Doses Of Nefopam Research Articles

Effect of nefopam in normal chickens and its relationship to hydrogen peroxide-induced oxidative stress

The objective designated to discover the analgesic effect of nefopam in the normal (non-stressed) chickens and its possible alteration due to hydrogen peroxide (H2O2)-induced oxidative stress (OS) in 7-14 day old chickens. The analgesia of nefopam has been increased by 47% in the stressed chickens by measuring the analgesic Median Effective Dose (ED50) value. This value was 9.10 mg/kg, IM in the normal chickens where it became 4.80 mg/kg, IM in stressed chickens. There is a significant rise in the antinociceptive action of nefopam 18 mg/kg, IM by 88% in the stressed group of chickens in comparison with the normal one elicited by an electro-stimulation and formaldehyde 0.05 ml of 0.1% tests for induction of nociception. The observations showed several significant stimulatory modifications in the neurobehaviour when nefopam treated with a subtle dosage 1 mg/kg, IM in the stressed chickens concerning the latency to move, squares crossed and time of the tonic immobility response test. Significant damage was detected in the liver function when nefopam injected at 18 mg/kg, IM in stress chickens in comparison to normal one by 28, 33 and 65% as estimated through Alkaline phosphatase (ALP), Aspartate trans-aminase (AST) and Alanine trans-aminase (ALT) concentrations in the serum, respectively. The sum of data findings indicated that H2O2-inducedOS increased the analgesic activity of nefopam in the chickens; despite the changes occur on the neurobehaviour and liver function. The dose of nefopam should be reduced when preparing the therapeutic regimen in the stressed animals.

The Antiallodynic Effect of Nefopam on Vincristine-Induced Neuropathy in Mice.

BackgroundChemotherapy-induced neuropathic pain is a disabling condition following cancer treatment. Vincristine has more neurotoxicity than other vinca alkaloid agents. This study evaluated the correlation of different doses of nefopam with antiallodynic effects in a mouse vincristine neuropathy model.MethodsA peripheral neuropathic mouse model was made by intraperitoneal injection of vincristine (0.1 mg/kg/day; 5-day-on, 2-day-off schedule over 12 days). After the development of allodynia, mice were injected intraperitoneally with 0.9% normal saline (NS group) or various doses (10, 30, 60 mg/kg) of nefopam (Nefopam group). We examined allodynia using von Frey hairs pre-administration and at 30, 60, 90, 120, 180, 240 mins, and 24 hrs after drug administration. We also measured the neurokinin-1 receptor concentrations in the spinal cord to confirm the antiallodynic effect of nefopam after drug administration.ResultsThe peripheral neuropathic mouse model showed prominent mechanical allodynia. Intraperitoneal nefopam produced a clear dose-dependent increase in paw withdrawal threshold compared with pre-administration values and versus the NS group. The concentration of neurokinin-1 receptor was significantly decreased in the Nefopam group (P<0.05).ConclusionIntraperitoneally administered nefopam yielded a dose-dependent attenuation of mechanical allodynia and decreased neurokinin-1 receptor concentration, suggesting that the neurokinin-1 receptor is involved in the antiallodynic effects of nefopam in vincristine neuropathy.

The analgesic effect of nefopam with fentanyl at the end of laparoscopic cholecystectomy.

BackgroundNefopam is a centrally acting analgesic that is used to control pain. The aim of this study was to find an appropriate dose of nefopam that demonstrates an analgesic effect when administered in continuous infusion with fentanyl at the end of laparoscopic cholecystectomy.MethodsNinety patients scheduled for laparoscopic cholecystectomy were randomly assigned to receive analgesia with fentanyl alone (50 µg, Group 1, n = 30), or with fentanyl in combination with nefopam 20 mg (Group 2, n = 30) or in combination with nefopam 40 mg (Group 3, n = 30) at the end of surgery. Pain and side effects were evaluated at 10 minutes, 30 minutes, 1 hour, 2 hours, 6 hours, and 12 hours after arrival in the post-anesthesia care unit (PACU).ResultsPain was statistically significantly lower in Groups 2 and 3 than in Group 1 at 10 minutes, 2 hours, and 6 hours after arrival in the PACU. Nausea was statistically significantly lower in Group 2 than in Groups 1 and 3 at 10 minutes after arrival in the PACU. Shivering was statistically significantly lower in Groups 2 and 3 than in Group 1 at 10 minutes after arrival in the PACU.ConclusionsNefopam is a drug that can be safely used as an analgesic after surgery, and its side effects can be reduced when fentanyl 50 µg is injected with nefopam 20 mg.

