RESUMO
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the best therapeutic options to treat pain. Their use in combination with other drugs may broaden their applicability in analgesia if their ceiling and adverse effects are reduced. The aim of this study was to evaluate the pharmacological interaction of two NSAIDs, paracetamol and meloxicam, with the antipsychotic drug risperidone in mice, in several experimental tests of nociceptive and inflammatory pain. Antinociception was assessed by dose-response curves to paracetamol and meloxicam before and after the i.p. administration of 0.5 mg/kg of risperidone. Results are presented as means ± SEM and differences were calculated by one-way ANOVA followed by Tukey's post-test. Paracetamol and meloxicam produced a dose-related antinociceptive effect with diverse potencies. Risperidone increased the analgesia mediated by paracetamol and meloxicam only in the tonic tests that detected inflammatory pain. This suggests that COX inhibition is only a partial explanation of the increased analgesic potency of paracetamol and meloxicam since the effects of NSAIDs in the CNS are mediated by multiple mechanisms. These results indicate that the combination of risperidone with paracetamol or meloxicam could be a new and effective alternative for the management of inflammatory pain.
Assuntos
Acetaminofen , Analgesia , Acetaminofen/farmacologia , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Meloxicam/farmacologia , Meloxicam/uso terapêutico , Camundongos , Dor/tratamento farmacológico , Risperidona/farmacologia , Risperidona/uso terapêuticoRESUMO
Pain models are mostly in rodents and between them formalin orofacial test allow discrimination among antinociception and anti-inflammation. This assay use a formalin solution injected into the upper right lip of each mouse which produces two periods of pain separated by an inactive period. The aims of the present study were to evaluate, by means of the isobolographic analysis, the antinociception and anti-inflammatory activities of the following NSAIDs: dexketoprofen, diclofenac, piroxicam and metamizole in an orofacial. The NSAIDs administered intraperitoneally produced a dose-dependent activity with the following order of potency of the rubbing behavior, in phase I: diclofenac>dexketoprofen>piroxicam>metamizole and in the phase II: metamizole>diclofenac>piroxicam>dexketoprofen. The coadministration of NSAIDs resulted in a synergistic interaction, which according to the value of the potency of the combination (II) presents the following range: dexketoprofen plus metamizole>dexketoprofen plus diclofenac>dexketoprofen plus piroxicam, in phase I and dexketoprofen plus metamizole>dexketoprofen plus piroxicam>dexketoprofen plus diclofenac, on the phase II. Data obtained in this work corroborate that NSAIDs alone or in combination inducing activities by additional mechanism of action supplementary to inhibition of COXs. This fact represent a novel approach that could be used as multimodal management of orofacial pain, since with this treatment strategies, by the reduction of doses, can help to diminish side effects of other dugs such opioids.
Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Dor/tratamento farmacológico , Animais , Modelos Animais de Doenças , Sinergismo Farmacológico , Masculino , CamundongosRESUMO
There are different animal models to evaluate pain among them the formalin hind paw assay which is widely used since some of its events appear to be similar to the clinical pain of humans. The assay in which a dilute solution of formalin is injected into the dorsal hindpaw of a murine produces two 'phases' of pain behavior separated by a inactive period. The early phase (Phase I) is probably due to direct activation of nociceptors and the second phase (Phase II) is due to ongoing inflammatory input and central sensitization. Mice were used to determine the potency antinociceptive of piroxicam (1,3,10,and 30 mg/kg), parecoxib (0.3, 1,3,10 and 30 mg/kg), dexketoprofen (3,10,30 and 100 mg/kg) and ketoprofen (3,10,30 and 100 mg/kg). Dose-response for each NSAIDs were created before and after 5 mg/kg of L-NAME i.p. or 5 mg/kg i.p. of 7-nitroindazole. A least-squares linear regression analysis of the log dose-response curves allowed the calculation of the dose that produced 50% of antinociception (ED50) for each drug. The ED50 demonstrated the following rank order of potency, in the phase I: piroxicam > dexketoprofen > ketoprofen > parecoxib and in the phase II: piroxicam > ketoprofen > parecoxib > dexketoprofen. Pretreatment of the mice with L-NAME or 7-nitroindazol induced a significant increase of the analgesic power of the NSAIDs, with a significant reduction of the ED50. It is suggested that NO may be involved in both phases of the trial, which means that nitric oxide regulates the bioactivity of NSAIDs.