How effective is Zithromax treatment for chlamydia


Chlamydia trachomatis is the most common sexually transmitted bacterium in developed countries.1 The germs can be detected in every tenth to twentieth young, sexually active adult. Over 300,000 infections per year are expected in this country.2

CLINICAL PICTURE: Chlamydia infections are typically chronic and insidious. Diagnosis is often late or the infection goes undetected because there are no or few signs of the disease.2

In men, serotypes D to K of the obligate intracellularly reproducing bacterium cause up to 50% of all acute non-gonorrheic urethritis, which can be accompanied by painful urination and discharge from the urethra, and at least a third of all acute epididymis.3 In women, the ascending infection causes inflammation of the cervix, endometrium and fallopian tubes.4 Infectious arthritis in men and women can be traced back to C. trachomatis infections.3

Women become infected more easily than men when having unprotected intercourse with an infected partner (40% vs. 20% risk). The infection is more often asymptomatic in women (up to 75% vs. 20%), but they carry a higher risk of serious consequential damage.5 Inflammation of the fallopian tubes can result in sterility or ectopic pregnancy. After an infection, over 10% of those affected are sterile, after three episodes of infection more than half.

DIAGNOSIS: The enzyme immunoassay reveals 80% to 90% of the germ in the infected urethral or cervical swab.6 Fluorescence tests or cultures are more sensitive, but more complex.6,4

SCREENING: Newborns from infected mothers can become infected during birth, often resulting in inclusion conjunctivitis or pneumonia.6 Screening of as many pregnant women as possible for chlamydial antigen is therefore recommended.2 In Sweden, infection rates have been cut in half since a comprehensive general screening program was introduced in the early 1980s.6

TREATMENT: The drug of choice is doxycycline (VIBRAMYCIN, etc.): 100 mg twice a day for at least seven4 to ten2 days (cf. a-t 2 [1994], 19). Alternatively, 500 mg erythromycin (ERYTHROCIN, etc.) can be taken twice a day. The macrolide is also suitable for pregnant and breastfeeding women.6 In the case of erythromycin intolerance, amoxicillin (AMOXYPEN and others; 500 mg three times a day) can also be considered during pregnancy.7 Chronic diseases with inflammation of the adnexa, epididymis etc. should be treated for 20 days. Infectious arthritis can require up to three months of therapy.2

The newer macrolide azithromycin (ZITHROMAX) is characterized by high tissue levels and an elimination half-life from the tissues of two to four days.8,9 In a controlled comparison, a single dose of 1 g is just as effective as the seven-day doxycycline regimen for chlamydial urethritis and cervicitis.9 The advantage of easier intake is offset by the up to four times higher costs (see box).

It is advisable to also examine sexual partners and, if necessary, treat them.

CONCLUSION: Genital Chlamydia trachomatis infections are one of the most common STDs. The chronic, insidious infections are often recognized late or not at all. Doxycycline (VIBRAMYCIN, etc.) is the drug of choice. In the event of intolerance or during pregnancy and breastfeeding, erythromycin (ERYTHROCIN, etc.) can be considered. The macrolide azithromycin (ZITHROMAX) enables uncomplicated chlamydia infection - albeit more expensive - single-dose treatment.