Anesthesiology
Hesam Savadkoohi; Nasser Vesal
Volume 10, Issue 1 , March 2019, , Pages 31-36
Abstract
In order to assess possible synergistic antinociceptive interactions, the analgesic effects of intra-peritoneal tramadol and morphine administered either separately or in combination were determined using tail-flick latency test following exposure to radiant heat in rats. Groups of eight male Sprague-Dawley ...
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In order to assess possible synergistic antinociceptive interactions, the analgesic effects of intra-peritoneal tramadol and morphine administered either separately or in combination were determined using tail-flick latency test following exposure to radiant heat in rats. Groups of eight male Sprague-Dawley rats received either tramadol (3.90, 7.00, 12.50, and 22.20 mg kg-1) and morphine (1.26, 2.25, 4.00 and 7.10 mg kg-1) or a combination of tramadol and morphine (4 different combinations). The baseline latency was obtained before drug injection for each rat, then at 15, 30, 45, 60 and 75 min after injection. The effective dose (ED)50 for either tramadol or morphine individually was 11.70 mgkg-1 and 2.26 mg kg-1, respectively. Based on isobolographic analysis, the ED50 values obtained by drug combination were significantly less than the calculated additive values; which indicates that the co-administration of tramadol and morphine produces synergistic antinociception in the radiant heat tail-flick assay. Combination of morphine and tramadol administered intra-peritoneally can be used for the control of acute pain in rats.
Physiology
Mehrzad Foroud; Nasser Vesal
Volume 6, Issue 4 , December 2015, , Pages 313-318
Abstract
The purpose of the present study was to evaluate anti-nociceptive effects of morphine, tramadol, meloxicam and their combinations in rats. Seventy male Wistar rats were divided into seven equal groups and randomly assigned to receive intraperitoneal saline (S) (control group, 1.0 mL kg-1), morphine (MO) ...
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The purpose of the present study was to evaluate anti-nociceptive effects of morphine, tramadol, meloxicam and their combinations in rats. Seventy male Wistar rats were divided into seven equal groups and randomly assigned to receive intraperitoneal saline (S) (control group, 1.0 mL kg-1), morphine (MO) (4.0 mg kg-1), tramadol (TR) (12.5 mg kg-1), meloxicam (ML) (1.0 mg kg-1), tramadol- morphine (TR-MO), meloxicam-morphine (ML-MO) and meloxicam-tramadol (ML-TR) at the same doses. Anti-nociception was evaluated using tail flick latency (TFL) test at 45, 60, 75, 90 and 120 min after drug injection. The TFL was significantly higher in TR and MO groups compared to S group for 90 and 120 min, respectively. No significant change in TFL from baseline values was observed at all time points in ML group. Among rats that received combination of analgesics, those that received TR-MO had significantly greater TFL. There was no significant difference in TFL between ML-TR and ML-MO groups. In conclusion, TR, MO and their combination all provided acceptable anti-nociceptive effects in rats. Meloxicam at the given dosage (1.0 mg kg-1) did not demonstrate any anti-nociceptive effect when evaluated by TFL test.
Safoura Ghadirian; Nasser Vesal
Volume 4, Issue 3 , September 2013, , Pages 161-167
Abstract
This blinded, randomized experimental study was designed to evaluate the analgesic effects of adding epinephrine or xylazine to lidocaine solution for brachial plexus block (BPB) in sheep. Nine healthy, fat-tailed female lambs (26.6 ± 1.5 kg) were randomly allocated into three groups: lidocaine ...
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This blinded, randomized experimental study was designed to evaluate the analgesic effects of adding epinephrine or xylazine to lidocaine solution for brachial plexus block (BPB) in sheep. Nine healthy, fat-tailed female lambs (26.6 ± 1.5 kg) were randomly allocated into three groups: lidocaine 2%, 5 mg kg-1 (LID, n = 6), lidocaine (5 mg kg-1) with epinephrine 5 µg mL-1 (LIDEP, n = 6) or lidocaine (5 mg kg-1) with xylazine 0.05 mg kg-1 (LIDXY, n = 6). Each animal was tested twice. The sheep received a total volume of 0.25 mL kg-1 for BPB. A nerve stimulator was used to locate the nerves of the brachial plexus. Onset and duration of analgesia of the forelimb were evaluated using superficial and deep pin prick and pinching of skin with a hemostat clamp. Heart and respiratory rates, and rectal temperature were recorded before and at predetermined intervals following the completion of the block. Brachial administration of LID, LIDEP or LIDXY produced forelimb analgesia within 11.3, 11.0 and 7.0 minutes, respectively. The mean duration of analgesia was 100.0 min in LID and 133.2 min in LIDEP group. The mean duration of analgesia in LIDXY group (186.8 min) was significantly longer compared with LID group. In LIDEP group a significant increase in heart rate occurred 5 min after drug administration. Heart rate decreased from 35 to 80 minin sheep received LIDXY. In conclusion, the addition of xylazine to lidocaine solution for BBP provided a prolonged duration of action without any adverse effects in fat-tailed sheep.
