Which drug may cause decline in vision due to optic neuritis in a patient being treated for tuberculosis?

The correct answer is associated with ethambutol, which is well-documented for its potential side effect of causing optic neuritis. Ethambutol works as an antitubercular agent by inhibiting the synthesis of the bacterial cell wall, but one of its notable adverse effects is its impact on visual acuity due to its toxicity to the optic nerve.

Patients taking ethambutol may experience symptoms like changes in vision, such as decreased visual acuity or red-green color blindness, which can be indicators of optic neuritis. The mechanism behind this is thought to involve the drug interfering with retinal nerve functioning.

In clinical practice, monitoring for symptoms of vision changes is crucial when patients are prescribed ethambutol, especially at higher doses or with prolonged use. This emphasis on regular eye examinations and patient education about reporting any visual disturbances is essential in managing the risks of this medication effectively.