Synergistic effects between codeine and diclofenac after local, spinal and systemic administration
This study was designed to evaluate the extent of the antinociceptive interaction between codeine and diclofenac at the local, spinal and systemic level. The effects of individual and fixed-ratio combinations of locally, spinally or orally given codeine and diclofenac were assayed using the formalin...
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Published in | Pharmacology, biochemistry and behavior Vol. 76; no. 3; pp. 463 - 471 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
New York, NY
Elsevier Inc
01.12.2003
Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | This study was designed to evaluate the extent of the antinociceptive interaction between codeine and diclofenac at the local, spinal and systemic level. The effects of individual and fixed-ratio combinations of locally, spinally or orally given codeine and diclofenac were assayed using the formalin test in rats. Isobolographic analysis was employed to characterize the synergism produced by the combinations. Codeine, diclofenac and fixed-ratio codeine–diclofenac combinations produced a dose-dependent antinociceptive effect when administered locally, spinally or systemically. ED
30 values were estimated for the individual drugs and isobolograms were constructed. Theoretical ED
30 values for the combination estimated from the isobolograms were 422.2±50.5 μg/paw, 138.5±9.2 μg/rat, and 9.3±1.1 mg/kg for the local, spinal and oral routes, respectively. These values were significantly higher than the actually observed ED
30 values which were 211.1±13.6 μg/paw, 45.9±3.9 μg/rat, and 2.5±0.2 mg/kg, indicating a synergistic interaction. Systemic administration resulted in the highest increase in potency, being about fourfold, while spinal and local administration increased potency in two- and threefold, respectively. The fact that the highest synergism was observed after systemic administration suggests that the interaction is occurring at several anatomical sites. The results support the clinical use of this combination in pain management. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0091-3057 1873-5177 |
DOI: | 10.1016/j.pbb.2003.09.001 |