SHORT COMMUNICATION Elena Balları´n Æ Luisa Iba´n˜ez Æ Jose´-Angel Herna´ ndez Lluı´s Force Æ Joan-Ramon Laporte Cyanamide-induced aplastic anemia Received: 28 January 2005 / Accepted: 4 May 2005 / Published online: 1 July 2005 Ó Springer-Verlag 2005 Abstract Objective: To report a case of aplastic anemia in a patient treated with cyanamide, an alcohol-aversive drug. Case summary: A 67-year-old man was admitted to hospital because of fever and pancytopenia. He had ta- ken cyanamide for 6 months as an alcohol deterrent. No other risk factors for aplastic anemia were identified by interviewing the patient using a structured validated questionnaire. The results of bone-marrow biopsy showed severe aplastic anemia. Cyanamide was discon- tinued and the patient was treated according to a pre- specified treatment protocol. One year after hospital admission, the patient was completely recovered with no need of immunosuppressive therapy. An objective cau- sality assessment revealed that an adverse drug reaction was probable. Discussion: As the efficacy of cyanamide has been ques- tioned, due to the failure of various trials to show any benefit over placebo, its overall benefit/risk ratio should be reconsidered. The complete and rapid hematological recovery after discontinuation of the drug, and the ab- sence of other factors that could explain the condition support the association of the present case of aplastic anemia with cyanamide. The mechanism remains un- known. Aplastic anemia is a rare but potentially serious adverse drug effect of cyanamide treatment. Conclusions: Given the poor evidence on the efficacy of cyanamide and the associated risk of aplastic anemia, its use in reducing alcohol consumption should be recon- sidered. Keywords Cyanamide Æ Aplastic anemia Æ Pharmacovigilance Æ Adverse drug reaction Introduction Cyanamide is an alcohol-sensitizing drug. Like disulfi- ram, it inhibits the liver enzyme aldehyde dehydrogenase (ALDH), causing an increase in blood acetaldehyde le- vel after ethanol ingestion. Increased concentrations of acetaldehyde cause flushing, tachycardia, tachypnea, feeling of warmth, palpitations, and shortness of breath. Inhibition of ALDH is maximal 1–2 h after cyanamide administration and lasts up to 24 h. The severity and duration of symptoms depend on the dose of the drug and the amount of ethanol in the body. Cyanamide is approved in Austria, Ireland, and Spain. It is used as a conditioning method to help moti- vate alcoholics to give up drinking. Its efficacy is being questioned because several trials have failed to show any benefit over placebo [1–3]. Various adverse drug effects have been described, such as peripheral neuropathy [4], hepatocyte inclusion bodies [5], liver dysfunction [6], hypoxia with hypotension [7], agranulocytosis [8, 9], and aplastic anemia [10, 11]. We report a case of aplastic anemia in a patient treated with cyanamide. Case report A 67-year-old man with a history of severe chronic alco- holism, lumbar sympathectomy, and chronic obstructive lung disease was admitted because of fever and pancyto- penia. His blood count showed hemoglobin 92 g/l; platelets 114·10 9 /l; leukocytes 0.72·10 9 /l with neutrophil count <0.1·10 9 /l and eosinophils 0.14·10 9 /l; corrected reticulocytes 0.45%. Biochemical parameters, Ham’s test, cloned study of paroxysmal nocturnal hemoglobinuria E. Balları´n (&) Æ L. Iba´n˜ez Æ J.-R. Laporte Fundacio´ Institut Catala` de Farmacologia Servei de Farmacologia Clı´nica, Hospital Universitari Vall d’Hebron Universitat Auto`noma de Barcelona, P Vall d’Hebron 129-139, 08035 Barcelona, Spain E-mail: eb@icf.uab.es Tel.: +34-93-489-4125 Fax: +34-93-489-4109 J.-A. Herna´ndez Hematology Department, Hospital de Mataro´, Mataro´, Spain L. Force Internal Medicine Department, Hospital de Mataro´, Mataro´, Spain Eur J Clin Pharmacol (2005) 61: 467–469 DOI 10.1007/s00228-005-0954-1