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Óxido Nítrico/metabolismo , Nociceptividade/efeitos dos fármacos , Dor/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Modelos Animais de Doenças , Formaldeído/toxicidade , Humanos , Indazóis/administração & dosagem , Masculino , Camundongos , NG-Nitroarginina Metil Éster/administração & dosagem , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Nociceptores/efeitos dos fármacos , Nociceptores/metabolismo , Dor/induzido quimicamente , Dor/diagnóstico , Medição da DorRESUMO
Different NSAIDs are used as antinociceptive in various analgesic assays, among which should be mentioned: ibuprofen, ketorolac , ketoprofen, meloxicam , paracetamol and others. It has been shown that NSAIDs possess antinociceptive activity by blocking cyclooxygenase enzymes (COXs). The present study was designed to evaluate the possible involvement of the nitridergic pathway due to L-NAME and the opioidergic route by NTX in the antinoception induced by NSAIDs using a murine pain model the tail flick test in an automatic tail flick algesiometer. The antinociception was evaluated by means of isobolographic analysis. The interaction between the combination of NSAIDs, via i.p., on basis of their ED25, demonstrated that the coadministration of the drugs were synergistic with the exception of the lack of effect in combination of meloxicam with ibuprofen and with ketorolac, since the result was additive. These data validate that the NSAIDs administered alone or in combinations produce antinociception in which other mechanisms of action must be added to the simple inhibition of COXs. In addition, the pretreatment of the mice with L-NAME and NTX does not change previous isobolographic parameters of the mixture of NSAIDs.
Assuntos
Analgésicos Opioides/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Óxido Nítrico/metabolismo , Acetaminofen/farmacologia , Animais , Inibidores de Ciclo-Oxigenase/farmacologia , Ibuprofeno/farmacologia , Cetoprofeno/farmacologia , Cetorolaco/farmacologia , Camundongos , Dor/tratamento farmacológico , Dor/metabolismo , Medição da Dor/métodosRESUMO
The principal mechanism of action of non-steroidal anti-inflammatory drugs (NSAIDs) is the inhibition of ciclooxigenases. In this study was evaluated if NSAIDs could induce antinociceptive differences according to the type of murine pain model. Male mice were injected intraperitoneally with meloxicam, diclofenac, piroxicam, metamizol, ibuprofen, naproxen and paracetamol in the writhing, tail flick and formalin orofacial tests and dose-response were analyzed to obtain the ED50 of each drugs. Administration of NSAIDs produced in a dose-dependent antinociception with different potency in the tests. The relative potency of NSAIDs among the tests shows a value of 5.53 in the orofacial formalin test in phase I and 6.34 in phase II between meloxicam and paracetamol; of 7.60 in the writhing test between meloxicam and paracetamol and of 8.46 in the tail flick test between ibuprofen and paracetamol. If the comparison is made for each NSAID in the different tests, the minimum value was 0.01 for between writhing and phase II of the orofacial formalin. Meanwhile, the highest power ratio was 11.71 for diclofenac between writhing and tail flick tests. In conclusion, the results suggests that intraperitoneal NSAIDs administration induce antinociceptive activity depending on the type of pain. The results support that NSAIDs administration, induce a wide variety of antinociceptive effect, depending on the type of pain. This suggest the participation of different mechanisms of action that can be added to the simple inhibition of COXs controlled by NSAIDs.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Nociceptividade/efeitos dos fármacos , Dor/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Injeções Intraperitoneais , Masculino , Camundongos , Dor/etiologia , Dor/patologia , Medição da Dor , Prostaglandina-Endoperóxido Sintases/metabolismoRESUMO
