Some body odours come from substances that emanate from the body and are present in secretions, exhaled air or expelled gas. Other odours come from substances formed by the microflora on the skin or mucous membranes. Each person has a unique body odour that varies with age, the menstrual cycle, heat, hygiene practices, emotions (such as stress or pain), physical exercise, diet, and the consumption of particular foods (such as garlic or spices) or substances such as alcohol or tobacco.

Many drugs alter body odour, through various mechanisms. Some increase sweat production, including adrenaline, amphetamines, pseudoephedrine, tramadol, the antidepressants fluoxetine, paroxetine and venlafaxine, pregabalin, gabapentin, codeine, omeprazole, and drugs that trigger hot flushes.

Some drugs alter mouth odour by interfering with gastrointestinal transit and causing eructation (belching): nicotine, peppermint essential oil and HIV protease inhibitors. Others decrease saliva production or alter the local microflora: some antidepressants and neuroleptics, opioids, and antiseptic mouthwashes.

Some drugs are odorous themselves or produce odorous compounds: lithium, bisphosphonates. Yet others alter the composition of the microflora (antibiotics, antiseptics and antifungals) or disrupt the endocrine system.

Abnormal body odour can have social, psychological and other consequences. If these become too troublesome for the patient or the people around them, and a drug appears responsible, there are various options to consider: the drug could be replaced, stopped, or continued with intensified hygiene measures, or the patient could accept the odour and possibly modify it with cosmetics.

©Prescrire 1 July 2022

Source: "Drug-induced abnormal body odour" Prescrire International 2022; 31 (239): 187-189. Subscribers only.

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