Pharmacology Update
Trovafloxacin Tablet and Azithromycin for Oral Suspension
By William T. Elliott, MD, FACP and James Chan, PharmD, PhD
In december, the FDA approved a product for the dual treatment of two common sexually transmitted diseases caused by Neisseria gonorrhea and Chlamydia trachomatis. Marketed by Pfizer under the trade name Trovan/Zithromax Compliance Pak, the combination contains a fluoroquinolone, trovafloxacin, and an azalide, azithromycin.
Indications
Trovafloxacin/azithromycin is indicated for the treatment of uncomplicated urethral gonorrhea in males and endocervical and rectal gonorrhea in females caused by N. gonorrhea and nongonococcal urethritis and cervicitis due to C. trachomatis.
Dosage
The contents of the azithromycin (1 g) packet should be mixed thoroughly with 2 oz of water and taken orally. This should be followed by an additional 2 oz of water to ensure that the complete packet is consumed. The trovafloxacin tablet should be taken with the second portion of the liquid. The product may be taken without regard to meals but should be taken at least two hours before or two hours after aluminum- or magnesium-containing antacids, sucralfate, citric acid/sodium citrate, formulations containing buffers such as didanosine, or metal cations such as iron.
Patients should refer their sex partners for evaluation, testing, and treatment. Patients should be instructed to abstain from sexual intercourse for seven days after a single-dose regimen.1
Trovan/Zithromax is supplied as a 100 mg tablet of trovafloxacin and 1 g azithromycin for oral suspension.
Potential Advantages
The Trovan/Zithromax Compliance Pak provides a convenient single-dose dual therapy for gonococcal and chlamydial infections. Trofloxacin has shown in vitro activity against strains of N. gonorrhea that are relatively resistant to ciprofloxacin and ofloxacin.3 Single-dose azithromycin is more convenient than doxycycline, which is dosed for seven days and may actually be cost-effective despite higher initial drug cost.5
Potential Disadvantages
Quinolones are contraindicated for pregnant women.1
Most common side effects associated with the combination of trovafloxacin and azithromycin include nausea (50%), abdominal pain (25%), and dizziness/lightheadedness (15%).3 Although rare (< 1%) in the United States, N. gonorrhea resistant to fluoroquinolones has been reported in other parts of the world, especially in Asia.1 The prevalence of quinolone-resistant N. gonorrhea is expected to increase in the United States.1
Comments
Routine dual treatment for N. gonorrhea and C. trachomatis is generally recommended, as coinfection is common. Dual treatment may also hinder the development of resistant strains of N. gonorrhea since both doxycycline and azithromycin are active against N. gonorrhea.1 Current recommendations of the CDC for dual treatment include azithromycin or doxycycline for chlamydia and ceftriaxone 125 mg IM, cefixime 400 mg, ciprofloxacin 500 mg, or ofloxacin 400 mg1 for gonorrhea. Azithromycin single dose is more convenient than doxycyline 100 mg twice daily for seven days. Single-dose trovafloxacin has been reported to be equivalent to ofloxacin both bacteriologically and clinically.4 Cure rate was 99% for trovafloxacin and 98% for ofloxacin. This compares favorably to ceftriaxone (99%), ciprofloxacin (99.8%), and cefixime (97%).1
At the time of this printing, Pfizer has not yet launched the product and cost was not available.
Clinical Implications
Chlamydial and gonorrheal genital infections are common in the United States and often exist as coinfections. Chlamydial infections are commonly asymptomatic in both males and females, while gonorrhea tends to be asymptomatic in females. Notwithstanding transmission, serious sequelae can result from these infections, including pelvic inflammatory disease, ectopic pregnancy, and infertility. To ensure compliance, medications should be dispensed on site at the time of diagnosis and the administration of the medication should be directly observed. Currently, there are convenient and highly effective dual treatments. Trovan/Zithromax Compliance Pak offers a single-prescription, oral, one-time treatment that is highly effective. Patients do not need to be retested for cure after completing treatment unless symptoms persist or reinfection is suspected. (Dr.
Elliott is Chair, Pharmacy Education, California Division of Kaiser Permanente; and Assistant Clinical Professor of Medicine, University of California-San Franscisco. Dr. Chan is Pharmacy Quality and Outcomes Manager, Kaiser Permanente, Oakland, CA.)
References
1. MMWR 1998;47(RR-1):1-118.
2. Knapp JS, et al. Antimicrob Agents Chemother 1995;39(4):987-989.
3. Trovan/Zithromax Product Information. Pfizer 1999.
4. Jones RB, et al. Am J Med 1998;104:28-32.
5. Magid D, et al. Ann Intern Med 1996;124(4):389-399.
The combination of trovafloxacin and azithromycin:
a. is indicated for chlamydia and gonorrhea, respectively.
b. is effective in males only.
c. is indicated for pregnant women with cervicitis.
d. has been found to be effective in treating cervicitis and urethritis, yet is not approved for treatment of pelvic inflammatory disease.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content