From the FDA Drug Label
Ampicillin capsules and Ampicillin for oral suspension are indicated in the treatment of infections caused by susceptible strains of the designated organisms listed below: Infections of the genitourinary tract including gonorrhea - E. coli, P. mirabilis, enterococci, Shigella, S. typhosa and other Salmonella and nonpenicillinase-producing N. gonorrhoeae
Ampicillin is indicated as a treatment for gonorrhea, a sexually transmitted disease (STD), caused by nonpenicillinase-producing N. gonorrhoeae 1.
From the Research
Ampicillin is not typically indicated as a first-line treatment for sexually transmitted diseases (STDs), and its use is generally not recommended due to widespread resistance and the availability of more effective alternatives. For gonorrhea, which historically could be treated with ampicillin, resistance has become widespread, making it ineffective for this infection 2. Current guidelines recommend ceftriaxone (250-500mg IM as a single dose) plus azithromycin or doxycycline for gonorrhea 2. For syphilis, penicillin G (benzathine penicillin) remains the treatment of choice rather than ampicillin. Chlamydia is typically treated with azithromycin or doxycycline. While ampicillin is a penicillin-class antibiotic effective against some bacteria, its spectrum of activity and pharmacokinetic properties make it suboptimal for STD treatment. The development of antibiotic resistance among STD pathogens has further limited ampicillin's utility in this context 3, 4.
Some studies have investigated the use of ampicillin in combination with other antibiotics for the treatment of certain STDs, but these regimens are not commonly recommended due to the availability of more effective and convenient alternatives 5. For example, ampicillin may be used in combination with probenecid for the treatment of gonorrhea, but this regimen is not as effective as newer treatments and is associated with a higher risk of side effects 3.
In general, current STD treatment protocols prioritize medications with better efficacy, coverage, and resistance profiles, and ampicillin is not typically included in these protocols 2, 6. Therefore, ampicillin is not a recommended treatment for most STDs, and alternative antibiotics should be used instead.