Sexually-transmitted infection

Organism	Disease	First-line treatment	Treatment if allergic	Treatment if pregnant
Chlamydia trachomatis	chlamydia	azithromycin 1 g po once		azithromycin 1 g po once, or amoxicillin 500 mg po tid for 7 days
Chlamydia trachomatis serovars L1, L2, L3	Lymphogranuloma venereum	doxycycline 100 mg PO for 3 weeks		erythromycin 500 mg PO qid for 3 weeks
Haemophilus ducreyi	chancroid	azithromycin 1 g po once	ceftriaxone 250 mg IM once	usual treatment
Klebsiella granulomatis	granuloma inguinale (donovanosis)	doxycycline 100 mg po bid for 3 weeks		erythromycin
Neisseria gonorrhoeae	gonorrhea	ceftriaxone 250 mg IM once + azithromycin 1 g PO once	gentamicin 240 mg IM once + azithromycin 2 g PO once	usual treatment
Treponema pallidum pallidum	primary, secondary, and EL syphilis	penicillin 2.4 MU IM once	doxycycline 100 mg PO bid for 14 days	usual treatment
	LL and tertiary syphilis	penicillin 2.4 MU IM weekly for 3 weeks	desensitization or doxycycline 100 mg PO bid for 28 days	usual treatment
	neurosyphilis	penicillin 4 MU IV q4h for 10-14 days	desensitization	usual treatment
Trichomonas vaginalis	trichomoniasis	metronidazole 2 g PO once		usual treatment