What is Xenical?
Xenical is a medicine used to help treat obesity, and should be taken while following a low calorie diet. The active ingredient is called Orlistat.
Effectiveness
Data from clinical trials showed that 37% of patients taking Xenical for 12 weeks lost at least 5% of their body weight, and 20% of patients taking it for a year lost at least 10% of their body weight. A study involving type 2 diabetics showed that 60% of patients lost at least 5% of their body weight after 12 weeks, and 41% lost at least 10% of their body weight after a year.
The effectiveness of Xenical is also dependent on patients adopting a diet plan which reduces the daily calorie intake.
Side effects
All medicines carry the risk of side effects, although not everybody will experience them. If you experience any side effects, tell your doctor or pharmacist as soon as you can. The majority of side effects experienced when taking Xenical are related to how it works in the digestive system.
Very common side effects include headaches, abdominal pain or discomfort, an urgent or increased need to open the bowels, flatulence with discharge, oily discharge, oily or fatty stools and liquid stools. Low blood sugar levels can be experienced by some people with type 2 diabetes, so diabetes treatments need to be carefully monitored.
How does Xenical work?
The active ingredient in Xenical is called Orlistat. It works by attaching itself to enzymes in your digestive system (known as lipases). Once attached it then stops the enzymes from breaking down approximately a third of the fat you eat during a meal. This fat is then excreted from the body.
This means that as your body is unable to take in some of the fat in the meal, it is increasing the effect of a calorie controlled diet.
How long does Xenical take to work?
Xenical works with each meal it’s taken with; so if you eat a meal that contains no fat (or if you miss a meal), there’s no need to take any Xenical. Always take Xenical as per your doctor’s instructions. You should aim to lose around 5% of your weight in the first 12 weeks.
How do you take Xenical?
Xenical should always be taken exactly as it’s been prescribed by your GP or pharmacist. It typically comes in capsule rather than pill form. The typical dosage of Xenical is one 120mg capsule taken with water either before, during or after each of the day’s three main meals. Xenical should be taken in conjunction with a calorie controlled balanced diet which is rich in fruit and vegetables. If you haven’t lost at least 5% of your body weight after taking Xenical for 12 weeks, your doctor will stop the treatment.
If you miss or forget to take Xenical, take it as soon as you remember as long as it’s within an hour of your last meal. If you’ve missed several doses, please speak to your doctor.
Who should use Xenical?
Xenical should not be used by everyone who wants to lose weight. It is only recommended in people over a certain body mass index (BMI). For a doctor to prescribe Xenical, they also need to be sure that you have tried changing your diet and increasing your physical activity levels first.
Doctors are expected to use the following guidelines when prescribing Xenical:
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Your BMI:
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Must be 30 or above; or
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Must be 28 or above, and you have a medical condition that would benefit from losing weight (such as diabetes or high blood pressure).
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You must lose at least 5% of your weight by three months from starting Xenical; if not, treatment with Xenical is not recommended and should be stopped.
Who should not use Xenical?
You should not take Xenical if you fit into one of the following categories:
- Pregnant or breastfeeding women.
- People under the age of 18 years.
- People who have a condition where food is not absorbed properly (a malabsorption syndrome).
- People with cholestasis. This is a condition where bile does not flow properly from the liver to the duodenum.
- People who have a history of Eating Disorders (anorexia/bulimia)
Xenical can also interfere with the absorption of various medicines and vitamins and affect the way that they work. For example, Xenical interferes with:
- Some treatments for HIV and AIDS.
- Ciclosporin.
- Acarbose.
- Levothyroxine.
- Amiodarone.
- Warfarin.
- Some treatments for epilepsy.
Always read the packet leaflet for a full list of cautions and of people who should not take Xenical.
Can I use Xenical with other medications?
Please inform your doctor or pharmacist if you are taking or have recently taken any other medicines, even those not prescribed. This is important as using more than one medicine at the same time can strengthen or weaken the effects of the medicines.
Xenical may modify the activity of:
- Anticoagulant drugs (e.g. warfarin). Your doctor may need to monitor your blood coagulation
- Ciclosporin. Co-administration with ciclosporin is not recommended. Your doctor may need to monitor your ciclosporin blood levels more frequently than usual
- Iodine salts and/or levothyroxine
- Cases of hypothyroidism and/or reduced control of hypothyroidism may occur
- Amiodarone. You may ask your doctor for advice
- Medicines to treat HIV
- Medicines for depression, psychiatric disorders or anxiousness
- When taking Xenical it is important:
- If you take the contraceptive pill and have severe diarrhoea you should use other methods of contraception in addition to the pill - for example, condoms.
- Tell your doctor or pharmacist about other medicines that you take, before starting on orlistat.
- Take a multivitamin supplement at bedtime - a time when you will not be taking orlistat - to help ensure adequate vitamin intake.
Xenical reduces the absorption of some fat soluble nutrients, particularly beta-carotene and vitamin E. You should therefore follow your doctor’s advice in taking a well balanced diet rich in fruit and vegetables. Your doctor may suggest you take a multivitamin supplement.
Xenical may unbalance an anticonvulsant treatment, by decreasing the absorption of antiepileptic drugs, thus leading to convulsions. Please contact your doctor if you think that the frequency and/or severity of the convulsions have changed when taking Xenical together with antiepileptic drugs.
Xenical is not recommended for people taking acarbose (an anti-diabetic drug used to treat type 2 diabetes mellitus).
Saxenda is another prescription only, daily injection weight loss medicine. Mysimba (naltrexone 8mg + bupropion 90mg) is a combination of two medicines which has been developed to encourage weight loss by reducing appetite. It is available in tablet form.
You can also buy Orlistat tablets online without a prescription as the same active ingredient in Xenical is also available at a lower strength in Alli, an over-the-counter medicine. You can purchase it from our sister company, ChemistDirect.