Treatment Methods Infection (Pathogen) Primary Alternative Comment(s) Chlamydia (Chlamydia trachomatis) Doxycycline, 100 mg twice daily for 7 days OR azithromycin dihydrate, single dose 1 g Erythromycin (base), 500 mg four times daily for 7 days OR ofloxacin, 300 mg twice daily for 7 days OR levofloxacin, 500 mg daily for 7 days Screen and treat patients for gonorrhea. If patient is pregnant or lactating, use azithromycin. Gonorrhea (Neisseria gonorrhoeae) Ceftriaxone sodium, 125 mg intramuscularly OR cefixime, single dose 400 mg OR ciprofloxacin, single dose 500 mg OR ofloxacin, single dose 400 mg OR levofloxacin, single dose 250 mg OR gatifloxacin, single dose 400 mg OR azithromycin, single dose 1 g OR doxycycline, 100 mg twice daily for 7 days Spectinomycin, 2 g intramuscularly OR cefotaxime sodium, single dose 500 mg intramuscularly OR ceftizoxime sodium, 500 mg intramuscularly OR cefoxitin sodium, 2 g intramuscularly with probenecid, 1 g OR lemofloxacin, single dose 400 mg OR norfloxacin, single dose 800 mg Screen and treat patients for chlamydia. Note that fluoroquinolones are contraindicated for patients who are younger than 18 years and patients who are pregnant or lactating. Herpes simplex virus Primary HSV (episodic treatment) Acyclovir, 200 mg five times daily for 10 days (or 400 mg three times daily for 7 to 10 days) OR valacyclovir hydrochloride, 1 g twice daily for 7 to 10 days OR famciclovir, 125 mg three times daily for 7 to 10 days ... Physicians treat herpes simplex virus with a tiered approach, first attempting to control episodes or "flare-ups" with episodic treatment. Patients who have more than six episodes per year, however, require more aggressive treatment and are given daily suppressive treatment. Recurrent HSV (episodic treatment for < 6 episodes per year) Acyclovir, 400 mg three times daily for 5 days and 800 mg three times daily for 3 days OR famciclovir, 125 mg twice daily for 5 days OR valacyclovir, 500 mg twice daily for 3 days ... In either situation, patients' infection status should be reassessed after 1 year of continuous treatment. Twenty percent of patients have a reduction in recurrence frequency after 1 year of treatment for this sexually transmitted infection. Recurrent HSV (suppressive treatment for 6 episodes per year) Acyclovir, 400 mg twice daily OR valacyclovir, 1 g daily OR famciclovir, 250 mg twice daily ... Patients with recurrent HSV proctitis may be treated with acyclovir, 400 mg five times daily for 10 days. Nonspecific urethritis or cervicitis Doxycycline, 100 mg twice daily for 7 days OR azithromycin, single dose 1 g Erythromycin (base), 500 mg four times daily for 7 days OR ofloxacin, 300 mg twice daily for 7 days OR levofloxacin, 500 mg daily for 7 days Screen patients for chlamydia. If patient is pregnant or lactating, use azithromycin. Syphilis (Treponema pallidum)|| Penicillin G benzathine, single dose, 2.4 million units intramuscularly For patients who are hypersensitive to penicillin: Doxycycline, 100 mg twice daily for 14 days OR tetracycline, 500 mg four times daily for 14 days OR ceftriaxone, 1 g daily intramuscularly or intraveneously for 8 to 10 days For patients with latent syphilis (>1 year), syphilis of unknown duration, syphilis with cardiovascular involvement, or tertiary syphilis, use weekly treatment of 2.4 million units of penicillin G benzathine delivered intramuscularly for 3 weeks.¶ If serologic test results do not show improvement 3 months after treatment, consider a lumbar puncture to rule out involvement of cerebrospinal fluid. Trichomoniasis (Trichomonas vaginalis) Metronidazole, single dose 2 g OR metronidazole, 500 mg twice daily for 7 days ... Metronidazole is contraindicated in the first trimester of pregnancy. If a diagnosis is made during this period, delay treatment until after the first trimester, when patients can be treated with metronidazole.

^* Unless otherwise specified, delivery method for all medications listed is tablets, capsules, or caplets by mouth.

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2).

Keep up to date with changing regimens via your local public health authorities or infectious disease consultant.

Nonspecific cervicitis or urethritis describes sexually transmitted infections caused by Mycoplasma genitalium, Mycoplasma hominis, or Ureaplasma.

^|| Syphilis is classified as being early or late; primary, secondary, or tertiary; and latent.

^¶ For patients with a hypersensitivity to pencillin, physicians should prescribe doxycycline, 100 mg twice daily for 28 days OR tetracycline, 500 mg four times daily for 28 days.