The effect of methylphenidate (Ritalin) on post-halothane muscular spasticity.

Methylphenidate, a psychomotor stimulant with a weak sympathomimetic action, completely suppresses the muscular spasticity and tremor which may occur during the recovery from halothane anaesthesia. It is suggested that the spasticity is due to the recovery of spinal reflex activity before the upper motor neurones have recovered from the inhibition of anaesthesia and that methylphenidate acts by stimulating the midbrain reticulum. The adrenergic overactivity of the heart which is provoked by methylphenidate is prevented by small doses of a beta-blocking drug and by neostigmine.