We use some essential cookies to make this website work.
We’d like to set additional cookies to understand how you use GOV.UK, remember your settings and improve government services.
We also use cookies set by other sites to help us deliver content from their services.
You can change your cookie settings at any time.
Find information and services
Search for a department and find out what the government is doing
Departments, agencies and public bodies
News stories, speeches, letters and notices
Detailed guidance, regulations and rules
Reports, analysis and official statistics
Consultations and strategy
Data, Freedom of Information releases and corporate reports
Initiate orlistat treatment only after careful consideration of the possible impact on efficacy of antiretroviral HIV medicines.
Article date: March 2014
Orlistat is indicated for weight loss in combination with a low-calorie, low-fat diet. It is available as 120 mg capsules under the brand name Xenical and as 60 mg capsules under the brand name alli. Xenical is only available with a prescription, whereas alli is available without a prescription under the supervision of a pharmacist.
Orlistat is a potent, specific, and long-acting inhibitor of gastrointestinal lipases which decreases the amount of fat absorbed from the diet.
On the basis of reports from literature[footnote 1] [footnote 2]and data obtained after licensing, orlistat may theoretically reduce the absorption of antiretroviral HIV medicines. This may be due to retention of lipophilic medicines in the gastrointestinal tract or reduced gastrointestinal tract transit time. This interaction could negatively affect the efficacy of antiretroviral HIV medications. Reports have been received of suspected interactions between orlistat and efavirenz, and between orlistat and lopinavir. However, the theoretical interaction mechanism described above could also apply to other antiretroviral medicines.
Advice for healthcare professionals:
de Truchis P et al. AIDS 2010; 24: 1235–36. ↩
Kent SJ. AIDS Res Hum Retroviruses 2012; 28: 961–62. ↩
Check what you need to do
Don’t include personal or financial information like your National Insurance number or credit card details.
To help us improve GOV.UK, we’d like to know more about your visit today. We’ll send you a link to a feedback form. It will take only 2 minutes to fill in. Don’t worry we won’t send you spam or share your email address with anyone.
