The patient has to be given treatment immediately after the disease is suspected. A delay in treatment can result in death or long-term heart disease. In severe cases there is obstruction of the throat, which may require intubation or a tracheostomy.

Diphtheria antitoxin should be administered through an injection via a vein and this is called intravenous or IV injection. This will fight the diphtheria poison. But first, doctors may perform skin allergy tests to make sure that the infected person doesn't have an allergy to the antitoxin.

Antibiotics are used in patients or carriers to eradicate C. diphtheriae and prevent its transmission to others. The recommended antibiotics are:

 Erythromycin (40 mg/kg per day with a maximum of 2 g/d) that is given orally or by injection for 14 days is recommended.

 Procaine Penicillin G given intramuscularly for 14 days.

Patients with allergies to Penicillin G or Erythromycin can use Rifampin or Clindamycin.

If the infection is advanced, people with diphtheria may need a ventilator to help them breathe. In cases in which the toxins may have spread to the heart, kidneys, or central nervous system, patients may need intravenous fluids, oxygen, or heart medications.

Immediate hospitalization and early intervention allow most patients to recover from diphtheria without any problem. Last but not the least a strict bed rest for 4 to 6 weeks or until full recovery is recommended.

Those who have recovered should still receive a full course of the diphtheria vaccine to prevent a recurrence because contracting the disease doesn't guarantee lifetime immunity.