- Differential Diagnosis
Drug Information for Pharmalgen (ALK-Abello A S): Adverse Reactions
- Clinical Pharmacology 1
- Indications and Usage
- Adverse Reactions
- Dosage and Administration
- How Supplied
- PRINCIPAL DISPLAY PANEL
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Severe anaphylactic reactions to this extract can occur in extremely allergic patients and at any dosage level. Do not use this extract unless you are prepared to deal with these reactions, and until you have read and understood the Warnings, Precautions, and Dosage and Administration sections of this insert.
The most serious systemic reaction that can occur is anaphylactic shock, which, while rare, is life threatening and must be treated immediately. Among other systemic reactions that have occurred are laryngeal edema, fainting, pallor, bradycardia, hypotension, bronchospasm, angioedema, cough, sneezing, conjunctivitis, rhinitis, and urticaria.
Should a serious systemic reaction occur:
- Inject 0.3 – 0.5 ml of 1:1000 epinephrine into the opposite arm; this may be repeated every 5 to 10 minutes, as a succession of smaller doses is more effective and less dangerous than a single larger one. Use a smaller dose for infants and children, in the range of 0.01 ml/kg of body weight.
- Apply a tourniquet proximal to the injection site; loosen it at least every 10 minutes.
- Inject no more than 0.1 ml of 1:1000 epinephrine at the injection site, to delay the absorption of the remaining extract.
These measures will almost always reverse the reaction, but in the rare instances when they do not, then the full armamentarium of emergency medicine may be required, among them: direct laryngoscopy, direct current cardioversion, tracheotomy, and intracardiac injection of drugs8.
The occurrence of a severe systemic reaction to an injection of this extract does not contraindicate further therapy, but the next dose given should be reduced by at least 90%, and raised very slowly thereafter. If a pattern of systemic reactions – even very mild ones – appears, then the benefits of continued treatment must be carefully weighed against the substantial demonstrated risk.
Local reactions, even relatively severe but transient redness, swelling and discomfort, are the normal physiologic response to the allergens and to the volume of the fluid injected, and in their milder form is evidence of the effectiveness of the therapy. Local reactions generally subside quickly and do not require treatment, but application of cold to the injection site or other symptomatic measures may be useful.
However, severe local reactions should be considered a warning of potential systemic reaction if that dosage is continued. Always reduce the dose substantially if such a local reaction occurs.
See Adverse Reactions section.
- Drug Information Provided by National Library of Medicine (NLM).