Although medicinal treatments for gonorrhea (GC) have been widely available for decades, the disease remains quite relevant. Like many pathogens, GC has evolved over the years and has cycled through several stages of therapeutic treatment to the current multi-drug approach. Having witnessed this evolution from what was originally a fairly simple, oral-based drug treatment to a now somewhat complex, multi-drug regimen requiring an injectable-only product has created obstacles to effective and long-lasting treatment.
Evolution of GC and its Treatment
Through the 1990s, clinicians had the luxury of using single drugs to treat GC (see FIGURE 1). However, as fluoroquinolones (ie, ciprofloxacin, ofloxacin, levofloxacin) began to fail as a single-drug treatment in the late 90s and early 2000s (themselves having replaced penicillin and tetracycline in the 1980s due to lagging efficacy), it became necessary to treat GC using two separate drugs simultaneously.
Crucial to this change is the introduction of injectable medications as part of an effective course of treatment. Injectable cephalosporins quickly became integral to GC treatment throughout the 2000s. The final single-drug treatment methodology collapsed around 2012, leaving a single current recommended antibiotic treatment: a combination of oral azithromycin and injectable ceftriaxone.
Impact of Drug Therapy Changes
Inherently, moving from a single, oral therapy to a dual therapy of oral and injectable drugs is challenging from a pharmaceutical management and administration standpoint, but given gonorrhea’s nature as a social, sexually transmitted infection (STI), the effects of this change on the logistics of actual patient interaction and treatment have been significant.
A central, long-standing construct of effective GC treatment was the practice of partner directed therapy. Patients who tested positive for GC and were subsequently treated were then given medications to take and provide to sexual partners to mitigate further spread. With the introduction of injectable medications into the regimen, partner directed therapy is no longer a sustainable option, and this lost approach to STI treatment is likely to have a negative public health impact.
Challenges Remain in the Clinical Lab
In defending against the development and spread of GC, many clinical labs in hospital settings lack highly effective diagnostic tools. The concept of culture is promising (eg, co-linear with drug resistance testing), but in practice, such tests can be slow and lack sensitivity.
That said, nucleic acid amplification tests (NAATs) are effective in that they can provide rapid diagnosis and assessments of diagnosed cases (ie, NAAT diagnosed). That said, no currently available NAAT test assesses the organism’s drug susceptibility.
It is worth noting that currently, laboratories do not have access to FDA-approved NAATs for the throat and rectum; areas known to harbor GC infection. We are missing those cases, by and large, and it is becoming increasingly vital to be able to do test-of-cure at such sites. As such, testing with NAAT and the utilization of dual-drug therapies remain the frontline defenses of GC.
As GC infections continue to evolve in both origin and susceptibility, the logical ideal would be to retain some semblance of simplicity when combatting this communicable disease. With some now in trial stages, the immediate future facing clinical and diagnostic laboratories includes NAATs that can provide intelligence on possible courses of treatment precluding the need for multiple drugs. This will allow for assessments of drug susceptibility to be made concomitant with diagnosis. The ability to use individual, traditionally established drugs for cases determined to be vulnerable via NAAT would release the immense evolutionary pressure exerted on an organism when all cases are treated with the same drug(s) in all places.
Further afield, NAATs developed to detect drug resistance could allow for drug resistance assessments or estimates based upon an individual patient’s genetic make up. This concept of individualized medicine enables medication differentiation that would signal an exit from the era of empirical treatment, the monolithic treatment of all cases with the same drugs, and the reintroduction of partner directed therapy.
Mark W. Pandori, PhD, is the director of the Alameda County Public Health Laboratory in Oakland, California, and is an associate clinical professor in the Department of Laboratory Medicine at the University of California San Francisco School of Medicine.
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