From the Guidelines
Doxycycline should be prescribed at a dose of 100 mg taken orally twice daily for 7 days to treat many sexually transmitted infections (STIs) including chlamydia, non-gonococcal urethritis, and as part of combination therapy for gonorrhea. This recommendation is based on the Centers for Disease Control and Prevention (CDC) guidelines, which suggest that doxycycline is an effective treatment for these infections 1. The medication should be taken with a full glass of water, and patients should remain upright for at least 30 minutes after taking it to prevent esophageal irritation. It can be taken with or without food, though taking it with food may reduce stomach upset. Patients should avoid dairy products, antacids, iron supplements, and calcium supplements within 2 hours of taking doxycycline as these can reduce absorption. Some key points to consider when prescribing doxycycline for STIs include:
- The importance of completing the full course of antibiotics, even if symptoms improve before finishing treatment 1
- The need for patients to abstain from sexual activity until treatment is complete and partners should be treated simultaneously to prevent reinfection 1
- The potential for doxycycline to be used as part of combination therapy for gonorrhea, and the importance of following CDC guidelines for treatment 1 It's also important to note that doxycycline works by inhibiting bacterial protein synthesis, preventing bacteria from growing and multiplying. Overall, doxycycline is a effective treatment for many STIs, and when used correctly, can help to reduce the risk of complications and transmission to others.
From the FDA Drug Label
Adults: The usual dose of oral doxycycline is 200 mg on the first day of treatment (administered 100 mg every 12 hours) followed by a maintenance dose of 100 mg/day Uncomplicated gonococcal infections in adults (except anorectal infections in men):100 mg, by mouth, twice a day for 7 days. Uncomplicated urethral, endocervical, or rectal infection in adults caused by Chlamydia trachomatis: 100 mg, by mouth, twice a day for 7 days. Nongonococcal urethritis (NGU) caused by C. trachomatis or U. urealyticum: 100 mg, by mouth, twice a day for 7 days.
The dose and frequency of doxycycline for STDs are as follows:
- Gonococcal infections: 100 mg, by mouth, twice a day for 7 days
- Chlamydia trachomatis: 100 mg, by mouth, twice a day for 7 days
- Nongonococcal urethritis: 100 mg, by mouth, twice a day for 7 days 2
From the Research
Dosage and Frequency of Doxycycline for STD Treatment
- The recommended dosage of doxycycline for the treatment of rectal chlamydia is 100 mg twice daily for 7 days 3, 4, 5, 6, 7.
- This dosage and frequency have been compared to azithromycin 1 g single dose in several studies, with doxycycline showing higher efficacy in some cases 4, 5, 7.
- The treatment efficacy of doxycycline 100 mg twice daily for 7 days has been reported to be around 95-100% in some studies 5, 6, 7.
Comparison with Azithromycin
- Azithromycin 1 g single dose is also a recommended treatment for chlamydia, but some studies have raised concerns about its efficacy compared to doxycycline 4, 5, 6, 7.
- A study published in 2019 found that doxycycline had a higher cure rate than azithromycin for rectal chlamydia in women 5.
- Another study published in 2021 found that doxycycline 100 mg twice daily for 7 days was superior to azithromycin 1 g single dose for the treatment of rectal Chlamydia trachomatis infection among men who have sex with men 7.
Clinical Evidence
- The studies cited above provide evidence for the efficacy of doxycycline 100 mg twice daily for 7 days in the treatment of rectal chlamydia 3, 4, 5, 6, 7.
- The results of these studies suggest that doxycycline may be a more effective treatment option than azithromycin for some patients with rectal chlamydia 4, 5, 7.