Assessment of the Effects of Abrocitinib on the Pharmacokinetics of Probe Substrates of Cytochrome P450 1A2, 2B6 and 2C19 Enzymes and Hormonal Oral Contraceptives in Healthy Individuals.

BACKGROUND AND OBJECTIVE: Abrocitinib is an oral small-molecule Janus kinase (JAK)-1 inhibitor approved for the treatment of moderate-to-severe atopic dermatitis. In vitro studies indicated that abrocitinib is a weak time-dependent inhibitor of cytochrome P450 (CYP) 2C19/3A and a weak inducer of CYP1A2/2B6/2C19/3A. To assess the potential effect of abrocitinib on concomitant medications, drug-drug interaction (DDI) studies were conducted for abrocitinib with sensitive probe substrates of these CYP enzymes. The impact of abrocitinib on hormonal oral contraceptives (ethinyl estradiol and levonorgestrel), as substrates of CYP3A and important concomitant medications for female patients, was also evaluated. METHODS: Three Phase 1 DDI studies were performed to assess the impact of abrocitinib 200 mg once daily (QD) on the probe substrates of: (1) 1A2 (caffeine), 2B6 (efavirenz) and 2C19 (omeprazole) in a cocktail study; (2) 3A (midazolam); and (3) 3A (oral contraceptives). RESULTS: After multiple doses of abrocitinib 200 mg QD, there is a lack of effect on the pharmacokinetics of midazolam, efavirenz and contraceptives. Abrocitinib increased the area under the concentration time curve from 0 to infinity (AUCinf) and the maximum concentration (Cmax) of omeprazole by approximately 189 and 134%, respectively. Abrocitinib increased the AUCinf of caffeine by 40% with lack of effect on Cmax. CONCLUSIONS: Based on the study results, abrocitinib is a moderate inhibitor of CYP2C19. Caution should be exercised when using abrocitinib concomitantly with narrow therapeutic index medicines that are primarily metabolized by CYP2C19 enzyme. Abrocitinib is a mild inhibitor of CYP1A2; however, the impact is not clinically relevant, and no general dose adjustment is recommended for CYP1A2 substrates. Abrocitinib does not inhibit CYP3A or induce CYP1A2/2B6/2C19/3A and does not affect the pharmacokinetics of contraceptives. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov registration IDs: NCT03647670, NCT05067439, NCT03662516.

Population Pharmacokinetic and Pharmacodynamic Modeling of Fesoterodine in Pediatric Patients with Neurogenic Detrusor Overactivity.

BACKGROUND AND OBJECTIVE: Fesoterodine is a muscarinic receptor antagonist approved for the treatment of overactive bladder (OAB) in adults and neurogenic detrusor overactivity (NDO) in pediatric patients. This work aimed to characterize the population pharmacokinetics of 5-hydroxymethyl tolterodine (5-HMT, the active metabolite of fesoterodine) and its pharmacokinetic/pharmacodynamic relationship in pediatric patients with OAB or NDO following administration of fesoterodine. METHODS: 5-HMT plasma concentrations from 142 participants of age ≥ 6 years were analyzed, and a nonlinear mixed-effects model was developed. Weight-based simulations of 5-HMT exposure and maximum cystometric capacity (MCC) were conducted using the final models. RESULTS: A one-compartment model with first-order absorption and a lag time, which included the effects of body weight, sex, cytochrome (CYP) 2D6 metabolizer status and fesoterodine formulation on pharmacokinetic parameters, best described the 5-HMT pharmacokinetics. An Emax model described the exposure-response relationship adequately. The median maximum concentration at steady state for pediatric patients weighing 25-35 kg and receiving 8 mg once daily (QD) was estimated to be 2.45 times greater than that in adults receiving 8 mg QD. Furthermore, simulation results showed dosing with fesoterodine 4 mg QD to pediatric patients weighing 25-35 kg and 8 mg QD to pediatric patients weighing >35 kg would achieve adequate exposure to demonstrate a clinically meaningful change from baseline (CFB) MCC. CONCLUSIONS: Population models were developed for 5-HMT and MCC in pediatric patients. Weight-based simulations indicated that 4 mg QD for pediatric patients weighing 25-35 kg and 8 mg QD for those weighing > 35 kg provided similar exposures to those in adults following 8 mg QD and a clinically meaningful CFB MCC. CLINICAL TRIAL NUMBERS: NCT00857896, NCT01557244.

Fesoterodine is a muscarinic receptor antagonist approved for the treatment of overactive bladder (OAB) in adults and neurogenic detrusor overactivity (NDO) in pediatric patients in the US. Population pharmacokinetic and pharmacokinetic/pharmacodynamic models were developed for 5-HMT based on data from two pediatric clinical trials that included 142 patients of age ≥ 6 years with OAB or NDO. Weight-based simulations of 5-HMT exposure and maximum cystometric capacity were conducted using the final models to examine the impact of covariates on 5-HMT exposure and the exposure­response profile. The results of these simulations indicate that 4 mg QD for pediatric patients weighing 25­35 kg and 8 mg QD for those weighing > 35 kg provide similar exposures to those in adults following 8 mg QD.

The Pharmacokinetics, Metabolism, and Clearance Mechanisms of Abrocitinib, a Selective Janus Kinase Inhibitor, in Humans.

Abrocitinib is an oral once-daily Janus kinase 1 selective inhibitor being developed for the treatment of moderate-to-severe atopic dermatitis. This study examined the disposition of abrocitinib in male participants following oral and intravenous administration using accelerator mass spectroscopy methodology to estimate pharmacokinetic parameters and characterize metabolite (M) profiles. The results indicated abrocitinib had a systemic clearance of 64.2 L/h, a steady-state volume of distribution of 100 L, extent of absorption >90%, time to maximum plasma concentration of ∼0.5 hours, and absolute oral bioavailability of 60%. The half-life of both abrocitinib and total radioactivity was similar, with no indication of metabolite accumulation. Abrocitinib was the main circulating drug species in plasma (∼26%), with 3 major monohydroxylated metabolites (M1, M2, and M4) at >10%. Oxidative metabolism was the primary route of elimination for abrocitinib, with the greatest disposition of radioactivity shown in the urine (∼85%). In vitro phenotyping indicated abrocitinib cytochrome P450 fraction of metabolism assignments of 0.53 for CYP2C19, 0.30 for CYP2C9, 0.11 for CYP3A4, and ∼0.06 for CYP2B6. The principal systemic metabolites M1, M2, and M4 were primarily cleared renally. Abrocitinib, M1, and M2 showed pharmacology with similar Janus kinase 1 selectivity, whereas M4 was inactive. SIGNIFICANCE STATEMENT: This study provides a detailed understanding of the disposition and metabolism of abrocitinib, a Janus kinase inhibitor for atopic dermatitis, in humans, as well as characterization of clearance pathways and pharmacokinetics of abrocitinib and its metabolites.

Population Pharmacokinetic/Pharmacodynamic Modeling of the Effect of Abrocitinib on QT Intervals in Healthy Volunteers.

Abrocitinib is a selective Janus kinase 1 inhibitor for the treatment of moderate to severe atopic dermatitis (AD). To assess the relationship between abrocitinib plasma concentrations and heart rate (HR)-corrected QT (QTc) and HR and calculate the effect of abrocitinib on these parameters at supratherapeutic concentrations, 36 healthy volunteers received single doses of abrocitinib 600 mg, placebo, and moxifloxacin 400 mg in a 3-period crossover study. The relationship between change from baseline in Fridericia-corrected QTc (∆QTcF) values and abrocitinib plasma concentrations was modeled using a prespecified linear mixed-effects model. The 90%CIs for time-matched placebo-corrected ∆QTcF (∆∆QTcF) were calculated from model parameter estimates and assessed against the regulatory threshold (10 millisecond) at the predicted supratherapeutic concentration in patients with atopic dermatitis (2156 ng/mL). Mean (90%CI) time-matched placebo-corrected change from baseline in HR (∆∆HR) was calculated similarly. At the supratherapeutic concentration, mean (90%CI) estimates for ∆∆QTcF and ∆∆HR were 6.00 (4.52-7.49) milliseconds and 6.51 (5.23-7.80) bpm, respectively. Despite a concentration-dependent effect on ∆QTcF and ∆HR, with statistically significant slopes (90%CI) of 0.0026 (0.0018-0.0035) milliseconds/(ng/mL) and 0.0031 (0.0024-0.0038) bpm/(ng/mL), respectively, abrocitinib does not have a clinically significant effect on QTc interval or HR at supratherapeutic exposures.

