20-year-old man developed an acute dystonic reaction following the selfadministrationof ketamine. The episode resolved upon treatment with ch’phenhydramine. Dystonia is an unusual toxic effect of ketamine abuse; potential mechanisms for its occurrence in this instance are discussed.
[Felser JM, Orban DJ: Dystonic reaction after ketamine abuse. Ann Emerg Med 11:673-675, December 1982.]
INTRODUCTION
Ketamine, an intravenous general anesthetic chemically related to phencyclidine,has recently gained attention because of its abuse potential, especially on the West Coast. 1 We report a case of drag-induced dystonia that occurred after the self-administration of ketamine. Dystonia is an unusual adverse effect of ketamine, and mechanisms possibly responsible in this instance are discussed.
CASE REPORT
A 20-year-old man self-administered 0.5 cc of ketamine intravenously. Syringes, needles, and ketamine were obtained from a nearby veterinary hospital. No other drugs were concomitantly administered, and the patient had used ketamine before. Ten hours later, the patient presented to the UCLA Emergency Medicine Center after noting five episodes of sustained abnormal tongue and neck movements that interfered with speech. The last of these began one hour prior to arrival. At no time was generalized motor activity or loss of consciousness noted. The patient denied history of previous neurologic abnormalities.
Physical examination revealed an anxious but healthy-appearing man who was afebrile with stable vital signs including temperature, 37 C; blood pressure, 140/90 mm Hg; pulse, 86; and a respiratory rate of 18. Neurologic exam revealed equal and reactive pupils at 5 ram. The tongue was protruded and deviated to the left side and the neck was held in extension while deviated to the left. The patient was unable to speak, yet he was alert and able to communicate in writing. Deep tendon reflexes were 2+ and symmetric throughout; plantar responses were flexor bilaterally.
Serum chemistry studies included sodium, 140; potassium, 4.4; chloride, 107; bicarbonate, 24~ glucose, 108; BUN, 22; and calcium, 9.5. Urinalysis was unremarkable. A dystonic reaction was diagnosed and diphenhydramine 50mg was administered intravenously, resulting in complete resolution of the episode within three minutes. No recurrence of dystonia occurred during four hours of observation. The patient was completely asymptomatic for one month following the episode, after which he was lost to follow-up.
