Correlação entre concentração liquórica e efeitos colaterais após injeção de morfina por via subaracnóidea em ratos
Correlation between CSF concentration and side effects after spinal morphine injection in rats
Neuzimar de Souza Freire Silva; Rioko Kimiko Sakata; Adriana Machado Issy
Resumo
Palavras-chave
Abstract
BACKGROUND AND OBJECTIVES: Spinal morphine promotes good pain relief, but is not free from side effects. This study aimed at verifying the correlation between CSF morphine concentration and side effects.
METHODS: This study involved 4 groups of 7 rats, which were studied 24 hours after spinal catheter insertion via cisterna magna. Groups G1, G2, G3 and G4 received respectively 0.1; 0.3; 0.5 and 1 µg morphine in 10 µl of 0.9% saline solution. CSF samples were collected and side effects were recorded at M15, M30, M60, M120 and M180 minutes after injection.
RESULTS: Side effects observed were: mandible tremors, agitation, pruritus, absence of diuresis, sedation, and respiratory changes. The incidence of side effects was higher during early evaluations and progressively decreased with time. Mean CSF morphine concentrations in G1 varied from 72.84 to 1.13 pg; in G2 from 114.26 to 5.68 pg; in G3 from 151.18 to 13.62 pg and in G4, from 561.37 to 18.61 pg.
CONCLUSIONS: There has been no correlation between CSF morphine concentration and side effects.
Keywords
Referências
Snyder SH, Pert CB, Pasternak GW. The opiate receptor. Ann Intern Med. 1974;81:534-540.
Hughes J, Smith T, Morgan B. Purification and properties of enkephalin: the possible endogenous ligand for the morphine receptor. Life Sci. 1975;16:1753-1758.
Yaksh L, Rudy TA. Chronic catheterization of the spinal subarachnoid space. Physiol Behav. 1976;17:1031-1036.
Van den Hoogen RHWM, Bervoets KJK, Colpaert TFC. Respiratory effects of epidural and subcutaneous morphine, meperidine, fentanyl and sufentanil in the rat. Anesth Analg. 1988;67:1071-1078.
Dib B. Intrathecal chronic catheterization in the rat. Pharmacol Biochem Behav. 1984;20:45-48.
Nishiyama T. A rat model of chronic lumbar epidural catheterization. Can J Anaesth. 1998;45:907-912.
Matos FF, Rollema H, Taiwo Y. Relationship between analgesia and extracelular morphine in brain and spinal cord in awake rats. Brain Research. 1995;693:187-195.
Bolander H, Kourtopoulos H, Lundberg S. Morphine concentrations in serum, brain and cerebrospinal fluid in the rat after intravenous administration of a single dose. J Pharm Pharmacol. 1983;35:656-659.