Population pharmacokinetic-pharmacodynamic modelling of platelet time-courses following administration of abrocitinib.

AIMS: Abrocitinib is a selective Janus kinase 1 inhibitor for the treatment of moderate-to-severe atopic dermatitis. Herein we describe the time-course of drug-induced platelet reduction following abrocitinib administration, identify covariates affecting platelet counts, and determine the probability of patients experiencing thrombocytopaenia while receiving abrocitinib. METHODS: This analysis included data from two Phase 2 and three Phase 3 studies in psoriasis and atopic dermatitis patient populations administered abrocitinib 10-400 mg QD orally for up to 12 weeks, with platelet counts determined up to week 16. A semi-mechanistic model was developed to assess the impact of baseline platelet counts (170, 220 and 270 × 1000/µL), age and race on the platelet nadir and week 12 counts with once-daily abrocitinib 200 mg or 100 mg. RESULTS: Decreases in platelet counts were transient with the nadir occurring on average 24 days (95% prediction interval, 23-24) after continuous administration of abrocitinib 200 mg QD. Following administration of once-daily abrocitinib 200 mg, the probabilities of thrombocytopaenia (<150 × 1000/µL) at the nadir were 8.6% and 95.5% for the typical patient with baseline platelet count of 270 × 1000/µL or 170 × 1000/µL, respectively. Adolescents had a lower probability of thrombocytopaenia compared with adults; platelet count distribution was similar in Asian and Western patients at the nadir and at week 12. CONCLUSION: This analysis supports the safety of once-daily abrocitinib 200 mg and 100 mg dosing regimens, with low probability of thrombocytopaenia during treatment, except for higher risk of low-grade thrombocytopaenia that diminished after 4 weeks in patients with low baseline platelet counts.

Assessment of the Effects of Inhibition or Induction of CYP2C19 and CYP2C9 Enzymes, or Inhibition of OAT3, on the Pharmacokinetics of Abrocitinib and Its Metabolites in Healthy Individuals.

BACKGROUND AND OBJECTIVE: Abrocitinib is a Janus kinase 1-selective inhibitor for the treatment of moderate-to-severe atopic dermatitis. Abrocitinib is eliminated primarily by metabolism involving cytochrome P450 (CYP) enzymes. Abrocitinib pharmacologic activity is attributable to the unbound concentrations of the parent molecule and 2 active metabolites, which are substrates of organic anion transporter 3 (OAT3). The sum of potency-adjusted unbound exposures of abrocitinib and its 2 active metabolites is termed the abrocitinib active moiety. We evaluated effects of CYP inhibition, CYP induction, and OAT3 inhibition on the pharmacokinetics of abrocitinib, its metabolites, and active moiety. METHODS: Three fixed-sequence, open-label, phase I studies in healthy adult volunteers examined the drug-drug interactions (DDIs) of oral abrocitinib with fluvoxamine and fluconazole, rifampin, and probenecid. RESULTS: Co-administration of abrocitinib with fluvoxamine or fluconazole increased the area under the plasma concentration-time curve from time 0 to infinity (AUCinf) of the unbound active moiety of abrocitinib by 91% and 155%, respectively. Co-administration with rifampin decreased the unbound active moiety AUCinf by 56%. The OAT3 inhibitor probenecid increased the AUCinf of the unbound active moiety by 66%. CONCLUSIONS: It is important to consider the effects of DDIs on the abrocitinib active moiety when making dosing recommendations. Co-administration of strong CYP2C19/2C9 inhibitors or CYP inducers impacted exposure to the abrocitinib active moiety. A dose reduction by half is recommended if abrocitinib is co-administered with strong CYP2C19 inhibitors, whereas co-administration with strong CYP2C19/2C9 inducers is not recommended. No dose adjustment is required when abrocitinib is administered with OAT3 inhibitors. CLINICAL TRIALS REGISTRATION IDS: NCT03634345, NCT03637790, NCT03937258.

