What antibiotic is recommended for a patient with proctitis?

Antibiotic for Proctitis

For acute proctitis in patients with recent receptive anal intercourse, treat empirically with ceftriaxone 125 mg IM (or 1 g IM/IV) plus doxycycline 100 mg orally twice daily for 7 days to cover both gonorrhea and chlamydia. 1

Clinical Context and Pathogen Coverage

Acute proctitis of recent onset in sexually active individuals is most commonly caused by sexually transmitted infections, particularly Neisseria gonorrhoeae and Chlamydia trachomatis. 1, 2 The empiric dual-therapy approach is critical because:

• Gonorrhea requires immediate coverage with a cephalosporin due to widespread fluoroquinolone resistance 1
• Chlamydia requires extended therapy with doxycycline to ensure eradication 1
• Coinfection is common, making dual therapy essential even before diagnostic confirmation 2

Diagnostic Evaluation Before Treatment

Patients should undergo:

• Anoscopy to visualize anorectal inflammation and detect purulent discharge 1
• Gram stain of anorectal secretions looking for polymorphonuclear leukocytes 1
• Nucleic acid amplification testing (NAAT) on rectal swabs for gonorrhea and chlamydia 1, 2
• Testing for HSV, syphilis (T. pallidum), and consider lymphogranuloma venereum (LGV) serovars in appropriate clinical contexts 1, 2

Specific Treatment Regimens

Standard Empiric Therapy

• Ceftriaxone 125 mg IM (or 1 g IM/IV for more severe cases) 1
• PLUS Doxycycline 100 mg orally twice daily for 7 days 1

The 2024 European Association of Urology guidelines support similar regimens with ceftriaxone 1 g plus azithromycin 1 g for gonococcal infections, though the CDC regimen with doxycycline provides more reliable chlamydial coverage. 1

Alternative Regimens for Cephalosporin Allergy

• Gentamicin 240 mg IM single dose plus azithromycin 2 g orally single dose 1
• Gemifloxacin 320 mg orally single dose plus azithromycin 2 g orally single dose 1

Pathogen-Specific Adjustments

If LGV is suspected (severe proctitis with systemic symptoms):

• Doxycycline 100 mg orally twice daily for 21 days (extended course) 3

If herpes proctitis is identified (painful ulcerations):

• Refer to HSV-specific antiviral therapy guidelines 1

Critical Clinical Pitfalls

Do not delay empiric treatment if anorectal pus or polymorphonuclear leukocytes are present on examination—start antibiotics immediately pending culture results. 1 This is particularly important because:

• Untreated STI proctitis can progress to systemic complications 4
• HIV-coinfected patients may have more severe disease requiring prompt intervention 1, 4
• Delayed treatment increases transmission risk to sexual partners 1

Obtain sexual history thoroughly, including receptive anal intercourse practices, as this directly impacts differential diagnosis and may reveal undiagnosed HIV or other STIs. 4, 2 One case report demonstrated chlamydial proctitis mimicking inflammatory bowel disease in an HIV-positive patient, emphasizing the importance of STI screening. 4

Partner Management and Follow-Up

• Sexual partners within the last 60 days must be evaluated and treated empirically for gonorrhea and chlamydia, maintaining patient confidentiality 1
• Follow-up based on specific etiology and symptom severity—reinfection can be difficult to distinguish from treatment failure 1
• Perform culture with antimicrobial susceptibility testing for gonorrhea-positive cases to guide treatment if initial therapy fails 1

Important Distinctions

This question addresses proctitis (rectal inflammation), which differs from prostatitis (prostate inflammation). Prostatitis requires different antibiotics—typically fluoroquinolones or broad-spectrum agents for 2-4 weeks for acute bacterial prostatitis. 5, 6 Do not confuse these conditions despite similar nomenclature.