What is the primary antibiotic indicated for treating pelvic inflammatory disease (PID)?

Doxycycline is the primary antibiotic indicated for treating pelvic inflammatory disease (PID) due to its effectiveness against the common pathogens associated with the condition, which typically include Chlamydia trachomatis and Neisseria gonorrhoeae. Doxycycline is a tetracycline antibiotic that works by inhibiting protein synthesis in susceptible bacteria, thus stopping their growth and aiding in the resolution of the infection.

PID is often treated with a combination of antibiotics to provide broad coverage; however, doxycycline is a key component in many regimens. Its oral bioavailability and good tissue penetration make it an ideal choice for treating infections in the pelvic area.

The other options listed do not serve as primary treatments for PID. Voriconazole is an antifungal medication used primarily for invasive fungal infections. Phenazopyridine is a urinary analgesic that alleviates symptoms of urinary tract irritation but does not treat infections. Famciclovir is an antiviral medication used to treat infections caused by certain types of viruses, such as herpes. None of these alternatives address bacterial infections related to PID.