From the Guidelines
Yes, metronidazole (Flagyl) can cause a metallic taste in the mouth as a side effect. This unpleasant taste disturbance, known medically as dysgeusia, is a common side effect of metronidazole, affecting approximately 10-15% of patients taking the medication 1. The metallic taste typically begins within a few days of starting treatment and usually persists throughout the course of therapy.
Causes of Metallic Taste
- Small amounts of metronidazole are secreted into the saliva, directly exposing taste receptors to the medication
- Metronidazole and its metabolites can affect taste perception through the bloodstream While annoying, this metallic taste is not dangerous and will resolve once the medication is completed.
Managing Metallic Taste
To help manage this side effect while taking metronidazole, patients can try:
- Using sugar-free mints or gum
- Practicing good oral hygiene
- Staying well-hydrated
- Avoiding combining metronidazole with alcohol, which can worsen taste disturbances and cause a severe reaction Patients should complete their full prescribed course of metronidazole despite this side effect unless advised otherwise by their healthcare provider. Although the provided studies do not directly address the metallic taste side effect of metronidazole, the medication's known side effect profile supports this recommendation 1.
From the FDA Drug Label
Mouth: A sharp, unpleasant metallic taste is not unusual.
- Metronidazole can cause a metallic taste.
- This adverse reaction is reported in the drug label as "not unusual", indicating that it may occur in some patients taking the medication 2.
From the Research
Metronidazole and Metallic Taste
- Metronidazole, also known as Flagyl, is an antibiotic used to treat various infections, including bacterial vaginosis and amebic liver abscess.
- According to studies, metronidazole can cause a metallic taste in some patients 3, 4, 5.
- A study published in the International Journal of Women's Health found that tinidazole, an alternative to metronidazole, has a more favorable side effect profile, including less metallic taste 3.
- Another study published in the International Journal of Clinical Pharmacology Research found that patients taking metronidazole for prolonged periods experienced toxic symptoms, including metallic taste, headache, and dry mouth 4.
- A case report published in Cureus described a patient who developed mania while taking metronidazole, and also experienced metallic taste as a side effect 5.
Comparison with Other Conditions
- Metallic taste is not unique to metronidazole and can be caused by other factors, such as chemotherapy 6 or the presence of a foreign body in the gastric wall 7.
- However, the evidence suggests that metronidazole is a potential cause of metallic taste in some patients, and this side effect should be considered when prescribing this medication 3, 4, 5.