Gonorrhea is a common sexually transmitted infection (STI) caused by the bacterium Neisseria gonorrhoeae. It can infect the genitals, rectum, and throat. Untreated gonorrhea can cause serious health complications like pelvic inflammatory disease, infertility and increased risk of HIV transmission. Antibiotic treatment is recommended for gonorrhea to stop infection and prevent complications. Ciprofloxacin is a commonly used antibiotic, but its efficacy in treating gonorrhea has decreased over the years due to increasing resistance. This article reviews the current evidence on whether ciprofloxacin 500mg can effectively cure gonorrhea.
Overview of gonorrhea
Gonorrhea, also called “the clap”, is spread through unprotected oral, vaginal, or anal sex with an infected partner. The infection often has no symptoms, especially in women, but some common signs include:
– Thick, cloudy or bloody discharge from penis or vagina
– Pain or burning sensation when urinating
– Swelling and pain in testicles (men)
– Increased vaginal bleeding between periods (women)
– Rectal pain, discharge, bleeding (anal infection)
– Sore throat (oral infection)
If untreated, gonorrhea can cause:
– Pelvic inflammatory disease in women, leading to chronic pelvic pain, infertility and ectopic pregnancy
– Scarring of reproductive tract in men (epididymitis) causing infertility
– Increased risk of HIV transmission
– Disseminated gonococcal infection (joints, skin, heart valves affected)
Gonorrhea diagnosis is made through a urine test or swab sample from infected site. Due to increasing antibiotic resistance, the CDC recommends dual therapy with injectable ceftriaxone and oral azithromycin as first line treatment.
Mechanism of antibiotic resistance in gonorrhea
Antibiotic resistance occurs when bacteria undergo genetic changes that reduce or eliminate the effectiveness of medicines. Resistance has emerged in N. gonorrhoeae due to the following reasons:
– Overuse of antibiotics like penicillins, tetracyclines, fluoroquinolones over the decades
– Ability of gonococcus to acquire new genetic material through plasmid exchange
– Spontaneous gene mutations leading to altered bacterial proteins that block antibiotic action
– Natural selection of resistant strains due to antibiotic pressure
As a result, gonorrhea has become resistant to multiple previously effective oral antibiotics like penicillin, tetracyclines and fluoroquinolones like ciprofloxacin.
Ciprofloxacin mechanism of action
Ciprofloxacin is a second generation fluoroquinolone antibiotic. It stops bacterial growth by inhibiting two essential bacterial enzymes:
– DNA gyrase – needed for DNA replication
– Topoisomerase IV – required for separating replicated DNA
By blocking these enzymes, ciprofloxacin prevents bacterial cell division and reproduction. This produces a bactericidal effect.
Ciprofloxacin is available as 250mg, 500mg and 750mg tablets. The adult dose is 500-750 mg every 12 hours for most infections.
Ciprofloxacin resistance in N. gonorrhoeae
Fluoroquinolones like ciprofloxacin were effective first-line drugs for gonorrhea in the 1980s-1990s. However, resistance emerged rapidly due to:
– Single point mutations in the DNA gyrase and topoisomerase IV enzymes prevented ciprofloxacin binding
– Efflux pumps in gonococci actively pumped out ciprofloxacin from bacterial cells
By 2007, fluoroquinolone resistance was identified globally including in the United States. By 2019, resistance rates to ciprofloxacin were >95% among gonococcal isolates in many countries as per the European CDC. Due to this high-level resistance, the CDC no longer recommends fluoroquinolones for gonorrhea treatment.
Current evidence on ciprofloxacin efficacy in gonorrhea
Multiple clinical studies and microbiological data show that ciprofloxacin 500mg oral dose is no longer effective for treating gonorrhea infections:
– A 2018 Canadian study found 98% of gonococcal isolates resistant to ciprofloxacin.
– A report from England and Wales showed 99.7% of gonorrhea samples were ciprofloxacin resistant.
– In the United States, resistance rates increased from 99% cure rates.
| Study | Findings |
|---|---|
| Wang 2018, China | 92% clinical failure rate with ciprofloxacin vs 2% failure with ceftriaxone/azithromycin |
| Tanaka 2002, Japan | 51% failure rate with ciprofloxacin 500mg single dose |
Based on this evidence, public health agencies including the WHO strongly advise against using ciprofloxacin and other fluoroquinolones to treat gonococcal infections.
Reasons for ciprofloxacin treatment failure
The high rates of clinical and microbiological failure seen with ciprofloxacin 500mg in gonorrhea are due to:
– Presence of gyrase/topoisomerase mutations in >95% of N. gonorrhoeae strains leading to target site resistance
– Overexpression of multidrug efflux pumps reducing intracellular ciprofloxacin accumulation
– Co-existing sexually transmitted pathogens like Chlamydia trachomatis which are unaffected by ciprofloxacin monotherapy
– Inadequate drug levels in pharyngeal infections treated with a single 500mg oral dose
– Re-infection from an untreated sexual partner harboring a new ciprofloxacin-resistant strain
Alternate antibiotic options for gonorrhea
Based on the widespread resistance, ciprofloxacin monotherapy cannot be relied upon to cure gonorrhea infections. The CDC and WHO recommend combination therapy with injectable ceftriaxone and oral azithromycin as the only first-line empiric regimen. Back-up options for ceftriaxone-resistant gonorrhea include:
– Gentamicin + Azithromycin
– Gemifloxacin + Azithromycin
– Delafloxacin
However, resistance surveillance data shows susceptibility is declining for these alternate antibiotics too. Due to multi-drug resistant gonorrhea, new antibiotic options are urgently needed. Till then, prevention through safer sexual practices remains essential.
Conclusion
In summary, ciprofloxacin 500mg single oral dose should not be used for treating gonorrhea infections. High rates of clinical failure and fluoroquinolone resistance among global N. gonorrhoeae isolates means ciprofloxacin monotherapy cannot provide effective cure. Combination therapy with ceftriaxone and azithromycin remains the only recommended first-line treatment for gonorrhea. However, continued emergence of drug resistance threatens management of this common sexually transmitted disease.