What is the most appropriate treatment for a patient with genital lesions suggestive of herpes genitalis?

In cases of genital lesions that are suggestive of herpes genitalis, the most appropriate treatment is an antiviral medication. Valacyclovir is an effective antiviral agent specifically indicated for the treatment of herpes simplex virus (HSV) infections, including genital herpes. This medication works by inhibiting viral replication, thereby reducing the severity and duration of symptoms during an active outbreak.

Early initiation of treatment with Valacyclovir can accelerate the healing of ulcers, diminish the duration of pain, and lower the frequency of recurrent episodes when taken as suppressive therapy. Its formulation allows for less frequent dosing, which can enhance patient compliance.

On the other hand, the other medications listed do not target HSV infections. Metronidazole is an antibiotic used primarily for bacterial infections and certain protozoal infections, not viral infections like herpes. Ceftriaxone is a broad-spectrum antibiotic commonly used to treat gonorrhea and other bacterial infections, while Benzathine penicillin G is specifically utilized for syphilis and some streptococcal infections. None of these effectively address a herpes simplex virus infection, making them unsuitable choices for this scenario. Therefore, Valacyclovir is the correct choice for treating suspected herpes genitalis lesions.