Rhabdomyolysis caused by tocolytic therapy with ritodrine hydrochloride

We report a case of rhabdomyolysis with severe generalized weakness and muscle pain after administration of ritodrine hydrochloride, in a pregnant patient without history of neuromuscular disease. Laboratory tests showed an increase of blood CK value and myoglobinuria. An electromyography was performed, revealing a typical myogenic pattern and diffuse denervation activity. Muscular biopsy allowed to rule out inflammatory and metabolic myopathy. After delivery, the patient underwent intensive rehabilitation with progressive improvement of her clinical situation, until complete recovery. Three months later, both neurological assessment and CK levels were normal. This case highlights that rhabdomyolysis has to be considered even in patient treated with ritodrine alone and without history of neuromuscular disease. Therefore, muscular symptoms and CK levels should be monitored in women treated with ritodrine for premature labour.