Population Pharmacokinetics of Abrocitinib in Healthy Individuals and Patients with Psoriasis or Atopic Dermatitis.

BACKGROUND AND OBJECTIVE: Abrocitinib is a Janus kinase 1 inhibitor in development for the treatment of atopic dermatitis (AD). This work characterized orally administered abrocitinib population pharmacokinetics in healthy individuals, patients with psoriasis, and patients with AD and the effects of covariates on abrocitinib exposure. METHODS: Abrocitinib concentration measurements (n = 6206) from 995 individuals from 11 clinical trials (seven phase I, two phase II, and two phase III) were analyzed, and a non-linear mixed-effects model was developed. Simulations of abrocitinib dose proportionality and steady-state accumulation of maximal plasma drug concentration (Cmax) and area under the curve (AUC) were conducted using the final model. RESULTS: A two-compartment model with parallel zero- and first-order absorption, time-dependent bioavailability, and time- and dose-dependent clearance best described abrocitinib pharmacokinetics. Abrocitinib coadministration with rifampin resulted in lower exposure, whereas Asian/other race coadministration with fluconazole and fluvoxamine, inflammatory skin conditions (psoriasis/AD), and hepatic impairment resulted in higher exposure. After differences in body weight are accounted for, Asian participants demonstrated a 1.43- and 1.48-fold increase in Cmax and AUC, respectively. The overall distribution of exposures (Cmax and AUC) was similar in adolescents and adults after accounting for differences in total body weight. CONCLUSIONS: A population pharmacokinetics model was developed for abrocitinib that can be used to predict abrocitinib steady-state exposure in the presence of drug-drug interaction effects or intrinsic patient factors. Key covariates in the study population accounting for variability in abrocitinib exposures are Asian race and adolescent age, although these factors are not clinically meaningful. CLINICAL TRIAL NUMBERS: NCT01835197, NCT02163161, NCT02201524, NCT02780167, NCT03349060, NCT03575871, NCT03634345, NCT03637790, NCT03626415, NCT03386279, NCT03937258.

Abrocitinib is a drug approved in the UK and Japan for the treatment of atopic dermatitis. A population pharmacokinetic model for abrocitinib was developed based on data from 11 clinical trials that included 995 healthy individuals or patients with atopic dermatitis or psoriasis. Simulations of different patient factors, such as age, race, sex, body weight, liver function, and drug­drug interactions, were tested to examine differences in abrocitinib drug levels achieved in the body. The results of these simulations indicate that although there are some differences in abrocitinib exposure, no dose adjustments of abrocitinib are necessary based on these factors.

Effects of Renal Impairment on the Pharmacokinetics of Abrocitinib and Its Metabolites.

Abrocitinib, an oral once-daily Janus kinase 1 selective inhibitor, is under development for the treatment of atopic dermatitis. This phase 1, nonrandomized, open-label, single-dose study (NCT03660241) investigated the effect of renal impairment on the pharmacokinetics, safety, and tolerability of abrocitinib and its metabolites following a 200-mg oral dose. Twenty-three subjects with varying degrees of renal function (normal, moderate, and severe impairment) were enrolled. Active moiety exposures were calculated as the sum of unbound exposures for abrocitinib and its active metabolites. For abrocitinib, the adjusted geometric mean ratios (GMRs; %) for area under the concentration-time curve from time 0 extrapolated to infinite time and maximum plasma concentration were 182.91 (90% confidence interval [CI], 117.09-285.71) and 138.49 (90% CI, 93.74-204.61), respectively, for subjects with moderate renal impairment vs normal renal function; corresponding GMRs were 121.32 (90% CI, 68.32-215.41) and 99.11 (90% CI, 57.30-171.43) for subjects with severe impairment vs normal renal function. Metabolite exposures generally increased in subjects with renal impairment. The GMRs of unbound area under the concentration-time curve from time 0 extrapolated to infinite time and maximum plasma concentration of active moiety were 210.20 (90% CI, 154.60-285.80) and 133.87 (90% CI, 102.45-174.92), respectively, for subjects with moderate renal impairment vs normal renal function. Corresponding values were 290.68 (90% CI, 217.39-388.69) and 129.49 (90% CI, 92.86-180.57) for subjects with severe renal impairment vs normal renal function. Abrocitinib was generally safe and well tolerated. Both moderate and severe renal impairment led to higher exposure to abrocitinib active moiety, suggesting that abrocitinib dose should be reduced by half for patients with moderate or severe renal impairment. ClinicalTrials.gov identifier: NCT03660241.