The Effects of Nefopam on the Gain and Maximum Intensity of Shivering in Healthy Volunteers

Mild hypothermia has been shown to improve neurologic outcome after cardiac arrest. Nefopam, a centrally acting, nonsedative analgesic, decreases the threshold of shivering, but not vasoconstriction, and thus might be a suitable drug for induction of therapeutic hypothermia. However, not only the threshold but also the gain and maximum intensity of shivering define the thermoregulatory properties of a drug and thus are clinically important. Therefore, we evaluated the gain and maximum intensity of shivering at 2 different doses of nefopam and placebo. Seven healthy volunteers were randomly assigned to 3 study days: (1) control (saline), (2) small-dose nefopam (50 ng/mL), and (3) large-dose nefopam (100 ng/mL). On all study days volunteers were cooled using central venous infusion of cold IV fluid while mean skin temperature was maintained at 31 degrees C. Core temperature was recorded at the tympanic membrane. Threshold, gain, and maximum intensity of shivering were evaluated using oxygen consumption. Both 50 and 100 ng/mL nefopam significantly reduced the shivering threshold as well as the gain of shivering: shivering threshold: 35.6 degrees C + or - 0.2 degrees C (control); 35.2 degrees C + or - 0.3 degrees C (small dose); 34.9 degrees C + or - 0.5 degrees C (large dose), P = 0.004; gain of shivering: 597 + or - 235 mL x min(-1) x degrees C(-1) (control); 438 + or - 178 mL x min(-1) x degrees C(-1) (small dose); 301 + or - 134 mL x min(-1) x degrees C(-1) (large dose), P = 0.028. Maximum intensity of shivering did not differ among the 3 treatments. Nefopam significantly reduced the gain of shivering. This reduction, in combination with a reduced shivering threshold, will allow clinicians to cool patients even further when therapeutic hypothermia is indicated.

The Median Effective Dose of Nefopam and Morphine Administered Intravenously for Postoperative Pain After Minor Surgery

The Median Effective Dose of Nefopam and Morphine Administered Intravenously for Postoperative Pain After Minor Surgery

Evaluation of nefopam as a monoamine uptake inhibitor in vivo in mice

Nefopam antagonized 6-hydroxydopamine-induced depletion of heart norepinephrine in mice with an ED 50 value of 12 mg/kg. Nefopam was ineffective in antagonizing p-chloroamphetamine-induced depletion of brain serotonin in our standard assay in mice, apparently due to a short duration of action. Brain concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) were decreased after a 32 mg/kg, i.p., dose of nefopam at 1 and 2 hr but not at 4 hr. When nefopam was injected simultaneously with p-chloroamphetamine, it prevented brain serotonin depletion initially, but by 6 hr the protective effect was essentially lost, suggesting that p-chloroamphetamine persisted in mouse brain longer than did nefopam. Nefopam caused a dose-related antagonism of brain serotonin depletion at 2 hr after injection of a low dose of p-chloroamphetamine hydrochloride (10 mg/kg i.p.), with a calculated ED 50 value of 11 mg/kg. The lowering of brain 5-HIAA concentration 2 hr after nefopam injection occurred after a 32 mg/kg dose but not after a 3 or 10 mg/kg dose. These data suggest that nefopam is effective as an inhibitor of norepinephrine and serotonin uptake at doses previously shown to be analgesic in mice, consistent with uptake inhibition being a postulated mechanism important in its analgesic effect. Nonetheless, nefopam is a relatively weak inhibitor of monoamine uptake with a short duration of action in mice.