Celecoxib-tramadol co-crystal in patients with moderate-to-severe pain following bunionectomy with osteotomy: Secondary analyses by baseline pain intensity and use of rescue medication of a phase 3, randomized, double-blind, factorial, active- and placebo-controlled trial.

BACKGROUND: In the randomized, phase 3, SUSA-301 trial, celecoxib-tramadol co-crystal (CTC) provided significantly greater analgesia compared with celecoxib, tramadol, or placebo in adults with acute, moderate-to-severe, postoperative pain. This post hoc, secondary analysis further evaluated the use of rescue medication and the incidence of treatment-emergent adverse events (TEAEs). METHODS: Patients (N = 637) were randomized 2:2:2:1 to receive oral CTC 200 mg twice daily (BID; n = 184), tramadol 50 mg four times daily (QID; n = 183), celecoxib 100 mg BID (n = 181), or placebo QID (n = 89). Post hoc analyses were conducted on the use of rescue medications up to 4 and 48 h post-study drug dose, stratified by baseline pain intensity (moderate/severe), and on the incidence of TEAEs, stratified by rescue medication use. RESULTS: A significantly lower proportion of patients received any rescue medication within 4 h post-study dose with CTC (49.5%) versus tramadol (61.7%, p = 0.0178), celecoxib (65.2%, p = 0.0024), and placebo (75.3%, p = 0.0001); this was also seen for oxycodone use. Fewer patients in the CTC group received ≥3 doses of rescue medication compared with the other groups, irrespective of baseline pain intensity. In patients who did not receive opioid rescue medication, CTC was associated with a lower incidence of nausea and vomiting TEAEs versus tramadol alone. In patients who received rescue oxycodone, the incidence of nausea was similar in the CTC and tramadol groups, and higher versus celecoxib and placebo. CONCLUSION: Celecoxib-tramadol co-crystal was associated with reduced rescue medication use and an acceptable tolerability profile compared with tramadol or celecoxib alone in adults with acute, moderate-to-severe, postoperative pain.

Co-crystal of Tramadol-Celecoxib Versus Tramadol or Placebo for Acute Moderate-to-Severe Pain After Oral Surgery: Randomized, Double-Blind, Phase 3 Trial (STARDOM1).

INTRODUCTION: Co-crystal of tramadol-celecoxib (CTC) is the first analgesic co-crystal for acute pain. This completed phase 3 multicenter, double-blind trial assessed the efficacy and safety/tolerability of CTC in comparison with that of tramadol in the setting of moderate-to-severe pain up to 72 h after elective third molar extraction requiring bone removal. METHODS: Adults (n = 726) were assigned randomly to five groups (2:2:2:2:1): orally administered twice-daily CTC 100 mg (44 mg rac-tramadol hydrochloride/56 mg celecoxib; n = 164), 150 mg (66/84 mg; n = 160) or 200 mg (88/112 mg; n = 160); tramadol 100 mg four times daily (n = 159); or placebo four times daily (n = 83). Participants in CTC groups also received twice-daily placebo. The full analysis set included all participants who underwent randomization. The primary endpoint was the sum of pain intensity differences over 0 to 4 h (SPID0-4; visual analog scale). Key secondary endpoints included 4-h 50% responder and rescue medication use rates. Safety endpoints included adverse events (AEs), laboratory measures, and Opioid-Related Symptom Distress Scale (OR-SDS) score. RESULTS: All CTC doses were superior to placebo (P < 0.001) for primary and key secondary endpoints. All were superior to tramadol for SPID0-4 (analysis of covariance least squares mean differences [95% confidence interval]: - 37.1 [- 56.5, - 17.6], - 40.2 [- 59.7, - 20.6], and - 41.7 [- 61.2, - 22.2] for 100, 150, and 200 mg CTC, respectively; P < 0.001) and 4-h 50% responder rate. Four-hour 50% responder rates were 32.9% (CTC 100 mg), 33.8% (CTC 150 mg), 40.6% (CTC 200 mg), 20.1% (tramadol), and 7.2% (placebo). Rescue medication use was lower in the 100-mg (P = 0.013) and 200-mg (P = 0.003) CTC groups versus tramadol group. AE incidence and OR-SDS scores were highest for tramadol alone. CONCLUSIONS: CTC demonstrated superior pain relief compared with tramadol or placebo, as well as an improved benefit/risk profile versus tramadol. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02982161; EudraCT number, 2016-000592-24.

Celecoxib-tramadol co-crystal in patients with moderate-to-severe pain following bunionectomy with osteotomy: A phase 3, randomized, double-blind, factorial, active- and placebo-controlled trial.

