A case of two adverse reactions

Low molecular weight heparins are now widely prescribed in the treatment of thromboembolic disease and acute coronary syndromes. Anaphylaxis is a recognised but rare potentially life threatening side effect of heparin. Common clinical features of anaphylaxis are cardiovascular collapse, bronchospasm, cutaneous symptoms, angioedema, generalised oedema, or gastrointestinal symptoms. It is extremely rare, however, for patients to experience such dramatic and potentially life threatening consequences as seen in the case reported here. It has been shown that patients may be tolerant of certain low molecular weight heparins but sensitive to others. Adrenaline is regarded as the most important drug for any severe anaphylactic reaction. Administration by the intramuscular route produces significantly higher peak plasma concentrations compared with subcutaneous injection, which is clearly beneficial in the critically compromised patient. Current UK Resuscitation Council guidelines support the use of 0.5 ml of 1:1000 adrenaline to be administered intramuscularly.