Drug-Related Halitosis: A Narrative Review

INTRODUCTION: This article provides a current narrative review of the medications that may cause halitosis as a side effect. Halitosis is frequently associated with important social, psychological, and emotional aspects of life; therefore, it is crucial for health care providers to be able to diagnose and manage it effectively. METHODS: A literature review was conducted using the PubMed and EMBASE/OVID databases between January 2015 and December 2024 to find the latest relevant articles, focusing on systematic reviews and literature published between 2020 and 2025. RESULTS: Medications can lead to halitosis (bad breath) either intra- or extra-orally. Research has identified several medications that may cause extra-oral halitosis as a side effect. These include ranitidine, cysteamine, certain antifungals, peppermint oil, aspirin and other NSAIDs, PX-12, silybin, disulfiram, suplatast tosilate, dimethyl sulfoxide, levocarnitine, nitrates and nitrites, paraldehyde, chloral hydrate, and iodine-containing medications. Intra-oral halitosis is mostly related to medications that cause xerostomia and MRONJ as side effects. DISCUSSION: Multiple groups of medications can cause intra- or extra-oral halitosis. prior knowledge about these medications and their underlying mechanisms that will lead to halitosis will enable clinicians to diagnose and manage this condition more effectively. It is also wise for clinicians to consider recreational drugs like crack, cocaine, and smokeless tobacco when looking for the underlying reason for halitosis. SUMMARY: Multiple groups of medications can act as an underlying cause for halitosis. However, more research is needed to monitor halitosis as an independent side effect and to investigate the mechanism by which each medication causes halitosis.