Browsing by Author "Boakye, Maxwell"

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    ItemOpen Access
    A prospective, multicenter, phase I matched-comparison group trial of safety, pharmacokinetics, and preliminary efficacy of riluzole in patients with traumatic spinal cord injury.
    (Journal of neurotrauma, 2014-02) Grossman, Robert G; Fehlings, Michael G; Frankowski, Ralph F; Burau, Keith D; Chow, Diana SL; Tator, Charles; Teng, Angela; Toups, Elizabeth G; Harrop, James S; Aarabi, Bizhan; Shaffrey, Christopher I; Johnson, Michele M; Harkema, Susan J; Boakye, Maxwell; Guest, James D; Wilson, Jefferson R
    A prospective, multicenter phase I trial was undertaken by the North American Clinical Trials Network (NACTN) to investigate the pharmacokinetics and safety of, as well as obtain pilot data on, the effects of riluzole on neurological outcome in acute spinal cord injury (SCI). Thirty-six patients, with ASIA impairment grades A-C (28 cervical and 8 thoracic) were enrolled at 6 NACTN sites between April 2010 and June 2011. Patients received 50 mg of riluzole PO/NG twice-daily, within 12 h of SCI, for 14 days. Peak and trough plasma concentrations were quantified on days 3 and 14. Peak plasma concentration (Cmax) and systemic exposure to riluzole varied significantly between patients. On the same dose basis, Cmax did not reach levels comparable to those in patients with amyotrophic lateral sclerosis. Riluzole plasma levels were significantly higher on day 3 than on day 14, resulting from a lower clearance and a smaller volume of distribution on day 3. Rates of medical complications, adverse events, and progression of neurological status were evaluated by comparison with matched patients in the NACTN SCI Registry. Medical complications in riluzole-treated patients occurred with incidences similar to those in patients in the comparison group. Mild-to-moderate increase in liver enzyme and bilirubin levels were found in 14-70% of patients for different enzymes. Three patients had borderline severe elevations of enzymes. No patient had elevated bilirubin on day 14 of administration of riluzole. There were no serious adverse events related to riluzole and no deaths. The mean motor score of 24 cervical injury riluzole-treated patients gained 31.2 points from admission to 90 days, compared to 15.7 points for 26 registry patients, a 15.5-point difference (p=0.021). Patients with cervical injuries treated with riluzole had more-robust conversions of impairment grades to higher grades than the comparison group.
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    ItemOpen Access
    Impact of US hospital center and interhospital transfer on spinal cord injury management: An analysis of the National Trauma Data Bank.
    (The journal of trauma and acute care surgery, 2021-06) Williamson, Theresa; Hodges, Sarah; Yang, Lexie Zidanyue; Lee, Hui-Jie; Gabr, Mostafa; Ugiliweneza, Beatrice; Boakye, Maxwell; Shaffrey, Christopher I; Goodwin, C Rory; Karikari, Isaac O; Lad, Shivanand; Abd-El-Barr, Muhammad

    Background

    Traumatic spinal cord injury (SCI) is a serious public health problem. Outcomes are determined by severity of immediate injury, mitigation of secondary downstream effects, and rehabilitation. This study aimed to understand how the center type a patient presents to and whether they are transferred influence management and outcome.

    Methods

    The National Trauma Data Bank was used to identify patients with SCI. The primary objective was to determine association between center type, transfer, and surgical intervention. A secondary objective was to determine association between center type, transfer, and surgical timing. Multivariable logistic regression models were fit on surgical intervention and timing of the surgery as binary variables, adjusting for relevant clinical and demographic variables.

    Results

    There were 11,744 incidents of SCI identified. A total of 2,883 patients were transferred to a Level I center and 4,766 presented directly to a level I center. Level I center refers to level I trauma center. Those who were admitted directly to level I centers had a higher odd of receiving a surgery (odds ratio, 1.703; 95% confidence interval, 1.47-1.97; p < 0.001), but there was no significant difference in terms of timing of surgery. Patients transferred into a level I center were also more likely to undergo surgery than those at a level II/III/IV center, although this was not significant (odds ratio, 1.213; 95% confidence interval, 0.099-1.48; p = 0.059).

    Conclusion

    Patients with traumatic SCI admitted to level I trauma centers were more likely to have surgery, particularly if they were directly admitted to a level I center. This study provides insights into a large US sample and sheds light on opportunities for improving pre hospital care pathways for patients with traumatic SCI, to provide the timely and appropriate care and achieve the best possible outcomes.

