Reactions 979 - 29 Nov 2003

★ SRiluzole

First report of extrinsic allergic alveolitis in anelderly patient: case report

A 69-year-old man developed extrinsic allergic alveolitiswhile receiving riluzole for sporadic amyotrophic lateralsclerosis.

The man had been receiving riluzole 50mg twice daily for21 months when he presented with a 3-month history ofincreasing and disabling dyspnoea and dry cough. He had alsoreceived omeprazole for oesophagitis for > 10 years, butswitched to lansoprazole 10 days before the onset ofrespiratory symptoms. He received antibacterials for 20 dayswith no improvement before being diagnosed with pulmonaryfibrosis. He then received an 8-week tapering course ofmethylprednisolone with improvement in his generalcondition, but little effect on his coughing and dyspnoea, andhis symptoms recurred when methylprednisolone wasstopped.

On examination, the man had an increased respiratory rateand investigations revealed hypoxia, an erythrocytesedimentation rate of 63 mm/h and a lactic dehydrogenaselevel of 701 U/L. A chest x-ray was suggestive of interstitiallung disease, and lung function measurements showedrestrictive lung disease and a severe decrease in carbonmonoxide diffusion. Chest CT showed enlargement of theinterlobular septa and bronchial structures, andbronchoalveolar lavage fluid contained 358 leucocytes/µL, ofwhich 51.5% were lymphocytes. An open lung biopsyspecimen showed an interstitial mononuclear infiltrate andloose epithelioid granulomas, characteristic of hypersensitivitypneumonitis.

Riluzole and lansoprazole were discontinued and the manreceived methylprednisolone. Three weeks later, his dyspnoeahad improved and his cough had resolved. His arterial bloodgas had normalised, a chest x-ray and CT scan showedsignificant resolution, his lung function showed partialrecuperation and his carbon monoxide diffusion improvedsignificantly.

Author comment: "Omeprazole compromises the effectof riluzole by enhancing its metabolization. . . Lansoprazoledoes not have this effect. We hypothesis that the deleteriouseffect of riluzole in this patient only became apparent afterswitching omeprazole to lansoprazole, because this switchpreceded the onset of symptoms in our patient by only10 days. The prior 21 months of exposure to riluzole +omeprazole may have allowed the patient to develop asubclinical reaction to riluzole."Cassiman D, et al. Hypersensitivity pneumonitis possibly caused by riluzoletherapy in ALS. Neurology 61: 1150-1151, No. 8, 28 Oct 2003 -Belgium 800958103

» Editorial comment: A search of AdisBase and Medline didnot reveal any previous case reports of allergic alveolitisassociated with riluzole. The WHO Adverse Drug Reactionsdatabase contained one report of allergic alveolitis associatedwith riluzole.

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Reactions 29 Nov 2003 No. 9790114-9954/10/0979-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved