School of Medical Sciences

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https://hdl.handle.net/2440/295
The School of Medical Sciences encompasses the disciplines of Anatomical Sciences, Pathology and Pharmacology.

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Browsing School of Medical Sciences by Author "Abadi, R."

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    Flexible dosing of Tincture of Opium in the management of opioid withdrawal: pharmacokinetics and pharmacodynamics
    (Blackwell Publishing Ltd, 2008) Somogyi, A.; Larsen, M.; Abadi, R.; Jittiwutikarn, J.; Ali, R.; White, J.

    Aims

    The aim was to evaluate the clinical effectiveness, pharmacodynamics and pharmacokinetics of a range of Tincture of Opium (TOP) doses in the management of opioid withdrawal.

    Methods

    Forty-five opium-dependent Thai subjects were allocated to three dosing groups (6.66, 13.3 and 20 mg morphine equivalents, twice daily) depending on their self-reported prior opium use. On day 5 of dosing subjects underwent an interdosing interval study where blood, withdrawal scores, heart rate and blood pressure (BP) were collected at 0, 1, 3 and 8 h. Plasma morphine concentrations were quantified by high-performance liquid chromatography, and plasma morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) concentrations by LCMS.

    Results

    Thirty-two subjects completed the study. Withdrawal scores were low for all subjects (range 9-23% of maximum response). There were dose-dependent changes in both systolic and diastolic BP (P = 0.021 and P = 0.01, respectively), but these were not considered clinically significant. There were no effects of dose on respiratory rate. Plasma morphine concentrations changed significantly across the interdosing interval (P = 0.0001), rising to a maximum at 1 h after dosing. Plasma morphine concentrations also differed according to dose (P < 0.05). The mean ratios of the morphine glucuronides were found to be: M3G/M6G = 7.7, M3G/morphine = 35.6 and M6G/morphine = 4.9, values comparable to those previously reported.

    Conclusion

    The management of opioid withdrawal can be achieved, with minimal adverse effects, by using flexible dosing of TOP.