Why does my mouth taste so bitter after using chloramphenicol eye drops?

Generally, a bitter taste in the mouth after using chloramphenicol eye drops is due to physiological factors—specifically, the connection between the tear ducts and the oral cavity. However, pathological conditions such as stomatitis, cholecystitis, gastritis, and neuritis may also cause a bitter taste. If abnormal symptoms occur, prompt medical attention is recommended. Detailed explanations are as follows:

1. Communication between tear ducts and the oral cavity

After instilling chloramphenicol eye drops into the eyes, some of the medication may pass through the lacrimal passage—including the upper and lower puncta, lacrimal canaliculi, common lacrimal duct, and nasolacrimal duct—into the nasal cavity, which is connected to the oral cavity. Chloramphenicol eye drops have a naturally bitter taste, and when the medication reaches the mouth, it can cause a bitter sensation. This is a common physiological phenomenon following eye drop use and generally does not require concern.

2. Stomatitis

Damage to the oral mucosa can lead to mucosal erosion. In such cases, sensitivity to drug components may increase, intensifying the bitter taste. Stomatitis is usually accompanied by symptoms such as oral pain, redness, swelling, or ulcers. It is recommended to clean and apply affected areas under medical guidance using products such as compound borax mouthwash, watermelon frost spray, or compound algin dressing.

3. Cholecystitis

Obstruction of the cystic duct may lead to bile accumulation and result in cholecystitis. Patients with cholecystitis may experience bile reflux, and when bile flows back into the oral cavity, it can also cause a bitter taste. If a patient has both cholecystitis and uses eye drops, the underlying cause of the bitterness may be confused. Cholecystitis is typically associated with symptoms such as nausea and upper abdominal pain. Treatment should follow medical advice and may include medications such as atropine sulfate tablets, racemic hyoscine tablets, or phloroglucinol.

4. Gastritis

Gastritis is commonly caused by infection, dietary factors, and other triggers, and often presents with indigestion, acid reflux, and similar symptoms. These disturbances may affect taste perception, making even mild drug flavors more pronounced. Medications such as omeprazole enteric-coated capsules, domperidone capsules, or mosapride citrate tablets may be used under medical supervision to suppress gastric acid secretion.

5. Neuritis

Neuritis may be triggered by trauma, metabolic disorders, or other causes, leading to sensory disturbances and taste abnormalities that amplify the perception of drug flavor, resulting in a bitter taste. Neurological conditions may also present with headaches, dizziness, or limb numbness. Symptom relief may involve medications such as mecobalamin tablets, phenytoin sodium tablets, or gabapentin capsules, as advised by a physician.

It is recommended to maintain a healthy lifestyle, ensure adequate sleep, improve dietary habits, and regulate overall physical condition to support general health.