RILUZOLE CAUSING PANCYTOPENIA: A CLINICALLY IMPORTANT RARITY

Design Case Report: An 83-year-old lady, was admitted with progressive speech and swallowing difficulty and wasting of small muscles of hand for 3 months. EMG revealed widespread anterior horn cell disease. With a diagnosis of MND, She was started on Riluzole 50 mg, LFT and FBC were normal before and 2 days after 1 st dose and the dose increased to a recommended dose of 50 mg twice a day. While waiting for PEG tube insertion, within 7 days, FBC showed a significant drop in Hb of 23 g/L ( from 125 to 102 g/L), Platelet dropped to 150×x10^9/L from 208 × 10^9/L, leucopenica ( 2.4 × 10^9/L) without any significant neutropenia. Her follow up haemogram showed persistent pancytopenia with more evident leucopenia and thrombocytopenia over next 7 days. She had no symptoms and signs of infection with normal infection screen. Her medication history was unremarkable apart from riluzole and thyroxine. No past history of liver disease or haematological conditions. Serum electrophoresis, Vitamin B12 and Folate were completely normal. A diagnosis of riluzole induced pancytopenia was made. A study by FDA suggests out of 861 patients, 3 patients (0.35%) developed Pancytopenia and 100% of them had it in the 1 st month. The aim of this case report to highlight the importance of considering Pancytopenia as an adverse reaction of riluzole. Patient may develop overt sepsis as a part of the spectrum. In that case, risk and benefit of riluzole prescription needs to addressed as an individual case basis.