A Case of Codeine Induced Anaphylaxis via Oral Route.

Abstract

Codeine is widely prescribed in clinical settings for the relief of pain and

non-productive coughs. Common adverse drug reactions to codeine include

constipation, euphoria, nausea, and drowsiness. However, there have been few

reports of serious adverse reactions after codeine ingestion in adults. Here, we

present a case of severe anaphylaxis after oral ingestion of a therapeutic dose

of codeine. A 30-year-old Korean woman complained of the sudden onset of dyspnea,

urticaria, chest tightness, and dizziness 10 minutes after taking a 10-mg dose of

codeine to treat a chronic cough following a viral infection. She had previously

experienced episodes of asthma exacerbation following upper respiratory

infections, and had non-atopic rhinitis and a food allergy to seafood. A skin

prick test showed a positive response to 1-10 mg/mL of codeine extract, with a

mean wheal size of 3.5 mm, while negative results were obtained in 3 healthy

adult controls. A basophil histamine release test showed a notable dose-dependent

increase in histamine following serial incubations with codeine phosphate, while

there were minimal changes in the healthy controls. Following a CYP2D6 genotype

analysis, the patient was found to have the CYP2D6*1/*10 allele, indicating she

was an intermediate metabolizer. An open label oral challenge test was positive.

To the best of our knowledge, this is the first report of a patient presenting

with severe anaphylaxis after the ingestion of a therapeutic dose of codeine,

which may be mediated by the direct release of histamine by basophils following

exposure to codeine.