Effects of Hepatic Impairment on the Pharmacokinetics of Abrocitinib and Its Metabolites.

Abrocitinib, an oral once-daily Janus kinase 1 selective inhibitor, is under development for treatment of atopic dermatitis. This phase 1, nonrandomized, open-label, single-dose study (NCT03626415) investigated the effect of hepatic impairment on pharmacokinetics (PK), safety, and tolerability of abrocitinib and its metabolites after a 200-mg oral dose. Twenty-four subjects with varying degrees of hepatic function (normal, mild, and moderate impairment) were enrolled (N = 8/group). Active moiety PK parameters were calculated as the sum of unbound PK parameters for abrocitinib and its active metabolites. For abrocitinib, the ratios (percentages) of adjusted geometric means for area under the concentration-time curve from time 0 extrapolated to infinite time (AUCinf ) and maximum plasma concentration (Cmax ) were 133.33 (90% confidence interval [CI], 86.17-206.28) and 94.40 (90%CI, 62.96-141.55), respectively, for subjects with mild hepatic impairment vs normal hepatic function. The corresponding comparisons of ratios (percentages) for AUCinf and Cmax were 153.99 (90%CI, 99.52-238.25) and 105.53 (90%CI, 70.38-158.24), respectively, for subjects with moderate hepatic impairment. Exposures of the metabolites were generally lower in subjects with hepatic impairment. For abrocitinib active moiety, the ratios (percentages) of adjusted geometric means of unbound AUCinf were 95.74 (90%CI, 72.71-126.08) and 114.82 (90%CI, 87.19-151.20) in subjects with mild and moderate impairment vs normal hepatic function, respectively. Abrocitinib was generally safe and well tolerated. Hepatic impairment had no clinically relevant effect on the PK and safety of abrocitinib and the exposure of abrocitinib active moiety. These results support the use of abrocitinib without dose adjustment in subjects with mild or moderate hepatic impairment.

Effects of intravenous oxycodone alone or in combination with naltrexone on measures of respiratory depression: a randomized placebo-controlled study.

BACKGROUND: Abuse of prescription opioids, particularly by intravenous (IV) administration, can cause respiratory depression and death. ALO-02, an abuse-deterrent opioid formulation, is designed to release sequestered naltrexone upon manipulation by crushing, thereby antagonizing the pharmacologic effects of oxycodone. This exploratory post-hoc analysis examined the effects of IV administration of simulated crushed ALO-02 on end-tidal carbon dioxide (EtCO2), a surrogate marker of respiratory depression. METHODS: Data were obtained from a randomized, double-blind, placebo-controlled, three-way crossover study in nondependent recreational opioid users that evaluated the abuse potential of IV administered oxycodone 20 mg + naltrexone 2.4 mg (simulating crushed ALO-02) versus oxycodone 20 mg or placebo. EtCO2 was measured as a secondary endpoint using noninvasive capnography at baseline and postdose intervals, up to 24 h. RESULTS: Baseline EtCO2 (mean ± standard error of the mean (SEM)) values (n = 33) were similar across treatments: 33.5 ± 0.9, 33.5 ± 0.8, and 34.0 ± 0.7 mmHg for oxycodone 20 mg + naltrexone 2.4 mg, oxycodone 20 mg, and placebo, respectively. After dosing, mean ± SEM of the maximum effect (Emax) on EtCO2 was 37.5 ± 0.6, 40.5 ± 0.8, and 36.9 ± 0.6 mmHg for oxycodone 20 mg + naltrexone 2.4 mg, oxycodone 20 mg, and placebo, respectively. Emax values were significantly lower for oxycodone 20 mg + naltrexone 2.4 mg versus oxycodone 20 mg (p = 0.0005), and not different from placebo (p > 0.05). CONCLUSIONS: This abuse-potential study suggests that naltrexone released from ALO-02 tampering by crushing attenuates oxycodone-induced increase of EtCO2 in nondependent recreational opioid users.

