Background. The factors affecting the concentrations of fentanyl in the brain after
intravenous administration have not been completely quantified. Methods. A model …

Pharmacokinetic (PK) and pharmacodynamic (PD) data were available from a study of a
nasal delivery system for the opioid analgesic fentanyl, together with data on the kinetics of …

Linear pharmacokinetic models were obtained for fentanyl in anaesthetized rabbits. A
composite model was used to predict the bolus dose and infusion rates necessary to …

We have studied the cerebral haemodynamic and metabolic effects of fentanyl 50 μg kg− 1
and 100 μg kg− 1 in dogs undergoing ventilation with oxygen and nitrogen at normocapnia …

Background. The analgesic effects of morphine are delayed relative to its concentration in
blood. The rate of equilibration of morphine between blood and brain may contribute to this …

Fentanyl reduces the cortical cerebral blood flow and metabolic rate for oxygen in rats,
though seizure activity occurs in some animals at high doses. However, the effects of …

Background Different opioids have different delays (hysteresis) between their concentrations
in blood and their cerebral effects. Possible mechanisms include differences in their rate of …

Background The influence of changes in the physiologic state of a patient on the disposition
of fentanyl and alfentanil is poorly understood. The aims of this study were to determine …

It is a clinical impression that less fentanyl is needed for anesthesia during hyperventilation
and hypocarbia. If true, it might be due to both increased penetration of fentanyl, a highly …

Traditionally, physiological pharmacokinetic models assume that arterial blood flow to tissue
is the rate-limiting step in the transfer of drug into tissue parenchyma. When this assumption …