Ethambutol should be used very cautiously in childhood tuberculosis due to which of its side effect ?
**Core Concept**
Ethambutol is an antitubercular medication primarily used in combination therapy for treating tuberculosis (TB). It works by inhibiting the synthesis of mycolic acid, an essential component of the mycobacterial cell wall. Ethambutol's effectiveness and potential side effects make it crucial to use it judiciously, especially in vulnerable populations like children.
**Why the Correct Answer is Right**
The correct answer is related to the potential optic neuropathy caused by ethambutol, particularly in children. Ethambutol can cause visual disturbances, including blurred vision, color vision defects, and even optic neuritis. This is due to its ability to inhibit the uptake of vitamin B12 by the retina, leading to damage to the optic nerve. Children are more susceptible to this side effect due to their developing visual system and potential for prolonged exposure to the medication.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while hepatotoxicity is a concern with many antitubercular medications, it is not the primary reason to use ethambutol cautiously in children.
**Option B:** This option is incorrect because while gastrointestinal side effects are common with many medications, they are not the primary concern with ethambutol in children.
**Option C:** This option is incorrect because while ototoxicity is a concern with some antitubercular medications, it is not the primary reason to use ethambutol cautiously in children.
**Clinical Pearl / High-Yield Fact**
When using ethambutol in children, it is essential to monitor their visual acuity and color vision regularly to detect any potential side effects early.
**Correct Answer:** C. Optic neuropathy.