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J Spierdijk

Publications and source records attributed to J Spierdijk.

64 records · Page 4Linked to original sources
PubMedDate not supplied

Pharmacokinetics of lidocaine and bupivacaine and stable isotope labelled analogues: a study in healthy volunteers.

The pharmacokinetics of lidocaine and bupivacaine and tri-deuteromethyl-labelled lidocaine and bupivacaine were investigated in healthy volunteers. The deuterium-labelled and the unlabelled form of the drug to be investigated were simultaneously infused in 10 min. Plasma concentrations were determined using a combination of capillary gas chromatography and mass fragmentography. Bi-exponential functions were fitted to the plasma concentration-time data. The mean distribution and elimination half-lives were 8.4 +/- 5.9 min and 96 +/- 26 min for lidocaine, 9.2 +/- 7.0 min and 98 +/- 27 min for deuterium-labelled lidocaine, 15.3 +/- 9.9 min and 111 +/- 32 min for bupivacaine, and 15.2 +/- 10.9 min and 109 +/- 31 min for deuterium-labelled bupivacaine, respectively. The mean volumes of the central compartment and mean steady state volumes of distribution were: lidocaine 37 +/- 151 and 97 +/- 201, deuterium-labelled lidocaine 39 +/- 161 and 98 +/- 181, bupivacaine 27 +/- 111 and 66 +/- 231 and deuterium-labelled bupivacaine 28 +/- 121, and 65 +/- 221, respectively. The respective mean plasma clearances were 0.88 +/- 0.181 min-1, 0.87 +/- 0.181 min-1, 0.61 +/- 0.151 min-1, and 0.62 +/- 0.171 min-1. The results of the study indicate that substitution of a deuterated methyl group does not alter the pharmacokinetics of lidocaine and bupivacaine in healthy subjects.

Adult↗
PubMedDate not supplied

Threshold serum concentrations of bupivacaine associated with early CNS toxicity and pharmacokinetics of bupivacaine in young versus old rhesus monkeys.

Effects of aging on the onset of early signs of central nervous system (CNS) toxicity, associated total and free arterial threshold serum concentration, and the disposition of bupivacaine were studied in eight younger (11-15 years) and eight older (16-28 years) rhesus monkeys. Bupivacaine was infused at a rate of 0.15 mg/kg minute until unceasing movements of the eye, oscillating from side to side and up and down (nonpositional nystagmus). This was regarded as an objective sign of early CNS toxicity. Most animals showed drowsiness and sedation by the end of the infusion. CNS toxicity occurred significantly faster (p less than 0.025) in the younger (13.7 +/- 2.5 minutes) than in the older (17.1 +/- 2.6 minutes) animal group. A significant correlation was found between the onset time of CNS toxicity and age. The coefficient of determination (R2) for this correlation was 0.48. Also, the dose associated with the onset of CNS toxicity was significantly smaller in the younger (2.06 +/- 0.38 mg/kg) than in the older (2.60 +/- 0.39 mg/kg) animals. However, the total and free arterial threshold serum concentration of bupivacaine was similar in both groups. Age did not influence the disposition of bupivacaine.

Aging↗