Ketek (telithromycin), the first in a new family of antibiotics called ketolides, is now available in Canada following its approval by Health Canada. Ketek provides an effective, once-daily and short-term treatment option for a variety of upper and lower respiratory tract infections (RTI).

It is indicated for the treatment of community-acquired pneumonia,acute exacerbations of chronic bronchitis and tonsillitis/pharyngitis. Ketek has an innovative mode of action which has been shown to be effective even with infections caused by bacteria resistant to commonly prescribed antibiotics such as penicillin or macrolides.

"The management of respiratory tract infections, especially in at-risk patients and the elderly, has become extremely challenging," says Dr. Donald E. Low, Microbiologist-in-Chief, Toronto Medical Laboratories/Mount Sinai Hospital and Professor, Department of Medicine and Department of Laboratory Medicine and Pathobiology, University of Toronto. "Patients infected with bacteria resistant to available antibiotics may see their symptoms last longer - leading to failed therapy and second rounds of treatment, thus increasing the risk of inducing resistance," added Dr. Low.

"In most cases, physicians prescribe antibiotics without knowing exactly which bacteria are affecting their patients. By using a targeted spectrum antibiotic such as Ketek, physicians increase the potential of curing their patients once and for all and not having to recommence treatment with a different antimicrobial agent," concluded Dr. Low.

A recent study by the Canadian Bacterial Surveillance Network has shown that the incidence rate of bacteria considered to be "highly" resistant to penicillin increased from 0.9 per cent in 1993 to 7.0 per cent in 2001. The EQUERE (Étude QUEbecoise des pathogènes REspiratoires) study, conducted by Quebec researchers, also showed that the resistance of Streptococcus pneumoniae, the most common pathogen in community-acquired pneumonia, to commonly prescribed treatments was 20.2 per cent. These trends are particularly significant considering that Streptococcus pneumoniae is the leading cause of infectious morbidity and mortality worldwide. Each year in Canada, it accounts for 5,000 cases of bloodstream infections, 700,000 cases of middle ear infection and 12,500 cases of pneumonia requiring hospitalization.

Clinical trials on the efficacy of once-daily Ketek in the treatment of community-acquired pneumonia demonstrated that it is just as effective when compared to other treatments that need to be taken twice or three times daily. In a study involving more than 300 patients suffering from community-acquired pneumonia, 94.6 per cent of patients were cured with a once-a-day, ten-day Ketek treatment, versus 90.1 per cent of those treated with high doses of amoxicillin three times daily. The efficacy of Ketek was comparable to clarithromycin administered twice daily.

Clinical studies with Ketek have shown it to be effective even against those pathogens resistant to penicillin or erythromycin, where the clinical cure rate with Ketek was 71.4 per cent and 60.0 per cent respectively.

"With antibiotic resistance becoming more widespread, Ketek is a valuable treatment option that is both effective and convenient," said Dr. Low.

For patients suffering from acute exacerbations of chronic bronchitis,studies have shown that Ketek, taken once a day for five days, is as effective as commonly used antibiotics taken two to three times daily for 10 days. One study showed that Ketek taken for five days had an 86.4 per cent clinical cure rate, compared with 83.1 per cent for cefuroxime, a common antibiotic, taken for 10 days.

Ketek has also been proven to be effective in the treatment of tonsillitis and pharyngitis. The clinical cure rate for patients in a clinical trial taking Ketek for five days was 92.7 per cent, compared to 91.1 per cent for patients taking clarithromycin for 10 days.

Moreover, Ketek has been shown to have an excellent tolerability profile. Only 3.2 per cent of patients involved in clinical trials discontinued due to adverse events, most of which were mild and transient. In the largest usual care study ever done with antimicrobials, more than 12,000 patients were treated with Ketek. Only 3.8 per cent discontinued due to adverse events. Like other antibiotics, the most common side effects were diarrhea, nausea, dizziness, vomiting and loose stools. Ketek is now available worldwide. It was first launched in October 2001 in Germany and is now approved in all European Union countries, including Spain, Italy and France.

It has also been approved in Japan and in major Latin American countries. To date, four million patients have been treated with Ketek.