Intravenous abuse potential study of oxycodone alone or in combination with naltrexone in nondependent recreational opioid users.

BACKGROUND: ALO-02, comprising pellets of extended-release oxycodone surrounding sequestered naltrexone, is intended to deter abuse. OBJECTIVE: Determine the abuse potential of intravenous oxycodone combined with naltrexone, which represents simulated crushed ALO-02 in solution, compared with intravenous oxycodone in nondependent, recreational opioid users. METHODS: A randomized, double-blind, placebo-controlled, three-way crossover study with naloxone challenge, drug discrimination, and treatment phases. Intravenous treatments included oxycodone hydrochloride 20 mg, oxycodone hydrochloride 20 mg plus naltrexone hydrochloride 2.4 mg (simulated crushed ALO-02 20 mg/2.4 mg), or placebo (0.9% sodium chloride for injection). Primary end points were peak effects (Emax) and area under the effects curve within 2 h postdose (AUE0-2h) on drug liking and high visual analog scales. RESULTS: Thirty-three participants were randomized into treatment phase, and 29 completed all treatments. Study validity was confirmed with statistically significant differences in Emax for drug liking and high (p < 0.0001) between intravenous oxycodone and placebo. Intravenous simulated crushed ALO-02 resulted in significantly lower scores than oxycodone on drug liking (Emax: 58.2 vs. 92.4; AUE0-2h: 104.3 vs. 152.4) and high (Emax: 17.2 vs. 93.1; AUE0-2h: 12.0 vs. 133.6), respectively (p < 0.0001, all comparisons). More participants experienced adverse events after intravenous oxycodone (n = 27 [90%]) versus intravenous simulated crushed ALO-02 (n = 4 [12.5%]) or placebo (n = 2 [6.5%]). CONCLUSION: Intravenous administration of simulated crushed ALO-02 resulted in significantly lower abuse potential, as assessed by subjective ratings of drug liking and high, than intravenous oxycodone in nondependent, recreational opioid users. This suggests that injection of ALO-02 may not be as desirable to recreational opioid users compared with oxycodone taken for nonmedical reasons.

Pharmacoscintigraphy studies to assess the feasibility of a controlled release formulation of ziprasidone.

Ziprasidone, like many BCS Class II drugs with low intrinsic solubility and a strong tendency to crystallize from supersaturated solutions, presents significant technical challenges when developing an oral controlled release dosage form. In order to achieve acceptable bioavailability and prolonged exposures for once-daily dosing, good colonic absorption and a reliable controlled release (CR) technology are necessary. To this end, a novel solubilized drug form--coated crystals made by spray drying (CCSD), was formulated and progressed into human clinical studies. This report describes studies of colonic absorption for the CCSD using the Enterion™ capsule and a pharmacoscintigraphy study in which the CCSD was orally administered via a radiolabelled osmotic tablet formulation. These studies demonstrated that the probability of achieving the required drug solubilization in the colon with the CCSD concept and thereby the desired once daily pharmacokinetic profile was extremely low.

A randomized double-blind, placebo-controlled efficacy and safety study of ALO-02 (extended-release oxycodone surrounding sequestered naltrexone) for moderate-to-severe chronic low back pain treatment.

The objective of this multicenter, double-blind, placebo-controlled, randomized withdrawal study was to evaluate the efficacy and safety of ALO-02, an abuse-deterrent formulation containing pellets of extended-release oxycodone hydrochloride (HCl) surrounding sequestered naltrexone HCl, compared with placebo in the treatment of moderate-to-severe chronic low back pain. An open-label titration period in which all patients received ALO-02 was followed by a double-blind treatment period where patients meeting treatment response criteria were randomized to either a fixed dose of ALO-02 or placebo. Daily average low back pain was assessed using an 11-point numeric rating scale (NRS)-Pain. Of the 663 patients screened, 410 received ALO-02 during the open-label conversion and titration period and 281 patients were randomized to the double-blind treatment period (n = 134, placebo; n = 147, ALO-02). Change in the mean NRS-Pain score from randomization baseline to the final 2 weeks of the treatment period was significantly different favoring ALO-02 compared with placebo (P = 0.0114). Forty-four percent of patients treated with placebo and 57.5% of patients treated with ALO-02 reported ≥30% improvement in weekly average NRS-Pain scores from screening to the final 2 weeks of the treatment period (P = 0.0248). In the double-blind treatment period, 56.8% of patients in the ALO-02 group and 56.0% of patients in the placebo group experienced a treatment-emergent adverse event (TEAE). The most common treatment-related TEAEs for ALO-02 during the treatment period were nausea, vomiting, and constipation, consistent with opioid therapy. ALO-02 has been demonstrated to provide significant reduction of pain in patients with chronic low back pain and has a safety profile similar to other opioids.

