Abstract | BACKGROUND AND OBJECTIVE: METHODS: Pharmacokinetic sample data (175 patients on RP5063; 28 doses/patient) were analyzed, utilized one- and two-compartment models, and evaluated the impact of covariates. Pharmacodynamic analysis involved development of an Emax model. RESULTS: The pharmacokinetic analysis identified a one-compartment model incorporating body mass index influence on volume as the optimum construct, with fixed-effect parameters: (1) oral clearance (Cl/F), 5.11 ± 0.11 L/h; (2) volume of distribution (Vc/F), 328.00 ± 31.40 L; (3) absorption constant (ka) 0.42 ± 0.17 h-1; (4) lag time (t lag) of 0.41 ± 0.02 h; and (5) a calculated half-life of 44.5 h. Pharmacokinetics were linear related to dose. An Emax model for total Positive and Negative Syndrome Scale (PANSS) scores as the response factor against cumulative area under the curve (AUC) provided fixed-effect estimates: (1) Eo = 87.3 ± 0.71 (PANSS Units; pu); (2) Emax = - 31.60 ± 4.05 (pu); and (3) AUC50 = 89.60 ± 30.10 (µg·h/mL). The predicted PANSS improvement reflected a clinical dose range of 5-30 mg. CONCLUSIONS: Pharmacokinetics of RP5063 behaved predictably and consistently. Pharmacodynamics were characterized using an Emax model, reflecting total PANSS score as a function of cumulative AUC, that showed high predictability and low variability when correlated with actual observations.
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Authors | Marc Cantillon, Robert Ings, Arul Prakash, Laxminarayan Bhat |
Journal | European journal of drug metabolism and pharmacokinetics
(Eur J Drug Metab Pharmacokinet)
Vol. 43
Issue 5
Pg. 573-585
(Oct 2018)
ISSN: 2107-0180 [Electronic] France |
PMID | 29619682
(Publication Type: Clinical Trial, Phase II, Journal Article, Multicenter Study, Randomized Controlled Trial)
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Chemical References |
- Antipsychotic Agents
- Organic Chemicals
- RP5063
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Topics |
- Administration, Oral
- Adolescent
- Adult
- Aged
- Antipsychotic Agents
(administration & dosage, blood, pharmacokinetics)
- Double-Blind Method
- Drug Administration Schedule
- Female
- Humans
- Male
- Middle Aged
- Models, Biological
- Organic Chemicals
(administration & dosage, blood, pharmacokinetics)
- Psychotic Disorders
(blood, diagnosis, drug therapy)
- Schizophrenia
(blood, diagnosis, drug therapy)
- Young Adult
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