Australian Regenerative Medicine Institute

Postinfectious Cough: Research

In the case of proven or presumed pertussis infection, prospective clinical trials have shown that treatment with erythromycin (or trimethoprim/sulfamethoxazole when a macrolide cannot be given) is necessary; the recommended dose is 40 to 50 mg/ kg/d in children and 1 to 2 g per day in adults for 2 weeks. Therapy should begin as soon as the disease is suspected and should not be delayed until confirmation of the diagnosis, as early therapy during the catarrhal phase (ie, the first 2 weeks) will rapidly clear B pertussis from the nasopharynx and decrease the coughing paroxysms and other compli-cations. Patients with active cases should be isolated at home and away from work or school for 5 days after therapy with antibiotics is started.

There is some evidence that therapy given in the paroxysmal phase may be effective, but it is usually of limited benefit. Erythromycin resistance has been reported but is quite rare (< 1%). Newer macrolides such as clarithromycin and azithromycin are also active against B pertussis and have a better side-effect profile. Until the past few years, only small clinical trials have been available to support their use. In a large multicenter randomized trial, azithromycin was found to be as effective as erythromycin estolate in the treatment of pertussis in children with much better compliance because of a better side-effect profile. The newer fluoroquinolones also show good in vitro activities against B pertussis, but there are no clinical trials to support their use. Prophylaxis for exposed persons has been found to be effective in decreasing the severity and transmission of the disease to others if therapy is begun early (ie, within the first 2 weeks of the infection).

The benefits of adding long-acting (3-agonists, antihistamines, corticosteroids, and pertussis Ig have been studied in pertussis infection. No significant benefit has been found with any of these interventions in controlling the paroxysms of coughing. Results of trials in adults and children using acellular pertussis vaccines rather than whole cell vaccines suggest that in the future, pertussis may be safely and effectively prevented in all age groups. In the past pertussis vaccines have been approved only for children under age seven and a series of 5 doses (coupled with diphtheria and tetanus toxoid) is recommended before the 7th birthday.

Category: Respiratory Symptoms

Tags: Bordetella pertussis, pertussis infection, postinfectious cough, postviral cough