Abstract
Intra-articular morphine (5 mg in 25 ml) was administered to patients for post-operative analgesia following arthroscopic knee surgery. At various time intervals, 30 min to 4 h post morphine, venous blood samples were taken in order to determine plasma levels of morphine and its primary metabolites, morphine-3-glucuronide and morphine-6-glucuronide. Measurable amounts of morphine and morphine-3-glucuronide were found in the plasma of 7/10 patients whereas morphine-6-glucuronide was detected in only 2/10 patients. The plasma levels of morphine were lower than that regarded sufficient for post-operative analgesia in all but two patients, indicating a possibility of peripheral analgesia. [p]In addition, synovial biopsy samples were assayed for the presence of opioid binding sites. Tissue samples from 11 different patients were analysed and 6/11 exhibited specific binding of [3H]naloxone, indicating the presence of opioid binding sites/receptors. The receptor type (i. e. μ, δ- or k-) is at present unknown. [p]Taken together, these data provide evidence that locally administered opiates can act on specific opioid receptors in the synovium to mediate analgesia.
Original language | English (US) |
---|---|
Pages (from-to) | 351-355 |
Number of pages | 5 |
Journal | European Journal of Clinical Pharmacology |
Volume | 43 |
Issue number | 4 |
DOIs | |
State | Published - Oct 1 1992 |
Keywords
- Analgesia
- Opioids
- inflammation
- peripheral
- receptors
ASJC Scopus subject areas
- Pharmacology
- Pharmacology (medical)