Doxycycline is a tetracycline antibiotic used to treat several sexually transmitted diseases (STDs), including chlamydia, gonorrhea, and syphilis. It works by inhibiting bacterial protein synthesis.
It is a broad-spectrum antibiotic, meaning it works against various microbes. It also has a long elimination half-life, requiring fewer daily doses.
Doxycycline is almost completely absorbed through the gut (95% of the oral dose). It's also relatively safe in patients with chronic kidney disease, as only a fraction of the drug is eliminated through the kidneys.
Typical treatment regimens for STDs:
- Gonorrhea: 7-day oral course of doxycycline with a single intramuscular injection of ceftriaxone.
- Syphilis: 100mg oral dose bi-daily for at least 2 weeks.
- Chlamydia: 100mg bi-daily or 200mg once-daily dosage for 7 days.
- PID: doxycycline 100mg twice daily with metronidazole 500mg twice daily for 7 days.
Side effects of doxycycline may include gastrointestinal problems (nausea, vomiting, esophageal erosion, diarrhea, anorexia, and enterocolitis), skin reactions (dermatitis, rash, photosensitivity, erythroderma), and in some cases, an immune reaction like anaphylaxis.
Clinical trials have explored doxycycline's role as a preventative medicine for STDs, with promising results. This includes doxycycline post-exposure prophylaxis for STD prevention in high-risk groups.
While doxycycline is an effective drug, there are increasing concerns about bacterial resistance. It's important to always use antibiotics as directed by a healthcare professional.
Starts working 1-2 hours after ingestion. A full course lasts about a week or two, effectively curing most bacterial STDs susceptible to this antibiotic within this timeframe.