Each week we will aim to bring out a concise email that provides 4-5 key pieces of information addressing a specific issue in clinical therapeutics.
This week: Drug-induced weight gain
Drug-induced weight gain is relatively common adverse effect associated with a range of treatments. As well as being associated with compromised adherence to treatment regimens, weight gain may be associated with serious metabolic consequences such as impaired glucose tolerance and hyperlipidaemia, and may ultimately increase the risk of cardiovascular disease and degenerative changes in joints such as the hip, knee and ankle.
- Psychotropic and anticonvulsant drugs are commonly implicated. Atypical antipsychotic drugs (in particular clozapine, olanzapine, risperidone and quetiapine) may cause marked weight gain over a relatively short period of time. Antidepressants such as TCAs, mirtazapine and SSRIs are also implicated. Mood stabilising drugs including lithium and sodium valproate also promote weight gain
- Ironically, better glycaemic control achieved by insulin, insulin secretagogues (e.g. glibenclamide, gliclazide) or thiazolidinedione (rosiglitazone, pioglitazone) therapy is often accompanied by weight gain, a problem because weight gain itself exerts a disadvantageous effects upon glucose control, increased blood pressure and sub-optimal lipid profiles. Weight gain may be lessened or prevented by to dietary measures and exercise, or combination therapy with metformin.
- In many cases the mechanism underlying drug-induced weight gain is complex and poorly understood. Sedation associated with some psychotropic medications may decrease physical activity and therefore reduce calorie consumption. Other drugs are known to increase appetite and may adversely affect the perception of satiety (the feeling of satisfaction or fullness normally experienced after eating).
- Medications that have been used to reduce drug induced weight gain include metformin (refer above) and the anticonvulsant drug topiramate.
Please consider these issues when preparing RMMR reports or education sessions. Contributions of content or suggested topics are welcome and should be sent directly to email@example.com.