BACKGROUND: Quillaja saponaria Mol. bark contains a high concentration of triterpene saponins that have been used for centuries as a cleansing, antiinflammatory and analgesic agent in Chilean folk medicine. In earlier studies, in mice, both the anti-inflammatory as well as the antinociceptive effect of the major sapogenin, quillaic acid have been demonstrated (QA). OBJECTIVE: To determine the antihyperalgesic effect of QA one and seven days after itpl administration of complete Freund's adjuvant (CFA) in male mice using the hot plate test in the presence of complete Freund's adjuvant (HP/CFA) as an acute and chronic skeletal muscle pain model. METHODS: The present study evaluated the antihyperalgesic activity of QA against acute and chronic skeletal muscle pain models in mice using the hot plate test in the presence of complete Freund's adjuvant (HP/CFA), at 24 h (acute assay) and 7 days (chronic assay) , with dexketoprofen (DEX) as the reference drug. RESULTS: In acute and chronic skeletal muscle pain assays, QA at 30 mg/kg ip elicited its maximal antihyperalgesic effects (65.0% and 53.4%) at 24 h and 7 days, respectively. The maximal effect of DEX (99.0 and 94.1 at 24 h and 7 days, respectively) was induced at 100 mg/kg. CONCLUSION: QA and DEX elicit dose-dependent antihyperalgesic effects against acute and chronic skeletal muscle pain, but QA is more potent than DEX in the early and late periods of inflammatory pain induced by CFA.
Assuntos
Músculos Abdominais/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Ácido Oleanólico/análogos & derivados , Dor/tratamento farmacológico , Quillaja/química , Animais , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos , Conformação Molecular , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologiaRESUMO
Nonsteroidal anti-inflammatory drugs (NSAIDs) possess as primary action mechanism the inhibition of cyclooxygenases (COX-1, COX-2, and COX-3), thus producing a decreasing prostaglandin synthesis. This study was designed to evaluate whether the antinociception induced by NSAIDs could be modulated by clomipramine or risperidone using a chemical model of inflammatory acute visceral pain, the abdominal acetic acid induced a writhing test in mice. Dose-response curves, intraperitoneal, or intrathecal for the antinociceptive activity displayed by ketoprofen, piroxicam, nimesulide, parecoxib, and paracetamol were analyzed in order to obtain the ED50 of each drug. Pretreatment of mice with either clomipramine or risperidone, increased antinociceptive potency of ketoprofen, piroxicam, nimesulide, parecoxib, and paracetamol, expressed by a decrease in the values of antinociceptive ED50. The results that were obtained are in line with those where the inhibition of COXs provides a justification for most of the pharmacological actions. Nevertheless, several findings suggest other molecular mechanisms, among which may be mentioned, L-selecting shedding; inhibition of i-NOS; inhibition of NF-Kappa B; suppression metaloproteinasas; inhibition of ß2 integrin activation; activation of α2 -adrenoceptor; increase of IL-1ß; upregulation IL-6. In conclusion, the data generated in this study demonstrated that risperidone and clomipramine, separately, increase antinociceptive potency of NSAIDs in a chemical model of inflammatory acute visceral tonic pain.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Clomipramina/uso terapêutico , Risperidona/uso terapêutico , Dor Visceral/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Clomipramina/administração & dosagem , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Injeções Intraperitoneais , Injeções Espinhais , Masculino , Camundongos Endogâmicos , Medição da Dor , Risperidona/administração & dosagemRESUMO
Neuropathic pain is the result of injury to the nervous system, and different animal models have been established to meet the manifestations of neuropathy. The pharmacotherapy for neuropathic pain includes gabapentin and tramadol, but these are only partially effective when given alone. The aim of this study was to assess the antinociceptive interaction between both drugs using the isobolographic analysis and changes of the IL-1ß concentration in a mouse model of neuropathic pain (partial sciatic nerve ligation or PSNL). The i.p. administration of gabapentin (5-100 mg/kg) or tramadol (12.5-100 mg/kg) displayed a dose-dependent antinociception in the hot plate assay of PSNL mice, and effects induced by gabapentin with tramadol were synergistic. Administration of gabapentin or tramadol reversed significantly the increase in the concentration of IL-1ß induced by PSNL after either 7 or 14 days and their combination was significantly more potent in reversing the elevated concentration of IL-1ß. The synergism obtained by the co-administration of gabapentin and tramadol is proposed to result from action on different mechanisms in pain pathways. Gabapentin or tramadol or their combination modulates the expression of pro-inflammatory cytokine, IL-1ß, in a model of mice PSNL which could be due to an inhibition of glial function.