The pharmacokinetics of oxycodone and its metabolites following single oral doses of Remoxy®, an abuse-deterrent formulation of extended-release oxycodone, in patients with hepatic or renal impairment.

OBJECTIVE: Remoxy® (Pain Therapeutics, Inc., Austin, TX) is an abuse-deterrent formulation of extended-release oxycodone. The effects of renal or hepatic impairment on the pharmacokinetics (PK) of single, oral doses of Remoxy 20 or 10 mg, respectively, were assessed in two phase 1 studies in subjects aged 18-80 years. METHODS: PK parameters included maximum plasma concentration (C(max)) and area under the concentration-time curve from time 0 to the last quantifiable concentration (AUC(0-t)), and extrapolated to infinity (AUCinf). Adverse events (AEs) were monitored. RESULTS: Mean (SD) oxycodone Cmax values following Remoxy 20-mg administration were 17.6 (9.1), 21.9 (11.2), 25.9 (18.2), and 31.6 (14.5) ng/mL and AUC0-t values were 210.7 (82.1), 271.6 (83.3), 299.5 (76.3), and 493.5 (175.9) ng·h/mL in subjects with normal or mild (n = 6 each), moderate (n = 5), and severely impaired renal function (n = 6), respectively. Mean (SD) oxycodone Cmax following Remoxy 10-mg administration was 7.6 (3.3), 7.8 (2.3), and 13.1 (5.3) ng/mL and AUC(0-t) was 105.7 (49.5), 134.7 (38.3), and 218.0 (74.1) ng·h/mL in subjects with normal, mild, and moderately impaired hepatic function (n = 6 each), respectively. Differences in exposure values between the different renal and hepatic groups were significant. Treatment-emergent AEs were reported by 14.3, 66.7, 66.7, and 50.0 percent of subjects with normal, mild, moderate, and severely impaired renal function, respectively, and by 50.0, 33.3, and 66.7 percent of subjects with normal, mild, and moderately impaired hepatic function, respectively. CONCLUSIONS: As renal or hepatic function decreased, oxycodone Cmax and AUC(0-t) were up to approximately twofold higher following single, oral doses of extended-release Remoxy. AEs were those typically reported for opioids. Lower doses of Remoxy may thus be safely prescribed to subjects with renal or hepatic impairment.

Effects of ethanol on the pharmacokinetics of extended-release oxycodone with sequestered naltrexone (ALO-02).

BACKGROUND AND OBJECTIVES: ALO-02 capsules, intended to deter abuse, contain pellets of extended-release oxycodone hydrochloride (HCl), an opioid agonist, surrounding sequestered naltrexone HCl, an opioid antagonist. The objective of this study was to determine the effects of administration of ALO-02 with 20 or 40 % ethanol on the pharmacokinetics of oxycodone. METHODS: This was an open-label, single-dose, randomized, three-way crossover study in 18 healthy fasting adults administered ALO-02 20/2.4 mg (oxycodone/naltrexone) with water, 20 % ethanol, or 40 % ethanol, each under naltrexone block. RESULTS: Median time to maximum concentration was 12 h postdose when ALO-02 was administered with water or 20 % ethanol and decreased to 8 h postdose with 40 % ethanol. Geometric mean area under the plasma concentration-time curve (AUC) from time zero extrapolated to infinity (AUC∞) and maximum concentration (Cmax) values were similar for ALO-02 administered with water or 20 % ethanol, and increased by about 13 and 37 %, respectively, for ALO-02 administered with 40 % ethanol versus water. The 90 % confidence intervals (CIs) for AUC∞ and Cmax ratios of ALO-02 with 20 % ethanol versus water were within 80-125 %; upper 90 % CIs were >125 % for ALO-02 with 40 % ethanol versus water. The most common adverse events were mild-to-moderate vomiting, nausea, headache, and somnolence. Incidence of adverse events increased for ALO-02 given with ethanol versus water. CONCLUSIONS: Oxycodone exposures (Cmax) were unaffected when ALO-02 was administered with 20 % ethanol but Cmax increased by 37 % with 40 % ethanol versus water. ALO-02 administered with ethanol under naltrexone block was generally well tolerated.

