinal Therapeutic System (GITS), nifedipine slow release, sibutramine or alcohol have been observed. The absence of these interactions has been demonstrated in specific drug-drug-interaction studies.

The absence of an interaction between oral contraceptives and orlistat has been demonstrated in specific drug-drug interaction studies. However, orlistat may indirectly reduce the availability of oral contraceptives and lead to unexpected pregnancies in some individual cases. An additional contraceptive method is recommended in case of severe diarrhoea.

Adverse Reactions

Adverse reactions to orlistat are largely gastrointestinal in nature. The incidence of adverse events decreased with prolonged use of orlistat.

Adverse events are listed below by system organ class and frequency. Frequencies are defined as: very common (1/10), common (1/100 to <1/10), uncommon (1/1,000 to <1/100), rare (1/10,000 to <1/1,000) and very rare (<1/10,000) including isolated reports.

Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness.

The following table of undesirable effects (first year of treatment) is based on adverse events that occurred at a frequency of > 2 % and with an incidence 1 % above placebo in clinical trials of 1 and 2 years duration:

* only unique treatment adverse events that occurred at a frequency of > 2 % and with an incidence 1 % above placebo in obese type 2 diabetic patients.

In a 4 year clinical trial, the general pattern of adverse event distribution was similar to that reported for the 1 and 2 year studies with the total incidence of gastrointestinal related adverse events occurring in year 1 decreasing year on year over the four year period.

The following table of undesirable effects is based on post-marketing spontaneous reports, and therefore the frequency remains unknown:

Manufacturer

Drug Availability

Updated