Preliminary evaluation of epidural morphine for treatment of heroin withdrawal.

Objective: To evaluate the efficacy of epidural morphine in treating heroin withdrawal in patients who failed to detoxify by the other methods.

Design: Prospective study.

Setting: Department of Psychiatry of a general hospital.

Perineural antinociceptive effect of opioids in a rat model.

Background: The research on conductive analgesia induced by perineural opioids generated a large body of conflicting data. In this study we reassessed the antinociceptive response to perineural administration of morphine, fentanyl or meperidine in a rat model.

Methods: Analgesia was assessed using the hind paw withdrawal latency (HPWL) response to radiant heat.

Quantifiable dose-dependent withdrawal after morphine discontinuation in a rat model.

We evaluated the intensity of the withdrawal symptoms after the discontinuation of the morphine infusion in rats. Opiate addiction was induced by progressively increasing intraperitoneal morphine infusion rates. The control group (Group 1) received normal saline.

A method of reducing the opioid withdrawal intensity using progressively increasing doses of naloxone.

We assessed the withdrawal intensity in acutely morphine-dependent mice using a pretreatment with escalating doses of naloxone. All animals received a single dose of morphine (100 mg/kg) for the induction of acute opioid dependency. Group 1 (control) received three injections of normal saline and then naloxone 0.

Preliminary evaluation of Vipera palaestinae snake bite treatment in accordance to the severity of the clinical syndrome.

The intravenous administration of a 60 ml dose of Vipera palaestinae antivenin was the suggested standard treatment of every bitten patient. In this study 85 Vipera palaestinae bitten patients where selectively treated with antivenin depending on the severity of the clinical picture. Patients who developed systemic or severe local signs received 20 ml of antivenin over 30 min.

Intrathecal administration of liposomal morphine in a mouse model.

The authors determined the duration of analgesia, toxicity, and neuraxial distribution of liposomal morphine after intrathecal administration in the mouse. Analgesic duration was determined using the tail-flick test after intrathecal injection of 12.5, 25, or 50 micrograms of plain or liposomal morphine (n = 6 mice/dose/formulation).

Hot plate versus tail flick: evaluation of acute tolerance to continuous morphine infusion in the rat model.

The development of tolerance to continuous morphine infusion (2, 4 and 6 mg x kg(-1) x hr(-1) was assessed in rats using two different methods for evaluation of nociception, tail flick (TF) and hot plate (HP). The influence of repeated testing on nociception was evaluated using two regimens; series 1 was tested repeatedly 1, 2, 4, 6, and 8 hr after initiating the morphine infusion and series 2 was tested only twice, at maximum morphine effect and at 8 hr. Both, TF and HP showed pain threshold elevation after the morphine administration of 4 or 6 mg x kg(-1) x hr(-1), which reached a maximum at 2 hr after the start of the infusion.

Prolonged analgesia and decreased toxicity with liposomal morphine in a mouse model.

Inadequate control of postoperative pain remains a major clinical problem. A reliable method of providing long-lasting postoperative analgesia with a single dose would be very useful. We synthesized a liposomal morphine formulation and compared it to free morphine with regard to duration of analgesia in the mouse.

The partition coefficient as a predictor of local anesthetic potency for spinal anesthesia: evaluation of five local anesthetics in a mouse model.

Local anesthetic partition coefficients correlate with drug potencies in vitro, but in vivo data have not always complimented in vitro results. Despite extensive studies on intrathecal anesthetic action, whether there is correlation between the partition coefficient and local anesthetic potency has not been addressed. Mice (n = 150) were randomly allocated into 15 groups.

Prolonged analgesia with liposomal bupivacaine in a mouse model.

Background And Objectives: Currently available local anesthetics have relatively limited duration of action and some may cause severe systemic toxicity. An ultralong lasting local anesthetic would be useful to produce prolonged intraoperative anesthesia and extended postoperative analgesia. The goal of this study was to synthesize a sustained release local anesthetic formulation that would produce prolonged sensory block and decrease the possibility of systemic toxicity.

