Neuromodulation : journal of the International Neuromodulation Society
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We determined whether intrathecally delivering the same daily dose of morphine (MS) at a fixed concentration of 25 mg/mL by periodic boluses versus continuous infusion would reduce intrathecal mass (IMs) formation in dogs. ⋯ Using multiple bolus dosing, IMs were reduced as compared to continuous infusion, suggesting relevance of bolus delivery in yielding reduced intrathecal masses.
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Conversion between routes such as intravenous (IV), epidural (EP), and intrathecal (IT) routes for morphine is well established. Conversion ratios for IV:EP:IT fentanyl and conversion from IT morphine/hydromorphone to IT fentanyl have been challenging given the lipophilic nature of fentanyl. Our study reviews the outcomes and conversion ratios reached after converting IT opioids from morphine/hydromorphone to fentanyl in patients with IT pumps. ⋯ Given the pharmacokinetics of lipophilic fentanyl compared to hydrophilic morphine/hydromorphone, the current conversion ratio of IV fentanyl to IT fentanyl and IV morphine to IT fentanyl appears to be conservative.
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DMT-DALDA (H-Dmt-D-Arg-Phe-Lys-NH2; Dmt = 2',6'-dimethyltyrosine) is a selective mu opioid agonist. We sought to characterize efficacy, tolerance, dependence and side-effect profile when given by continuous intrathecal infusion. ⋯ These data suggest that DMT-DALDA is a potent, spinally active agonist with a propensity to produce tolerance dependence and mast cell degranulation. While it was equiactive to morphine in producing mast cell degranulation, it was >1000 fold more potent in producing analgesia, suggesting a possible lower risk in producing a spinal mass at equianalgesic doses.