The pharmacokinetic profile of fesoterodine 8 mg with daytime or nighttime dosing.

PURPOSE: Diurnal variation can affect drug pharmacokinetics. Fesoterodine is a new antimuscarinic drug for the treatment of overactive bladder (OAB). We estimated the relative bioavailability of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine, following nighttime and daytime administration. METHODS: In this randomized, open-label, two-period, two-treatment crossover, single-dose study, healthy subjects received daytime and nighttime oral dosing of fesoterodine 8-mg sustained-release tablets, separated by a minimum 60-h washout period. Blood samples for 5-HMT PK determination were collected before dosing and at specified intervals up to 48 h postdose. Safety was assessed by adverse event (AE) reports. RESULTS: Fourteen subjects completed the study. Plasma concentration versus time profiles (AUC) of 5-HMT were similar for daytime and nighttime dosing. Mean AUC(infinity) 5-HMT values were 47.9 and 51.4 ng h/mL for nighttime and daytime dosing, respectively; the mean time to reach maximum concentration (C(max)) values were 3.9 and 5.0 ng/mL, respectively. Nighttime versus daytime AUC(infinity) and C(max) ratios of 5-HMT were 93 and 79%, respectively; 90% confidence intervals (CIs) indicated equivalence for AUC(infinity) but not for C(max). The median time to reach maximum concentration (T(max)) was 5.0 h for both dosing regimens, and the mean terminal elimination half-life (T((1/2))) was 5.9 and 5.7 h for nighttime and daytime dosing, respectively. Seven treatment-related AEs, most commonly headache, occurred in five subjects. CONCLUSIONS: The AUC values for daytime and nighttime administration of fesoterodine were equivalent. The 21% reduction in the C(max) for nighttime dosing is unlikely to be clinically relevant. No safety issues were apparent. These results support both daytime and nighttime administration of fesoterodine for OAB treatment.

The effects of reformulation: improved therapeutic index.

Antimuscarinic agents are the treatment of choice for overactive bladder syndrome. Due to the development of novel delivery systems, extended-release formulations of oxybutynin, tolterodine, and trospium chloride are now available. In addition to the convenience of once-daily dosing, the new formulations of these commonly prescribed agents have improved their therapeutic index, striking a better balance between efficacy and tolerability.

Effects of food on the clinical pharmacokinetics of anticancer agents: underlying mechanisms and implications for oral chemotherapy.

Pharmacokinetic interactions between food and orally administered drugs involve changes mainly in the absorption and metabolism of a drug, and may have clinical implications. Such interactions, in particular, may be of major clinical significance for cancer chemotherapy since the majority of anticancer agents are toxic, have a low therapeutic index and are administered long term, most often in combination with other cytotoxic agents. The purpose of this review is to compare the pharmacokinetic profiles of various anticancer drugs, including chemopreventive agents that have been examined previously in fasted and fed conditions, and to discuss the underlying basis/mechanisms of food effect in light of a drug's physicochemical and pharmacokinetic properties. Clinical pharmacokinetic parameters such as maximum concentration, area under the concentration-time curve, time to maximum concentration and half-life for each drug are compared in fasted and fed states, and specific dietary recommendations are summarised accordingly. In addition, the effects of food on the metabolite kinetics and pharmacodynamic responses, and the potential role of food effect in the modulation of oral biovariability and multidrug resistance have been extensively discussed. Overall, this comprehensive pharmacokinetic analysis indicates that a broad spectrum of food effects is seen among anticancer agents because of diverse factors regulating each drug's oral bioavailability and its interactions with food. The consideration of such effects is important, as it could lead to more rational pharmacological monitoring and possibly improve the oral chemotherapy of cancer in children, adults and the elderly.