What drug is commonly administered to neonates to prevent gonorrheal conjunctivitis?

Erythromycin is administered to neonates to prevent gonorrheal conjunctivitis because it is an effective antibiotic that targets Neisseria gonorrhoeae, the bacterium responsible for this infection. In many countries, prophylactic treatment with erythromycin (usually in the form of ointment) is applied to the eyes of newborns shortly after birth. This practice is crucial in preventing serious eye damage that can occur if gonorrheal infection is contracted at birth, as infants can acquire this infection during delivery from an infected mother.

The other medications listed do have clinical uses but are not typically indicated for this specific purpose. Penicillin, while effective against many bacteria, is not the drug of choice for gonorrheal conjunctivitis specifically in neonates. Tetracycline is also effective against a range of bacteria but is generally avoided in neonates due to potential side effects such as tooth discoloration. Amoxicillin is a broader-spectrum antibiotic and, while it can treat certain infections, it is not the standard prophylactic choice to prevent gonorrheal conjunctivitis in newborns. Thus, erythromycin remains the preferred and established option for this condition.