Which medication, Clarithromycin, Amoxicillin, or Tegoprazan, causes dysgeusia (bitter taste in the mouth)?

From the Guidelines

Clarithromycin is the medication most commonly associated with causing a bitter taste in the mouth, as evidenced by studies showing that higher doses of clarithromycin are associated with bitter taste, nausea, and elevated hepatic enzymes 1. This side effect occurs because clarithromycin is partially metabolized in the saliva and can be secreted into the oral cavity, directly stimulating taste receptors. Some key points to consider include:

• Amoxicillin rarely causes taste disturbances, and when it does, it's typically described as a metallic rather than bitter taste 1.
• Tegoprazan, a potassium-competitive acid blocker, has not been widely reported to cause significant taste disturbances.
• If you experience persistent bitter taste while taking clarithromycin, staying well-hydrated, using sugar-free gum or mints, and completing the full prescribed course despite this side effect is recommended, as the taste disturbance is temporary and will resolve after completing treatment. The most recent and highest quality studies suggest that clarithromycin has a higher likelihood of causing dysgeusia compared to amoxicillin and tegoprazan 1. Some important considerations when prescribing clarithromycin include:
• Monitoring for adverse effects such as bitter taste, nausea, and elevated hepatic enzymes, especially at higher doses.
• Considering alternative treatments, such as azithromycin, which may have a better tolerability profile 1.
• Ensuring patient adherence to the prescribed treatment course, despite potential side effects, to maximize treatment efficacy.

From the FDA Drug Label

The most frequent adverse reactions for both adult and pediatric populations observed in clinical trials are abdominal pain, diarrhea, nausea, vomiting and dysgeusia. The most frequently reported adverse events for patients who received triple therapy (amoxicillin/clarithromycin/ lansoprazole) were diarrhea (7%), headache (6%), and taste perversion (5%)

• Clarithromycin causes dysgeusia (bitter taste in the mouth) as reported in its clinical trials.
• Amoxicillin causes taste perversion, which may be related to dysgeusia, as reported in its clinical trials for triple therapy. There is no information about Tegoprazan in the provided drug labels. 2 3

From the Research

Medication-Induced Dysgeusia

• Dysgeusia, or a bitter taste in the mouth, can be a side effect of various medications.
• The provided studies do not directly address which medication, Clarithromycin, Amoxicillin, or Tegoprazan, causes dysgeusia.

Adverse Effects of Medications

• Clarithromycin has been reported to cause digestive system upsets, including adverse events such as nausea, diarrhea, and abdominal pain 4, 5.
• Amoxicillin is a beta-lactam agent that can cause similar side effects to clarithromycin, but the provided studies do not specifically mention dysgeusia as a side effect.
• Tegoprazan has been reported to be well tolerated in healthy subjects, with no significant safety concerns raised 6, 7.

Lack of Direct Evidence

• There are no research papers provided that directly address the question of which medication causes dysgeusia.
• The studies primarily focus on the pharmacokinetics, efficacy, and safety of the medications, rather than specific side effects like dysgeusia 6, 8, 4, 5, 7.