BACKGROUND: Celecoxib-tramadol co-crystal (CTC) is a first-in-class analgesic co-crystal of celecoxib and racemic tramadol with an improved pharmacologic profile, conferred by the co-crystal structure, compared with its active constituents administered alone/concomitantly. AIM: We evaluated CTC in moderate-to-severe acute postoperative pain. MATERIALS AND METHODS: This randomized, double-blind, factorial, active- and placebo-controlled phase 3 trial (NCT03108482) was conducted at 6 US clinical research centers. Adults with moderate-to-severe acute pain following bunionectomy with osteotomy were randomized to oral CTC (200 mg [112 mg celecoxib/88 mg rac-tramadol hydrochloride] every 12 h), tramadol (50 mg every 6 h), celecoxib (100 mg every 12 h), or placebo for 48 h. Patients, investigators, and personnel were blinded to assignment. The primary endpoint was the 0-48 h sum of pain intensity differences (SPID0-48) in all randomized patients. Pain intensity was assessed on a 0-10 numerical rating scale (NRS). Safety was analyzed in patients who received study medication. Funded by ESTEVE Pharmaceuticals. RESULTS: In 2017 (March to November), 1323 patients were screened and 637 randomized to CTC (n = 184), tramadol (n = 183), celecoxib (n = 181), or placebo (n = 89). Mean baseline NRS was 6.7 in all active groups. CTC had a significantly greater effect on SPID0-48 (least-squares mean: -139.1 [95% confidence interval: -151.8, -126.5]) than tramadol (-109.1 [-121.7, -96.4]; p < 0.001), celecoxib (-103.7 [-116.4, -91.0]; p < 0.001), or placebo (-74.6 [-92.5, -56.6]; p < 0.001). Total treatment-emergent adverse events (TEAEs) were 358 for CTC and 394 for tramadol. Drug-related TEAEs occurred in 37.7% patients in the CTC group, compared with 48.6% in the tramadol group. There were no serious TEAEs/deaths. CONCLUSION: CTC provided greater analgesia than comparable daily doses of tramadol and celecoxib, with similar tolerability to tramadol. CTC is approved in the United States.

Efficacy and safety of co-crystal of tramadol-celecoxib (CTC) in acute moderate-to-severe pain after abdominal hysterectomy: A randomized, double-blind, phase 3 trial (STARDOM2).

BACKGROUND: STARDOM2 is a randomized, double-blind, phase 3 trial evaluating the efficacy and safety of co-crystal of tramadol-celecoxib (CTC)-a first-in-class analgesic co-crystal comprising racemic tramadol hydrochloride and celecoxib in a supramolecular network that modifies their pharmacokinetic properties-for the management of acute postoperative pain (NCT03062644; EudraCT:2016-000593-38). METHODS: Patients with moderate-to-severe pain following abdominal hysterectomy were randomized 2:2:2:2:2:1 to oral CTC 100 mg (rac-tramadol hydrochloride 44 mg/celecoxib 56 mg) twice daily (BID); CTC 150 mg (66/84 mg) BID; CTC 200 mg (88/112 mg) BID; immediate-release tramadol 100 mg four times daily (QID); celecoxib 100 mg BID; or placebo, for 5 days. The primary endpoint was the sum of pain intensity differences over 0-4 h (SPID0-4 ). Key secondary endpoints were rescue medication use within 4 h, 50% response rate at 4 h, and safety/tolerability. RESULTS: Of 1355 patients enrolled, 1138 were randomized (full analysis set) and 1136 treated (safety analysis set). In the prespecified gatekeeping analysis of SPID0-4 , CTC 200 mg was not superior to tramadol but showed non-inferior efficacy (p < 0.001) that was sustained throughout the 120-h period, despite a 5-day cumulative tramadol administration of 880 mg with CTC 200 mg BID versus 2000 mg with tramadol 100 mg QID. Treatment-emergent adverse events (TEAEs) and severe TEAEs were less common with CTC 200 mg versus tramadol. Treatment-related TEAEs were 14.4% with CTC 200 mg and 23.6% with tramadol. CONCLUSIONS: Although the study did not meet its primary endpoint, CTC 200 mg showed a clinically relevant improvement in overall benefit/risk profile versus tramadol alone, with considerably lower cumulative opioid exposure. SIGNIFICANCE: In the randomized, double-blind, phase 3 STARDOM2 trial-in acute moderate-to-severe pain after abdominal hysterectomy-the novel co-crystal of tramadol-celecoxib (CTC) 200 mg BID was superior to placebo and non-inferior to tramadol 100 mg QID. Although superiority to tramadol was not reached, CTC 200 mg BID exposed patients to lower cumulative opioid (tramadol) doses than tramadol (100 mg QID) alone, with fewer treatment-emergent adverse events. CTC 200 mg thus has a clinically relevant improved benefit/risk profile compared with tramadol alone.

