Developed in collaboration with CASA Medical.
The medications of the class “Glucagon-Like Peptide-1 receptor agonists” or GLP-1RAs are prescribed for the management of obesity. In NZ liraglutide and semaglutide are approved by Medsafe for weight management. Three GLP-1RAs have been approved by the Australian Therapeutic Goods Administration: semaglutide, liraglutide and tirzepatide. There are a number of brands and formulations of these agents. They all share the same mechanism of action and have similar effectiveness and side effect profiles.
This guideline refers to the use of GLP-1RAs for weight management. Please refer to the Diabetes CPG for information on the use of GLP-1RAs in the management of Diabetes.
GLP-1RAs work by regulating glucose and appetite. Glucose levels are regulated by stimulating natural insulin secretion when blood sugar is high. Appetite is regulated through actions on the way the brain perceives hunger and cravings, and the sense of satisfaction from eating.
Side effects are common but usually of mild severity. Most often people experience gastrointestinal side effects of nausea, vomiting, diarrhoea or constipation. In some cases these are severe enough for the person to be unable to perform their usual daily activities, so they are forced to reduce their dose or stop using the medication altogether. Rarely people can have problems relating to gall stones and the gall bladder system (gall stones, gall bladder inflammation or infection), or inflammation of the pancreas. Reports of mental health complications have not been confirmed by researchers. Low blood sugar is not of concern when the medication is used for weight management in people who are not also taking other medications for diabetes.
The aeromedical safety relevance of GLP-1RAs is related to the experience of acute and severe nausea, vomiting and diarrhoea, or pain related to biliary and pancreatic complications. Gastrointestinal symptoms are a common cause of in-flight impairment for pilots. If any of these are experienced, the license-holder must cease their aviation duties and seek advice from their treating doctor. Return to aviation duties will depend on the type and severity of the event.
The reduction in energy and nutritional intake associated with the effect of GLP-1RAs may also be safety relevant for aviation, and license-holders should be counselled and investigated accordingly. Consideration should be given to testing iron studies, vitamin D, calcium, B12 and folate. Loss of muscle mass and reduced bone density may also be an issue that becomes safety relevant in some operational situations.
For more information, see Medical Manual: Weight loss - GLP-1 medication.
