SUMMARY • 1Cholinergic agonists and acetylcholinesterase inhibitors, such as neostigmine, produce a muscarinic receptor-mediated antinociception in several animal species that depends on activation of spinal cholinergic neurons. However, neostigmine causes antinociception in sheep only in the early, and not late, postoperative period. • 2In the present study, a model of postoperative pain was used to determine the antinociceptive effects of bethanechol (a muscarinic agonist) and neostigmine administered intrathecally 2, 24 or 48 h after a plantar incision in a rat hind paw. Changes in the threshold to punctate mechanical stimuli were evaluated using an automated electronic von Frey apparatus. • 3Mechanical hyperalgesia was obtained following plantar incision, the effect being stronger during the immediate (2 h) than the late post-surgical period.

Bethanechol (15–90 µg/5 µL) or neostigmine (1–3 µg/5 µL) reduced incision-induced mechanical hyperalgesia, the effects of both drugs being more intense during the immediate (2 h) than the late post-surgical period. • 4The ED 50 for bethanechol injected at 2, 24 and 48 h was 5.6, 51.9 and 82.5 µg/5 µL, respectively.

The corresponding ED 50 for neostigmine was 1.62, 3.02 and 3.8 µg/5 µL, respectively. Roger Daltrey Anthology Rar on this page. • 5The decline in the antinociceptive potency of neostigmine with postoperative time is interpreted as resulting from a reduction in pain-induced activation of acetylcholine-releasing descending pathways. However, the similar behaviour of bethanechol in the same model points to an additional mechanism involving intrinsic changes in spinal muscarinic receptors.

Study Objective: To establish a dose-response curve for the analgesic effect of intrathecal neostigmine in patients undergoing below knee surgery with spinal anesthesia. To assess adverse effects, principally nausea and vomiting. Design: Randomized, double-blind, prospective study. Setting: Teaching hospital. Patients: 60 ASA physical status I and II premedicated patients undergoing orthopedic surgery (tibial or ankle reconstruction).

A study to compare intrathecal bupivacaine and bupivacaine with neostigmine for post operative analgesia in patients undergoing vaginal hysterectomy. Verisoft Access Manager Windows 7 64 Bit.

Interventions: Spinal anesthesia was performed at the sitting position, L 3-L 4 interspace, 4 ml final volume, injected at a rate of 1 ml/10 sec. The control group (CG) received 15 mg hyperbaric bupivacaine 0.5% plus saline. The 25 μg neostigmine group (25NG) received 15 mg hyperbaric bupivacaine plus 25 μg neostigmine; the 50 μg neostigmine group (50NG) received 15 mg hyperbaric bupivacaine plus 50 μg neostigmine; and the 100 μg neostigmine group (100NG) received 15 mg hyperbaric bupivacaine plus 100 μg neostigmine.

Patients were placed supine after the spinal punction. Measurements and Main Results: Time to first rescue analgesics, analgesia, and adverse effects at constant intervals were assessed using the 10 cm visual analog scale (VAS).

Intrathecal neostigmine produced a dose-independent reduction in the postoperative rescue analgesic consumption ( p 0.05), and the overall 24-hour VAS pain scores were lowest for patients who had spinal neostigmine ( p.