Are there influenza-like reactions, vomits or syncope described due to treatment with oral preparat

Fråga: Are there influenza-like reactions, vomits or syncope described due to treatment with oral preparations of vitamin B12?

Clinical background: An 80-year-old woman with vitamin B12 deficiency has for two years been treated with injection Behepan (1.0 mg/ml), one ml, and has several times had an influenza-like reaction a couple of hours after injection. One week ago she had a new injection and reacted with vomiting and syncope 2.5 hours after injection. The questioner wants to change to oral treatment with tablet Behepan or tablet Betolvex. Are there similar reactions reported for these oral preparations?

Sammanfattning: We have done a thorough literature search in Medline, Drugline, pharmacological handbooks and the Swedish Adverse Drug Reactions Advisory Committee (SADRAC). Both cyanocobalamine and hydroxocobalamine administration (unspecified route) have caused allergic hypersensitivity reactions (1). Anaphylactic reactions, including shivering, bronchospasm, dyspnea, urticaria, have followed intramuscular injections of cyanocobalamin (2). Some of these symptoms could possibly be understood as influenza-like reactions. However, we have found no documentation supporting a relationship between treatment with cyanocobalamine or hydroxocobalamine (Behepan, Betolvex) and vomits or syncope. It could not be excluded that peroral administration could give rise to influenza-like reactions as mentioned in the present case.

This case should be reported to SADRAC.

Svar: Se sammanfattning/konklusjon. 1 Reynolds JEF, editor. Martindale, The extra pharmacopoeia. 31st ed. London: Royal Pharmaceutical Society; 1996 2 Dollery C Sir, editor. Therapeutic drugs. 1st ed. Edinburgh: Churchill Livingstone; 1990. p. D11-D17