Comparative Bioavailability Study of a Novel Multi-Day Patch Formulation of Rivastigmine (Twice Weekly) with Exelon® Transdermal Patch (Daily)- A Randomized Clinical Trial.

BACKGROUND: Rivastigmine, a reversible AChEI for symptomatic treatment of mild to moderately severe Alzheimer's dementia, is administered once daily transdermal patches, enabling an easier and continuous drug delivery. A novel multi-day (twice week) patch formulation was developed with greater convenience for patients' therapeutic management. OBJECTIVE: To assess the bioequivalence under SS conditions of the multiple-day rivastigmine transdermal patch (Test Product, RID-TDS) in comparison to the once-daily Exelon® transdermal patch (Reference Product), both at a release rate of 9.5 mg/24 h. DESIGN: Single-center, open-label, randomized, multiple-dose study in healthy male adults in a 2- period, 2-sequence-crossover design with multiple applications. METHODS: Patches were applied on 11 consecutive days for Exelon® and a 4-3-4-day regimen for the multiday test patch (RID-TDS), separated by a 14-day wash-out period. The safety, local tolerability and inhibitory effect of rivastigmine on plasma BuChE activity were also evaluated. RESULTS: 57 subjects completed the study according to the protocol. Calculated point estimates and 90% CI for all primary parameters (AUC96-264, Cmax96-264 and Cmin96-264) were within the predefined acceptance interval of 80.00-125.00%. They were 113.64% (107.33-120.33), 105.14% (98.38- 112.38) and 107.82% (97.78-118.89) respectively. Satisfactory adhesion (CI of mean adhesion above 90%) was demonstrated for RID-TDS but not for Exelon®. CONCLUSION: Bioequivalence was demonstrated between RID-TDS mg twice a week and Exelon® once daily in SS. Patch adhesion favored RID-TDS despite the longer dosing interval. Both products were well tolerated.

Bioavailability Study of a Transdermal Patch Formulation of Rivastigmine Compared with Exelon in Healthy Subjects.

BACKGROUND AND OBJECTIVES: Rivastigmine is a reversible cholinesterase inhibitor indicated for the treatment of all stages of Alzheimer's disease (AD). Transdermal patch formulation allows smooth and continuous drug delivery. Its tolerability, efficacy and convenience of use increase treatment compliance. This study was designed to evaluate the bioavailability and to assess the bioequivalence of two rivastigmine transdermal patches at steady state (RIV-TDS Test Product versus Exelon Marketed Reference Product), with a release rate of 13.3 mg/24 h, after multiple patch applications. As secondary objectives, safety, patch adhesion and skin irritation were evaluated. METHODS: This was an open-label, randomized, balanced, two-period, two-sequence, cross-over study of healthy adults (n = 31). The treatment period consisted of two 5-day study periods during which consecutive daily application of the investigational patches with a release rate of 13.3 mg/24 h rivastigmine took place. Serial blood samples were collected to measure plasma concentrations. Adhesion and skin irritation assessments were performed after application of patches. RESULTS: Point estimates and 90% confidence intervals of pharmacokinetic parameters at steady state, viz. area under the plasma concentration versus time curve from dosing time to the end of the dosing interval τ (profile day) at steady state [AUC0-τ,ss] (97.4; 88.8-106.9), maximum plasma concentration within the dosing interval τ (profile day) at steady state [Cmax,ss] (99.6; 90.4-109.7) and trough plasma concentration at the end of the dosing interval τ (profile day) at steady state [Cτ,ss] (96.8; 86.2-108.9), demonstrated that both patches were bioequivalent. Evaluation of patch adhesion showed better skin adherence for RIV-TDS as well as dermal response scores (skin tolerability after removal). CONCLUSIONS: For both products, bioequivalence was shown and systemic tolerability was in accordance with the safety profile of the drug substance. The trial is registered in ClinicalTrials.gov: NCT03573050 and EudraCT: 2018-000968-28.

Celecoxib-tramadol co-crystal: A Randomized 4-Way Crossover Comparative Bioavailability Study.

