The drug, named Zmax (azithromycin prolonged release), is an oral suspension manufactured by Pfizer. It makes use of microsphere therapy to deliver a complete course of antibiotic treatment in a single two-gram dose.
In the first 24 hours after taking the drug, the amount of medicine that gets into the tissue is much higher than a standard dose of other antibiotics. This "front loading" of azithromycin prolonged release provides high drug level earlier in the course of the infection when the bacterial load is likely to be highest.
The microsphere technology allows for release of the medicine in the small intestine rather than in the stomach, which results in a favorable side effect profile.
During the course of the studies, the most common treatment-related adverse reactions in adult subjects receiving a single, two-gram dose were diarrhea, nausea, abdominal pain, headache and vomiting. In the majority of azithromycin prolonged release treated patients, diarrhea resolved within two days.
The one-dose antibiotic is indicated for the treatment of susceptible strains of bacteria for mild to moderate respiratory tract infections, acute bacterial sinusitis (ABS) and community-acquired pneumonia. Other recent studies showed that the antibiotic is also effective in treating emphyzema, typhoid fever and malaria.
"A single, high-dose antibiotic is a breakthrough in the treatment of infections with the average Filipino patient prone to stopping medication even before full recovery," said Dr. Camilo Roa, past president of the Philippine College of Chest Physicians during the press launch of the antibiotic at the Shangri-La Edsa hotel.
"Taking only one pill will greatly minimize expenses of the patients compared with other antibiotics that must be taken for seven to 10 days. A treatment taken just once can address compliance issues and may minimize the emergence of antibiotic resistance," he added.
Dr. Roa also explained that the efficacy of most antibiotic therapies is usually affected by two situations: Misuse of the medicines, and rise of medicine-resistant microbes.
Misuse usually occurs when an antimicrobial is used indiscriminately even in conditions where it is not needed. Other forms of abuse include incomplete days of dosing (deliberate or not), substitution with lower milligram or inferior formulation, failure to follow medicine with food intake instructions, and self-medication.
While some microbes are naturally resistant to certain antibiotics, most of the resistant strains likely result from inappropriate antibiotic usage.
Ineffectivity of an incorrect antibiotic regimen results to microbes "adapting" to the presence of the antibiotic which can later evolve and produce mechanisms that will eliminate or neutralize the effects of the medicine.
Inability to follow the drug-dosing schedule could also be due to a complicated dosing schedule. Studies done in different countries have shown that more frequent dosing and longer medicine intake leads to poorer compliance.
The short dosing regimen of Zmax promotes 100 percent compliance among patients since it is only taken in one dose, helping them complete the course of treatment. Its cost effectiveness (with price range of about
