Can diclofenac be safely given to a patient with a previous history of anaphylaxia and with obstruc

Fråga: Can diclofenac be safely given to a patient with a previous history of anaphylaxia and with obstruction of the throat during acetylsalicylic acid therapy?<br><br>Background: A patient without asthma is hospitalised and needs to be treated with non-steroidal anti-inflammatory drugs (NSAID) due to skeletal metastases. Treatment with steroids was successful for a short period, but was discontinued due to impaired consciousness.

Sammanfattning: Hypersensitivity reactions are often associated with acetylsalicylic acid and non-steroidal anti-inflammatory drugs. A cross-reactivity between these drugs is more frequently seen in patients with asthma, nasal polyps and chronic urticaria. In general, the use of acetylsalicylic acid and NSAIDs should be avoided in asthma patients. In the patient with which this question is concerned, it is recommended to introduce diclofenac under supervision and access to medical equipment in case of a new anaphylactic reaction.

Svar: Anaphylactic reactions during treatment with ASA and other NSAIDs are well known adverse effects (1). Patients with existing asthma and nasal polyps or chronic urticaria have an increased hypersensitivity for aspirin and NSAIDs (2). There is a risk for cross-reactivity in patients treated with aspirin and different NSAIDs and the hypersensitivity develops in about 10 per cent of patients with asthma (3). In addition, acute intolerance to aspirin can develop in patients who have taken the drug for some years without problems (2).<br><br>The features of hypersensitivity include bronchospasm, acute and usually generalised urticaria, angio-edema, severe rhinitis and shock. The reactions may develop within minutes or a few hours after drug intake (2).<br><br>The chemical structures of acetylsalicylic acid and NSAID are not closely related and it is not likely that an immune mechanism causes the cross reactivity (3). Instead, the hypothesis for the asthma hypersensitivity is that an inhibition of the cyclo-oxygenase activity is responsible for the reduced synthesis of prostaglandins from arachidonic acid. This would result in an increased production of bronchoconstrictor leukotrienes that could cause asthma symptoms (2,3).<br><br>Diagnosis of aspirin intolerance is based on oral provocation test (4). However no provocation test for the cross-reactivity between aspirin and NSAIDs is available in medical care.<div id="referenser" style="display:none;">1 Druglinge no 13303 (year )<br>2 Dukes MNG, editor. Meyler´s Side Effects of Drugs. 13th ed. Amsterdamm: Elsevier; 1996<br>3 Davies DM, editor. Textbook of adverse drug reactions. 4th ed. Oxford: Oxford University Press; 1991<br>4 Personal communication with MD Gunnar Bylin, Department of Lung- and Allergy, Huddinge University hospital, Sweden</div>