Diphtheria Antitoxin

Uses

This is used for Diphtheria hypersensitivity test, Mild to moderate nasal diphtheria, Mild to moderate tonsillar diphtheria, Mild to moderate pharyngeal or laryngeal diphtheria, Severe diphtheria, Mild to moderate cutaneous diphtheria, Diphtheria hypersensitivity test, Desensitisation of diphtheria hypersensitivity.

Dosage

Diphtheria Antitoxin dosage

Intradermal-

Diphtheria hypersensitivity test:0.1 ml of diphtheria antitoxin (equine) in 0.9% sodium chloride in a 1:100 dilution. Skin test read 20 minutes later. If patient has a history of allergy: 0.05 ml of a 1:1000 dilution. An inj of 0.9% sodium chloride can be used as a control. A positive reaction is represented by an urticarial wheal, with or without pseudopods, with a zone of erythema.

Intravenous-

Mild to moderate nasal diphtheria:10000-20000 units via slow IV infusion.

Mild to moderate tonsillar diphtheria:15000-25000 units via slow IV infusion.

Mild to moderate pharyngeal or laryngeal diphtheria:20000-40000 units via slow IV infusion.

Severe diphtheria:Up to 100000 units by slow IV infusion.

Mild to moderate cutaneous diphtheria:Only used if ulcer >2 cm2(insufficiently absorbed in smaller ulcers). Dose: 20000-40000 units by slow IV infusion.

Subcutaneous-

Desensitisation of diphtheria hypersensitivity:Diphtheria antitoxin (equine) is administered in incremental doses every 15 minutes: 0.05 ml of a 1:20 dilution, 0.1 ml of 1:10 dilution, 0.3 ml of a 1:10 dilution and 0.1 ml of undiluted antitoxin. After another 15 minutes, 0.5 ml of undiluted antitoxin is administered IM or IV.

Side Effects

Serum sickness (type III hypersensitivity reaction) up to 12 days after antitoxin admin, symptoms include: Urticaria, fever, pruritus, malaise, skin rash and arthralgia. Accelerated serum sickness (occurring <7 days after immunisation) may occur in individuals with previous admin of equine serum.

Precaution

History of asthma. Test doses should be administered before immunisation to eliminate hypersensitivity. Adrenaline inj and resuscitation facilities should be available after all immunisation. Not used for diphtheria prophylaxis because of hypersensitivity risk. A negative sensitivity test dose so not completely exclude systemic sensitivity. If hypersensitivity occurs during or immediately after desensitisation procedure, a tourniquet should be applied and adrenaline administered next to the site of inj.

Storage Condition

Store at 2-8° C, do not freeze.

Innovators Monograph

You find simplified version here Diphtheria Antitoxin