MRCP UK EXAMINATIONS

Detailed explanation-1: -The most important complication of ethambutol therapy is retrobulbar neuritis manifested by impaired visual acuity, color blindness and restricted visual fields. Except in patients with pre-existing ophthalmic disease, optic neuritis is extremely rare when ethambutol is used at standard doses (15 mg/kg).

Detailed explanation-2: -Ethambutol is used primarily as the fourth drug when there is a possibility of resistance to other first-line drugs. The most serious adverse effect is retrobulbar neuritis, which appears to be dose related and manifests with blurred vision, central scotoma, and red-green color blindness.

Detailed explanation-3: -Headache, loss of appetite, upset stomach, or nausea/vomiting may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects.

Detailed explanation-4: -Ethambutol-induced optic neuropathy (EON) is a well-known complication arising from the use of ethambutol, the severity of which is in a dose-dependent manner. The toxicity is usually reversible on discontinuation of the therapy. However, there have been several reports of permanent damage to the visual function.

Detailed explanation-5: -Ethambutol is the most commonly implicated drug. It is generally well tolerated, but known to cause optic neuritis, more specifically retro bulbar neuritis causing blurred vision, decreased visual acuity, central scotomas, and loss of red-green color vision.