In spite of years passing, an only injection of penicillin remains the preferred treatment against syphilis in its starting stage, since its alternative (oral doxiciclin) needs treatments lasting various weeks and then affects the patient’s compliance to therapy. With a multinational, randomized, but not blinded, trial, 517 pregnant women not affected by HIV, but by syphilis in its primary, secondary or starting asymptomatic stages, have been treated with benzathine penicillin G (2.4 million units administered in 2 intramuscular injections) or azithromycin (2 g, taken in 4 tablets of 500 mg). After 6 months, about 75 % of patients in each group were judged as recovered according to a rapid test performed on diluted plasma. 4 women, instead, presented a therapeutical failure shown by the positivity of the above mentioned test, and all the 4 belonged to the azithromycin group. Side effects, above all gastrointestinal ones, were more frequent with the macrolide.
Azithromycin oral monodose is no doubt a therapeutical attraction in case of syphilis: it is well tolerated, it is easy to take, it is active also against Chlamydia and Neisseria. Some doubts on the use of the macrolide however remain: its efficacy during pregnancy, the lack of action against HIV, the onset of rapid mutations with a consequent antibiotic resistance by Treponema.
