Cerebrospinal fluid levels of d-tubocurarine in man

Using radioimmunoassay, d-tubocurarine (dTc) was found in the cerebrospinal fluid (CSF) of man after intravenous injection. When dTc was administered in a single dose (0.3 mg/kg) to nine patients, small quantities, 3.5 +/- .26 ng/ml (mean +/- SE), appeared in the lumbar CSF within 5 minutes. The concentration of dTc (0.3 mg/kg) were given at 90 minute intervals. Concentration of dTc in the CSF remained constant for the next 25 minutes, but then began to increase with time to to 9.3 +/- 4.4 ng/ml 30 minutes after injection, 14.5 +/- 4.4 ng/ml at one hour, and 24.9 +/- 6.5 ng/ml at six hours. In another group of six patients, three doses of dTc (0.3 mg/kg) were given at 90-minute intervals. Concentration of dTc in the CSF increased after each injection. The quantities of dTc found in the CSF are unlikely to produce any pharmacologic or adverse effect (e.g., convulsion) in man.