Publications (18) View all
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Article: Prolonged analgesic effect of amitriptyline base on thermal hyperalgesia in an animal model of neuropathic pain.
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ABSTRACT: The best analgesic drugs for neuropathic pain have a long duration of action, can be given via multiple routes, and can be used preemptively. We evaluated the antinociceptive effects and duration of action of subcutaneously injected amitriptyline base (AMT-Base) (in oil). A plantar test in a spinal nerve ligation (SNL) model of neuropathic pain in rats showed that typical amitriptyline HCl (AMT-HCl) (in saline) and AMT-Base had a significant dose-dependent antinociceptive effect: the antinociceptive duration of a single 100μmol/kg injection of AMT-HCl was 5h and of AMT-Base was 24h when given 7 days after a SNL, and of a single 200μmol/kg injection of AMT-Base was 39 days when given 1h before and 4 days when given 7 days after a SNL. The post-ligation antinociceptive duration of AMT-Base was 4.8 times that of AMT-HCl, but the duration of preemptive (pre-ligation) AMT-Base treatment was 9.7 times that of AMT-Base. We can conclude that preemptive amitriptyline base provides long-lasting antinociception for neuropathic pain experimentally.European journal of pharmacology 01/2013; · 2.59 Impact Factor -
Article: Cutaneous analgesia after subcutaneous injection of memantine and amantadine and their systemic toxicity in rats.
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ABSTRACT: The purpose of the study is to find subcutaneous equianalgesic doses of memantine, amantadine and bupivacaine and use these doses to quantify the cardiovascular and central nervous system toxicity of these agents after intravenous administration. Memantine, amantadine and bupivacaine, a local anesthetic, in a dose-related fashion were determined for cutaneous analgesia by a block of the cutaneous trunci muscle reflex in rats, and equipotent doses were calculated. Following rapid intravenous infusion of equianalgesic bupivacaine, memantine, amantadine and saline (vehicle) in rats, we observed the onset time of seizure, apnea and impending death, and monitored mean arterial blood pressure and heart rate. Memantine and amantadine elicited dose-dependent cutaneous analgesia. At the 50% effective dose (ED(50)), the rank of potencies was bupivacaine [1.8 (1.7-2.0)]>memantine [19.1 (17.6-21.8)]>amantadine [36.1 (32.0-40.3)] (P<0.05). On ED(25), ED(50) and ED(75) basis, the duration caused by bupivacaine was similar to that caused by memantine or amantadine. At equianalgesic doses, the infusion time of memantine or amantadine required to induce seizure, impending death, and apnea was longer than that of bupivacaine during rapid intravenous infusion (P<0.01). The decreasing slope in mean arterial blood pressure and heart rate was slower with memantine and amantadine when compared with bupivacaine at equivalent doses (P<0.01). Our data showed that memantine and amantadine (i) were equal to bupivacaine at producing durations of cutaneous analgesia but (ii) were less likely than bupivacaine to cause cardiovascular and central nervous system toxicity.European journal of pharmacology 08/2012; 693(1-3):25-30. · 2.59 Impact Factor -
Article: Low-dose dexamethasone effectively prevents postoperative nausea and vomiting after ambulatory laparoscopic surgery
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ABSTRACT: Purpose“To evaluate the prophylactic effect of low-dose dexamethasone (5 mg) on postoperative nausea and vomiting (PONV) in women undergoing ambulatory laparoscopic surgery. Metoclopramide and saline served as controls. MethodsOne hundred twenty women (n=40 in each of the three groups) undergoing ambulatory laparoscopic tubal ligation under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. After tracheal intubation, group I receivediv dexamethasone 5 mg, whereas groups II and III receivediv metoclopramide 10 mg and saline, respectively. ResultsPatients in group I reported a lower incidence of PONV and requested less rescue antiemetics than those in group III during the first four postoperative hours (P < 0.0l). Patients in group I reported a lower incidence of PONV than those in groups II (P < 0.05) and III (P < 0.0l) during the 24-hr postoperative period. Groups II and III did not differ from each other in the incidence of PONV and the proportion of patients who requested rescue antiemetics. ConclusionProphylacticiv dexamethasone 5 mg significantly reduces the incidence of PONV in women undergoing ambulatory laparoscopic tubal ligation. At this dose, dexamethasone is more effective than metoclopramide 10 mg or placebo. ObjectifÉvaluer l’effet prophylactique d’une faible dose de dexaméthasone (5 mg) sur les nausées et vomissements postopératoires (NVPO) chez des patientes de chirurgie laparoscopique ambulatoire. Le métoclopramide et une solution salée ont servi de témoins. MéthodeCent vingt femmes (n = 40 dans chacun des trois groupes formés de façon aléatoire), devant subir une ligature des trompes sous anesthésle générale en chirurgie laparoscopique ambulatoire, ont participé à l’étude randomisée, en double Insu et contrôlée contre placebo. Après l’intubation endotrachéale, les patientes du groupe I ont reçu 5 mg de dexaméthasone iv tandis que celles des groupes II et III ont reçu 10 mg de métoclopramide ou de solution salée iv, respectivement. RésultatsLes patientes du groupe I ont signalé une plus faible Incidence de NVPO et ont demandé moins d’antiémétiques de secours que les patientes du groupe III pendant les quatre premières heures postopératoires (P < 0,01). Les patients du groupe I ont eu moins de NVPO que celles des groupes II (P < 0,05) et III (P < 0,01) pendant une période de 24 h après l’intervention. Aucune différence intergroupe quant à l’incidence de NVPO et au nombre de patientes qui ont eu recours aux antiémétiques n’a été notée entre les patientes des groupes II et III. ConclusionL’administration iv de 5 mg de dexaméthasone réduit significativement l’incidence de NVPO chez des patientes qui subissent une ligature des trompes en chirurgie laparoscopique ambulatoire. Cést plus efficace que 10 mg de métoclopramide ou de placebo.Canadian Journal of Anaesthesia 04/2012; 48(10):973-977. · 2.35 Impact Factor -
Article: Nutrient deficiencies as a risk factor in Taiwanese patients with postherpetic neuralgia.