    Level of evidence

    Care management, Level IV.
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    ItemOpen Access
    Longitudinal Impact of Acute Spinal Cord Injury on Clinical Pharmacokinetics of Riluzole, a Potential Neuroprotective Agent.
    (Journal of clinical pharmacology, 2021-09) Nguyen, Ashley; Chow, Diana S-L; Wu, Lei; Teng, Yang Angela; Sarkar, Mahua; Toups, Elizabeth G; Harrop, James S; Schmitt, Karl M; Johnson, Michele M; Guest, James D; Aarabi, Bizhan; Shaffrey, Christopher I; Boakye, Maxwell; Frankowski, Ralph F; Fehlings, Michael G; Grossman, Robert G
    Riluzole, a benzothiazole sodium channel blocker that received US Food and Drug Administration approval to attenuate neurodegeneration in amyotrophic lateral sclerosis in 1995, was found to be safe and potentially efficacious in a spinal cord injury (SCI) population, as evident in a phase I clinical trial. The acute and progressive nature of traumatic SCI and the complexity of secondary injury processes can alter the pharmacokinetics of therapeutics. A 1-compartment with first-order elimination population pharmacokinetic model for riluzole incorporating time-dependent clearance and volume of distribution was developed from combined data of the phase 1 and the ongoing phase 2/3 trials. This change in therapeutic exposure may lead to a biased estimate of the exposure-response relationship when evaluating therapeutic effects. With the developed model, a rational, optimal dosing scheme can be designed with time-dependent modification that preserves the required therapeutic exposure of riluzole.
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    ItemOpen Access
    Pharmacology of riluzole in acute spinal cord injury.
    (Journal of neurosurgery. Spine, 2012-09) Chow, Diana SL; Teng, Yang; Toups, Elizabeth G; Aarabi, Bizhan; Harrop, James S; Shaffrey, Christopher I; Johnson, Michele M; Boakye, Maxwell; Frankowski, Ralph F; Fehlings, Michael G; Grossman, Robert G

    Object

    The aim of this paper was to characterize individual and population pharmacokinetics of enterally administered riluzole in a Phase 1 clinical trial of riluzole as a neuroprotective agent in adults 18-70 years old with acute spinal cord injury (SCI).

    Methods

    Thirty-five individuals with acute SCI, American Spinal Injury Association Impairment Scale Grades A-C, neurological levels from C-4 to T-12, who were enrolled in the Phase 1 clinical trial sponsored by the North American Clinical Trials Network for Treatment of Spinal Cord Injury, received 50 mg riluzole twice daily for 28 doses. The first dose was administered at a mean of 8.7 ± 2.2 hours postinjury. Trough plasma samples were collected within 1 hour predose, and peak plasma samples were collected 2 hours postdose on Days 3 and 14 of treatment. Riluzole concentrations were quantified by high-performance liquid chromatography assay. The data were analyzed for individual and population pharmacokinetics using basic structural and covariate models. The pharmacokinetic measures studied were the peak concentration (C(max)), trough concentration (C(min)), systemic exposure (AUC(0-12)), clearance (CL/F), and volume of distribution (V_F) normalized by the bioavailability (F).

    Results

    The C(max) and AUC(0-12) achieved in SCI patients were lower than those in ALS patients on the same dose basis, due to a higher CL and larger V. The pharmacokinetics of riluzole (C(max), C(min), AUC(0-12), CL, and V) changed during the acute and subacute phases of SCI during the 14 days of therapy. It was consistently observed in patients at all clinical sites that C(max), C(min), and AUC(0-12) (128.9 ng/ml, 45.6 ng/ml, and 982.0 ng × hr/ml, respectively) were significantly higher on Day 3 than on Day 14 (76.5 ng/ml, 19.1 ng/ml, and 521.0 ng × hr/ml, respectively). These changes resulted from lower CL (49.5 vs 106.2 L/hour) and smaller V (557.1 vs 1297.9/L) on Day 3. No fluid imbalance or cytochrome P 1A2 induction due to concomitant medications was identified during the treatment course to account for such increases in V and CL, respectively. Possible mechanisms underlying these changes are discussed.

    Conclusions

    This is the first report of clinical pharmacokinetics of riluzole in patients with SCI. The C(max) and AUC(0-12) achieved in SCI patients were lower than those in ALS patients on the same dose basis, due to a higher clearance and larger volume of distribution in SCI patients. The finding in SCI patients of an increase in the clearance and distribution of riluzole between the 3rd and 14th days after SCI, with a lower plasma concentration of riluzole on the 14th day, stresses the importance of monitoring changes in drug metabolism after SCI in interpreting the safety and efficacy of therapeutic drugs that are used in clinical trials in SCI. Clinical trial registration no.: NCT00876889.