Could lengthening minocycline therapy better treat early syphilis?

Abstract

Syphilis is a sexually transmitted disease caused by Treponema pallidum. Minocycline, a representative tetracycline derivative, has the greatest antimicrobial activity among all tetracyclines. There are few reports about treating syphilis with minocycline because there is a lack of efficacy data from controlled trials. We compared the rates of serological cure in patients with early syphilis who were treated with minocycline or benzathine penicillin G (BPG).During the study period, a total of 40 syphilis patients received the BPG treatment, which was a single intramuscular dose of 2.4 million units of BPG, and 156 patients were treated with minocycline; 77 patients were placed in the 2-week, standard minocycline therapy group and received 100 mg of minocycline orally, twice daily for 14 days, and 79 patients were placed in the 4-week, lengthened minocycline therapy group and received 100 mg of minocycline orally, twice daily for 28 days. The outcome of interest was the rate of serological cure in these patients.At the end of the 2-year follow-up, the serological cure rate of the 4-week, lengthened minocycline therapy group (87.34%) was higher than that of both the 2-week, standard minocycline therapy group (72.73%) and the BPG treatment group (77.50%). In addition, the curative effect of the 4-week, lengthened minocycline therapy was significantly greater than that of the 2-week, standard minocycline therapy in patients who were aged >40 years; exhibited an initial rapid plasma reagin titer ≥1: 32; or exhibited secondary syphilis (P = 0.000, 0.008, 0.000; <0.05).Minocycline appears to be an effective agent for treating early syphilis, especially when applied as a 4-week, lengthened therapy.

Efficacy of minocycline in the treatment of early syphilis

“…Our study compared the efficacy of minocycline in the treatment of syphilis and found that the treatment effect of minocycline was similar to that of benzathine penicillin. Shao et al 17 reported that after the two years follow-up, the serological cure rate of the minocycline four week treatment group (87.34%) was even slightly higher than that of benzathine penicillin (77.50%). Besides, studies have been carried out that an oral loading dose of 200 mg of minocycline, followed by 100 mg twice daily for 15 days, was the treatment for syphilis patients, and as a result, all patients had satisfactory responses to serological tests during followup for as long as one year; in this study, the drug was well tolerated and no major unpleasant side effects were noted.…”

“…Thus, we suspected that primary syphilis was also sensitive to the treatment of minocycline. Moreover, Shao et al 17 compared different courses of minocycline treatment and found that the serological cure rate of minocycline four week treatment (87.34%) was superior to that of minocycline two week treatment (72.73%). At present, there are few studies on the treatment of syphilis with minocycline, which means the further research and evaluation of minocycline efficacy still need to be observed.…”

Malignant syphilis accompanied with neurosyphilis in a malnourished patient: A case report

“…Some authors recommend increasing the dose in cases of poor general health conditions. For resistant cases or relapses, prolonged therapy with high doses of penicillin is suggested[20]. In the present case, the patient was diagnosed with malignant syphilis accompanied with neurosyphilis, and he was initially treated with 60 million units of penicillin daily for 10 d, in view of the fact that crystalline penicillin was able to cross the blood-brain barrier.…”

An Unusual Clinical Presentation of Cutaneous Syphilis

“…While intramuscular 2.4 million units benzathine penicillin G single dose remains the gold standard of treatment, minocycline has been shown to be an effective alternative therapy for early syphilis if penicillin is unavailable. 5…”