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ABSTRACT: Postherpetic neuralgia (PHN) is the most common complication of herpes zoster (HZ). The aim of the present study was to compare the nutritional status of PHN patients with that of healthy controls, and then to identify risk factors for PHN using multivariate multiple logistic regressions. In the present cross-sectional study, we prospectively enrolled fifty PHN patients for at least 3 months and fifty healthy controls. We selected nine circulating nutrients including ionised Ca, Zn, retinol, folic acid, vitamin B12, vitamin C, α-tocopherol, γ-tocopherol and lycopene associated with both immunity and the modulation of neuropathic pain, and measured their concentrations in plasma/serum. Concentrations of ionised Ca, Zn, vitamin C and vitamin B12 were significantly lower in PHN patients than in controls after excluding those patients receiving supplements since the outbreak of HZ. The prevalence of either mild/marginal or severe deficiencies for any of the nine selected circulating nutrients in PHN patients (92 %) was much higher than that in controls (46 %) (P < 0·001). Lower concentrations of vitamin C ( ≤ 45·0 μmol/l), ionised Ca ( ≤ 1·05 mmol/l) and Zn ( ≤ 0·91 g/l) were found to increase independently the risk of PHN using binary variable (dichotomy) analyses with both PHN patients and controls in a multivariate logistic regression analysis. No significant correlations existed between the risks of PHN and the concentrations of retinol, folic acid, vitamin B12, lycopene or α:γ-tocopherol ratios. Thus, lower concentrations of circulating nutrients, namely vitamin C, ionised Ca or Zn, are probably a risk factor in Taiwanese patients with PHN.The British journal of nutrition 04/2011; 106(5):700-7. · 3.45 Impact Factor -
Article: Tianeptine reduces morphine antinociceptive tolerance and physical dependence.
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ABSTRACT: Long-term use of morphine can cause neuronal dystrophic changes in specific areas of the brain. These changes may underlie the mechanism for developing morphine antinociceptive tolerance and physical dependence. We evaluated the effect of tianeptine, an antidepressant with prominent neuroprotective and neuroplastic properties, on the development of morphine antinociceptive tolerance and physical dependence. Male C57BL/6 mice were rendered tolerant to or dependent on morphine by subcutaneously injecting them with morphine (10 mg/kg) and intraperitoneally with saline or tianeptine (1, 3, or 5 mg/kg) twice daily for 6 days. The mice were given a daily tail-flick test 1 h after the first morphine injection to evaluate the development of their tolerance to morphine antinociception. To evaluate their physical dependence on morphine, 3 h after the final morphine injection on day 6, naloxone-HCl-precipitated (2 mg/kg, intraperitoneally) withdrawal symptoms were counted for 30 min, and body weight was checked 1 h after the naloxone injection. Tianeptine per se produced no antinociception, neither did it modify the antinociception produced by morphine, nor did it evoke the behavioral responses different from those in the saline controls. The combination of tianeptine with morphine significantly reduced the development of morphine antinociceptive tolerance and suppressed the incidence of naloxone-precipitated withdrawal symptoms. We conclude that tianeptine is an effective inhibitor of morphine-induced antinociceptive tolerance and physical dependence in mice. Our results would imply that comedication with tianeptine and morphine might benefit those who need long-term morphine treatment.Behavioural pharmacology 09/2010; 21(5-6):523-9. · 2.85 Impact Factor
