Sexually transmitted diseases (STDs) are infections primarily transmitted through sexual contact. Treatment depends entirely on the type of pathogen causing the disease. Antibiotics target and eliminate bacteria, making them effective only against bacterial STDs and certain protozoan infections. Viral infections, which account for many common STDs, cannot be treated with antibiotics. Determining the precise cause of the infection is the first step before any treatment can be prescribed.
Bacterial STDs and Targeted Antibiotic Therapies
Chlamydia, Gonorrhea, and Syphilis are the most common bacterial STDs, and each requires a specific antibiotic regimen. For Chlamydia, the preferred first-line treatment is typically a seven-day course of the oral antibiotic Doxycycline. This drug is generally more effective than alternatives, particularly for infections in the rectum or throat, and it works by disrupting the bacteria’s ability to produce proteins.
Treatment for Gonorrhea is complex due to the bacteria’s ability to rapidly develop resistance to multiple classes of antibiotics. Current guidelines recommend a high single dose of the injectable cephalosporin Ceftriaxone, often 500 mg, administered intramuscularly. Combination therapy with other antibiotics like Azithromycin is no longer recommended for uncomplicated cases because it is thought to contribute to resistance.
Syphilis, caused by the bacterium Treponema pallidum, is effectively treated with Penicillin, which remains the standard for all stages of the disease. A single intramuscular injection of long-acting Benzathine Penicillin G is typically curative for early-stage syphilis. Higher doses and multiple injections are required for later stages or if the central nervous system is involved. Treatment guidelines are constantly monitored and updated to adapt to changing resistance patterns, which is why a healthcare provider must be consulted for the most current regimen.
Why Antibiotics Fail Against Viral and Other STDs
Antibiotics are ineffective against many sexually transmitted infections because they are not caused by bacteria. Viral STDs, such as Human Immunodeficiency Virus (HIV), Herpes Simplex Virus (HSV), Human Papillomavirus (HPV), and Hepatitis B and C, do not have the cellular mechanisms that antibiotics target. Viruses are genetic material enclosed in a protein shell that hijack host cells to replicate, a process that antibiotics cannot interrupt.
Treatments for viral STDs focus on managing the infection through specific antiviral medications, which interfere with the viral replication cycle. For example, daily suppressive therapy with antivirals can reduce the frequency and severity of genital herpes outbreaks. The body often clears HPV naturally, but a vaccine is available to prevent infection with the types most likely to cause cancer.
Other STDs are caused by parasites or protozoa, which require non-antibiotic drugs for treatment. Trichomoniasis, caused by the protozoan Trichomonas vaginalis, is typically treated with an antiparasitic medication, such as Metronidazole or Tinidazole. Understanding the pathogen type is essential, as using an antibiotic for a viral or parasitic infection will fail to cure the disease and contribute to antibiotic resistance.
Ensuring Treatment Success and Addressing Resistance
Successfully treating a bacterial STD requires strict adherence to the prescribed medication. It is imperative to complete the entire course of antibiotics exactly as prescribed, even if symptoms disappear quickly. Stopping treatment prematurely can leave resilient bacteria alive, allowing them to multiply and potentially develop resistance.
Partner notification and simultaneous treatment, often through Expedited Partner Therapy, are necessary to prevent reinfection and interrupt the chain of transmission. Treating all partners who may have been exposed ensures that a cured individual is not immediately reinfected by an untreated partner. This strategy is an important public health measure to limit the spread of infection.
The greatest concern in STD treatment is the growing threat of drug resistance, particularly in Gonorrhea, which has developed resistance to nearly every class of antibiotic. Resistance to the last remaining recommended drug, Ceftriaxone, has been reported in several parts of the world, making careful surveillance and appropriate prescribing necessary. Follow-up testing, often called a “Test of Cure,” is recommended for certain infections, especially Gonorrhea, to confirm successful treatment and detect potential reinfection.