Treatment of Corynebacterium diphtheria infections

Treatment

Treatment should be started immediately after the clinical diagnosis of diphtheria. Treatment of diphtheria is based on:

1.        Antitoxin therapy and

2.        Antibiotics therapy

◗ Antitoxin therapy

Diphtheria antitoxin: It is the mainstay of therapy in diph-theria. Diphtheria antitoxin is a hyperimmune antiserum produced in horses, which is administered to neutralize the toxin responsible for diphtheria. The antitoxin neutralizes only free toxin before the toxin enters the cells, but is ineffective after toxin has entered into the cell.

The dosage of antitoxin is dependent on the site of infection, patient’s clinical picture, and duration of illness. The antise-rum appears to be more effective in less severely ill patients and in those who are treated earlier in the course of their disease. Therefore, more severely ill patients and those with longer duration of symptoms are given higher doses than those with less severe disease of shorter duration.

      The dosage recommended is 20,000–100,000 U depending on the severity of the infection. The antitoxin is usually adminis-tered by the intravenous route with infusion over 30–60 minutes.

·           Antitoxin appears to be of no value in treatment of cutane-ous diphtheria.

·           The antitoxin is also not recommended for treatment of asymptomatic carriers.

◗ Antibiotics therapy

Antimicrobial therapy is useful in treatment of diphtheria. Antibiotics:

·           Limit the production of toxin,

·           Eradicate diphtheria bacteria from infected hosts, and

·           Prevent transmission of the bacteria to patient contacts.

·           Penicillin and erythromycin are the only antibiotics recommended for treatment. Both antibiotics are equally effective in resolving fever and local symptoms; however, erythromycin has been shown to be marginally superior in eradicating the carrier state.

·           Antibiotic therapy, however, is not a substitute for antitoxin therapy.

·           Elimination of the bacteria is demonstrated by at least two successive negative nose and throat cultures or skin cul-ture obtained 24 hours’ apart, after the completion of the therapy. Treatment with erythromycin is repeated if culture results remain positive.