Although antibiotics were effective in eliminating B. pertussis, they did not alter the subsequent clinical course of the illness. There is insufficient evidence to determine the benefit of prophylactic treatment of pertussis contacts.

Antibiotics are effective in eliminating B. pertussis from patients with the disease, rendering them non-infectious, but do not alter the subsequent clinical course of the illness. Effective regimens include: three days of azithromycin, seven days of clarithromycin, seven or 14 days of erythromycin estolate, and 14 days of erythromycin ethylsuccinate. Considering microbiological clearance and side effects, three days of azithromycin or seven days of clarithromycin are the best regimens. Seven days of trimethoprim/sulfamethoxazole also appeared to be effective for the eradication of B. pertussis from the nasopharynx and may serve as an alternative antibiotic treatment for patients who cannot tolerate a macrolide. There is insufficient evidence to determine the benefit of prophylactic treatment of pertussis contacts.

BackgroundWhooping cough is a highly contagious respiratory disease. Infants are at highest risk of severe disease and death. Erythromycin for 14 days is currently recommended for treatment and contact prophylaxis but its benefit is uncertain.ObjectivesTo assess the risks and benefits of antibiotic treatment of and contact prophylaxis against whooping cough in children and adults.Search methodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL Issue 4, 2010), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, the Database of Abstracts of Reviews of Effects (DARE Issue 4, 2010), MEDLINE (1966 to January Week 1, 2011) and EMBASE (1974 to 18 January 2011).Selection criteriaRandomised controlled trials (RCTs) and quasi‐RCTs of antibiotics for treatment of and contact prophylaxis against whooping cough in children and adults.Data collection and analysisThree to four review authors independently extracted data and assessed the quality of each trial.Main resultsThirteen trials with 2197 participants met the inclusion criteria: 11 trials investigated treatment regimens; two investigated prophylaxis regimens. The quality of the trials was variable. For eradicating Bordetella pertussis (B. pertussis) from the nasopharynx, short‐term antibiotics (azithromycin for three to five days, or clarithromycin or erythromycin for seven days) were as effective as long‐term (erythromycin for 10 to 14 days) (risk ratio (RR) 1.01; 95% confidence interval (CI) 0.98 to 1.04), but had fewer side effects (RR 0.66; 95% CI 0.52 to 0.83). Trimethoprim/sulphamethoxazole for seven days was also effective. Nor were there differences in clinical outcomes or microbiological relapse between short and long‐term antibiotics. For preventing infection by treating contacts older than six months of age, antibiotics did not significantly improve clinical symptoms, nor the number of cases developing culture‐positive B. pertussis. Side effects were reported with antibiotics and they varied from one antibiotic to another.Authors' conclusionsAlthough antibiotics were effective in eliminating B. pertussis, they did not alter the subsequent clinical course of the illness. There is insufficient evidence to determine the benefits of prophylactic treatment of pertussis contacts.Plain Language SummaryAntibiotics for whooping cough (pertussis)Whooping cough is a highly contagious disease caused by pertussis bacteria and may lead to death, particularly in infants less than 12 months of age. Although it can be prevented by routine vaccination, it still affects many people. Thirteen trials involving 2197 participants were included in this review. We found that several antibiotic treatments were equally effective in eliminating the bacteria infecting patients, but they did not alter the clinical outcome. There was insufficient evidence to decide whether there is benefit for treating healthy contacts. Side effects were reported with antibiotics and they varied from one antibiotic to another. The result of the review should be interpreted with caution since this review is based on a limited number of trials and some of these trials involved small numbers of participants.