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Covid-19 (Coronavirus)

Information and guidance for public, NHSGGC staff, and community-based services.  Hospital visiting restrictions now in place.


What weight loss medications do you offer within the Weight Management Service?

Currently the only licensed drug for weight management is orlistat, brand name: Xenical.                                                                

When is medication offered?

The medication is offered to patients who have completed our 16-week lifestyle programme and have not achieved 5kg weight loss through lifestyle changes. The decision to try medication is discussed with the dietitian and the patient and an appropriate treatment plan is agreed. 

Who is it appropriate for?

Patients who struggle to follow a low fat diet and require additional help to lose weight. If a patient’s diet is not high in fat it is unlikely that this medication will improve weight loss.                                                                                                                                                                        

How does orlistat work?

Orlistat is a potent inhibitor of pancreatic and gastric lipases, the enzymes used to break down dietary fat. It works locally in the stomach and intestine to prevent absorption of approximately 30% of ingested fat from foods. The dosage is a 120 mg tablet and it is taken 3 x day within an hour of eating a meal. The medication is effective if taken as part of an overall plan of dietary and lifestyle changes to manage and lose weight.                    

What guidance is given to the patient about the drug?

Specific information includes how to identify the types of foods which are high in fat, label reading education so that high fat foods are avoided, ways to control food portion sizes and ideas on low fat snacks. We also support patients with meal ideas, advice on eating out, how to control cravings, how to deal with weight loss plateaus and how to avoid side effects of the medication. We stress to patients that the drug is an ‘adjunct’ to dietary and lifestyle changes, it will not be the ‘magic bullet’ to weight loss but can be of benefit if taken correctly with a healthy balanced diet.            

Who is responsible for prescribing?

The GP is responsible for prescribing the medication, however in Glasgow and Clyde NHS our local formulary advises that GP’s should prescribe orlistat only on the advice of SWMS as this ensures the most effective use of the medication and the best outcome for patients.            

Can a patient enter the service while already taking Orlistat?

Yes, this sometimes happens although not recommended and GP’s are discouraged from prescribing out with SWMS. The evidence suggests that  that patients are far more likely to be successful on Orlistat when they have the support of a structured weight management programme. (                                                                                                                                           

What monitoring is given?

SWMS is responsible for monitoring patients on Orlistat. This is carried out by monthly weight checks along with assessment of adherence to the drug through the group programme or through 1:1 sessions. All monitoring is in line with prescribing licence. If a patient fails to meet the weight loss criteria of 5% in 3 months the GP is advised to discontinue the medication.                                                                                                              

How do you feedback to GPs?

We provide an update on progress at assessment, at the end of each phase when recommending medication and then once again on completion of the programme. We may also contact a GP if weight gain of greater than 3kg occurs on medication or if there is failure to attend the group sessions. In these instances we would advise the drug be discontinued as the patient would not be receiving the recommended group intervention or weight monitoring support and the drug is therefore likely to be less effective.                                                                                              

How is the duration of treatment decided?

Our protocols in line with guidance and we recommend continuing treatment for longer than 3 months only if a patient has lost at least 5% of their initial body weight since starting drug treatment. Patients with Type 2 diabetes may be given a little longer as in some instances weight loss can be slower.


How long can I take Orlistat for?

The longest study published describing long-term Orlistat use is of 4 years duration although long term use of the drug is used mainly for weight maintenance rather than weight loss. If a patient is discharged from SWMS while still using Orlistat the monitoring is handed over to the patients GP.


Information on drug-nutrient interactions and side effects:

For patients vulnerable to vitamin D deficiency

We would recommend whilst on orlistat patients be tested for existing Vitamin D deficiency and then re-checked on an annual basis. 

Contra-indications to orlistat:

  • Chronic malabsorption syndrome
  • Cholestasis
  • Pregnancy
  • Breast-feeding.

Side effects of orlistat:

Side effects such as oily leakage, flatulence, faecal urgency, liquid or oily stools, faecal incontinence, abdominal distension and pain (gastro-intestinal effects) are usually minimised by reduced fat intake in meals and foods consumed.    .

Patients who experience these side effects usually have only one or two events during the early days or weeks of treatment. 

Please note in patients with Type 2 diabetes, close monitoring of diabetic control is required when Victoza® and Orlistat are co-prescribed.