Assuntos
Aminas/farmacologia , Analgésicos/farmacologia , Ácidos Cicloexanocarboxílicos/farmacologia , Mononeuropatias/tratamento farmacológico , Neuralgia/tratamento farmacológico , Tramadol/farmacologia , Ácido gama-Aminobutírico/farmacologia , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Gabapentina , Interleucina-1beta/metabolismo , Modelos Lineares , Masculino , CamundongosRESUMO
BACKGROUND AND METHODS: Neuropathic pain results from nerve injury, and gabapentin, an antiepileptic drug, has been approved for the treatment of several types of neuropathic pain. On the other hand, nortriptyline, an antidepressant drug, has been suggested as an alternative treatment. In partial sciatic nerve ligation (PSNL) mice, the interaction of gabapentin with nortriptyline was evaluated by the hot plate assay using isobolographic analysis. RESULTS: Gabapentin (3-100 mg/kg, i.p.) or nortriptyline (1-30 mg/kg, i.p.) induced dose-dependent antinociception, with an ED50 of 11.60 ± 0.54 mg/kg for gabapentin and of 5.16 ± 0.21 mg/kg for nortriptyline. The potency of gabapentin and nortriptyline in PSNL mice at 7 and 14 days after ligation was significantly increased (p < 0.05). Coadministration of gabapentin with nortriptyline, at a 1:1 ratio of their ED50, had a synergistic effect, with an interaction index of 0.311 and 0.348 for these mice at 7 and 14 days, respectively. CONCLUSION: The data showed a synergy in antinociception at a gabapentin-to-nortriptyline ratio of 1:1 in PSNL mice. This finding suggests that this combination could provide a therapeutic alternative that can be used for neuropathic pain management.
Assuntos
Aminas/uso terapêutico , Analgésicos/uso terapêutico , Ácidos Cicloexanocarboxílicos/uso terapêutico , Neuralgia/tratamento farmacológico , Nortriptilina/uso terapêutico , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Nervo Isquiático/lesões , Ácido gama-Aminobutírico/uso terapêutico , Animais , Sinergismo Farmacológico , Quimioterapia Combinada , Gabapentina , Temperatura Alta , Masculino , CamundongosRESUMO
Neosaxitoxin (NeoSTX) is a specific reversible blocker of voltage gated sodium channels on excitable cells. In the last decade, it has been tested in a number of interesting clinical trials, however there is still little information available on mammalian toxicity. Rats were treated for 12 weeks with doses of 1, 3 or 6 µg/kg of subcutaneous NeoSTX. At weeks 12 and 17, animals were sacrificed and blood samples collected for hematological and biochemical analysis. Organs were harvested for weight determination and histopathological assessments. The lowest acute toxicity via the intraperitoneal (ip) route was (30.35 µg/kg) and there was no significant difference between intramuscular and subcutaneous routes (11.4 and 12.41 µg/kg). The NeoSTX adiministration did not produce lethality at week 12 and after five weeks of suspension. NeoSTX 6 µg/kg ip produced reductions (p < 0.05) in body weight and food intake, and increased blood level of total and direct bilirubin, GGT and SGOT at week 12; all of these were reversed in the recovery period. NeoSTX 1 and 3 µg/kg ip did not show significant changes with the control group. Histopathological presentations were normal in all groups. This study revealed that NeoSTX is safe in vivo, giving a reliable security margin for its use like a local anesthetic.