Duration of spinal anaesthesia is determined by the partition coefficient of local anaesthetic.

We have compared the duration of motor block produced by four local anaesthetics administered into a chronically implanted subarachnoid catheter in rabbits. Each group (n = 6) received four different doses of amethocaine, bupivacaine, lignocaine or procaine, and the duration of the resulting motor block was assessed. Dose-response curves were plotted for each drug.

Discrepancy between the development of tolerance to bupivacaine in extradural and spinal anaesthesia in rabbits.

We gave equal groups of rabbits seven extradural (500 micrograms kg-1) or intrathecal (250 micrograms kg-1) injections of bupivacaine, at 24-h intervals. A decrease in the duration of motor block was observed after the extradural injections. The intrathecal injections exerted a reproducible effect.

Assessing local anesthetic effect using the mouse tail flick test.

We used the tail flick test to quantify duration of local anesthetic-induced conduction block in the mouse. Using a baseline tail flick latency (TFL) between 1.0 and 2.

Prolongation of epidural anesthesia using a lipid drug carrier with procaine, lidocaine, and tetracaine.

This study evaluated the effect of a lipid drug carrier (iophendylate) on epidural anesthesia. The intensity and duration of motor blockade produced by aqueous and lipid preparations of local anesthetics were assessed in rabbits with long-term indwelling catheters in the epidural space. Motor blockades produced by procaine (1%, 2%, and 4%), lidocaine (1%, 2%, and 4%), and tetracaine (0.

A rat sciatic nerve model for independent assessment of sensory and motor block induced by local anesthetics.

The purpose of this study was to develop a reliable model to independently quantify motor and sensory block produced by local anesthetics. The sciatic nerve was blocked in 52 rats by injecting 0.2 mL of 0.

Prolongation of spinal anesthesia. Differential action of a lipid drug carrier on tetracaine, lidocaine, and procaine.

This study evaluates prolongation of spinal anesthesia by incorporating local anesthetics in lipid formulation. The duration and intensity of local anesthetic effect produced by different concentrations of procaine (1%, 2%, 4%), lidocaine (1%, 2%, 4%), or tetracaine (0.5%, 1%, 2%) dissolved in normal saline were compared to those produced by the same concentration of drugs in lipid (iophendylate) solution.

Prolongation of the pharmacologic effect of intrathecal meperidine by the use of a lipid solution of it.

The possibility of prolonging the effect of intrathecally injected meperidine by the use of a lipid solution was examined in this study. An aqueous solution of 5% meperidine HCl, 250 micrograms/kg, and an equimolar solution of meperidine dissolved in iophendylate (Pantopaque) were injected subarachnoidally in two groups of rabbits (n = 9 in each) with chronically implanted catheters in the subarachnoid space at the level of L7-8. The effect of each injection was assessed by evaluation of the pain threshold in the animal's hind limbs and of the degree of motor blockade produced.

Spinal anesthesia: significant prolongation of the pharmacologic effect of tetracaine with lipid solution of the agent.

A novel approach for increasing the duration of anesthesia after a single subarachnoid injection of a local anesthetic is presented. Tetracaine 1% 0.5 mg/kg was administered in 10% glucose or in lipid solution (iophendylate) in two groups of rabbits via catheters chronically implanted in the subarachnoid space.

A rabbit model for evaluation of spinal anesthesia: chronic cannulation of the subarachnoid space.

A rabbit model for evaluation of spinal anesthesia is presented. Chronic cannulation of the subarachnoid space was performed in 44 rabbits using the translumbar approach. An autopsy was performed 24 h after the operation on four of the animals.

Side-effect evaluation of a new diazepam formulation: venous sequela reduction following intravenous (i.v.) injection of a diazepam emulsion in rabbits.

Diazepam has been incorporated into a stable, submicronized injectable emulsion. Venous sequela induction in rabbits following iv administration of diazepam in a marketed hydroalcoholic solution and in the emulsion were determined and compared over a 5-day period. There was a marked difference in the local reactions induced by the iv administration of the marketed diazepam hydroalcoholic solution and the diazepam emulsion, even on the first postinjection day.