PURPOSE: Celecoxib-tramadol co-crystal (CTC) is a first-in-class co-crystal of celecoxib and racemic tramadol. This Phase 1 bioavailability study compared single-dose pharmacokinetic (PK) parameters of CTC with those of the individual reference products from the United States, immediate-release celecoxib and tramadol, taken alone and simultaneously to determine their systemic exposure. METHODS: This was a single-center, randomized, single-dose, open-label, 4-period, 4-sequence, crossover study conducted in healthy subjects between October and December 2016. Study treatments included 200-mg CTC (equivalent to 112-mg celecoxib and 88-mg tramadol; Treatment-1); 100-mg tramadol (Treatment-2); 100-mg celecoxib (Treatment-3); and 100-mg celecoxib plus 100-mg tramadol (Treatment-4). The PK parameters of interest were Cmax, AUC0-T, and AUC0-∞, which were also calculated normalized to the dose. Tmax was only considered as supportive. The statistical analysis was based on a parametric analysis of variance model of the PK parameters; the two-sided 90% CI of the ratio of geometric mean values for the Cmax, AUC0-T, and AUC0-∞ was based on ln-transformed data, and Tmax was rank-transformed. FINDINGS: Thirty-six subjects aged 18 to 55 years (21 male subjects, 15 female subjects; mean age, 35 years) participated in the study. Celecoxib from CTC presented a lower Cmax, reduced AUCs, and a faster Tmax. The interference in celecoxib absorption when celecoxib and tramadol are administered together was minimized with the CTC. For Treatment-1, -3, and -4, celecoxib PK parameters were 259, 318, and 165 ng/mL (Cmax), respectively; 1930, 2348, and 1929 ng • h/mL (AUC0-T); and 1.5, 3.0, and 2.5 hours (Tmax). Tramadol and its active metabolite O-desmethyl tramadol from CTC presented lower Cmax and AUCs as well as a longer Tmax. Tramadol/O-desmethyl tramadol PK parameters for Treatment-1, -2, and -4 were 214/55, 305/78, and 312/78 ng/mL for Cmax; 2507/846, 2709/965, and 2888/1010 ng • h/mL for AUC0-T; and 3.0/4.0, 2.0/2.5, and 1.9/2.5 hours for Tmax. Reported adverse events (none unexpected) occurred more frequently with Treatment-2 and Treatment-4. IMPLICATIONS: The aim of this study was to compare the PK profile of the US-marketed tramadol and celecoxib products with CTC to determine their systemic exposure and to validate the dosing regimen for a subsequent pivotal factorial Phase 3study. PK parameters of each active component in CTC were favorably modified by co-crystallization and did not result in higher systemic exposure compared with US-marketed celecoxib, tramadol, and their concomitant administration. © 2021 Elsevier HS Journals, Inc.

Co-crystal of Tramadol-Celecoxib in Patients with Moderate to Severe Acute Post-surgical Oral Pain: A Dose-Finding, Randomised, Double-Blind, Placebo- and Active-Controlled, Multicentre, Phase II Trial.

BACKGROUND: Co-crystal of tramadol-celecoxib (CTC), containing equimolar quantities of the active pharmaceutical ingredients (APIs) tramadol and celecoxib (100 mg CTC = 44 mg rac-tramadol hydrochloride and 56 mg celecoxib), is a novel API-API co-crystal for the treatment of pain. We aimed to establish the effective dose of CTC for treating acute pain following oral surgery. METHODS: A dose-finding, double-blind, randomised, placebo- and active-controlled, multicentre (nine Spanish hospitals), phase II study (EudraCT number: 2011-002778-21) was performed in male and female patients aged ≥ 18 years experiencing moderate to severe pain following extraction of two or more impacted third molars requiring bone removal. Eligible patients were randomised via a computer-generated list to receive one of six single-dose treatments (CTC 50, 100, 150, 200 mg; tramadol 100 mg; and placebo). The primary efficacy endpoint was the sum of pain intensity difference (SPID) over 8 h assessed in the per-protocol population. RESULTS: Between 10 February 2012 and 13 February 2013, 334 patients were randomised and received study treatment: 50 mg (n = 55), 100 mg (n = 53), 150 mg (n = 57), or 200 mg (n = 57) of CTC, 100 mg tramadol (n = 58), or placebo (n = 54). CTC 100, 150, and 200 mg showed significantly higher efficacy compared with placebo and/or tramadol in all measures: SPID (0-8 h) (mean [standard deviation]): - 90 (234), - 139 (227), - 173 (224), 71 (213), and 22 (228), respectively. The proportion of patients experiencing treatment-emergent adverse events was lower in the 50 (12.7% [n = 7]), 100 (11.3% [n = 6]), and 150 (15.8% [n = 9]) mg CTC groups, and similar in the 200 mg (29.8% [n = 17]) CTC group, compared with the tramadol group (29.3% [n = 17]), with nausea, dizziness, and vomiting the most frequent events. CONCLUSION: Significant improvement in the benefit-risk ratio was observed for CTC (doses ≥ 100 mg) over tramadol and placebo in the treatment of acute pain following oral surgery. FUNDING: Laboratorios del Dr. Esteve, S.A.U.

Efficacy of a Novel Sigma-1 Receptor Antagonist for Oxaliplatin-Induced Neuropathy: A Randomized, Double-Blind, Placebo-Controlled Phase IIa Clinical Trial.

This trial assessed the efficacy of MR309 (a novel selective sigma-1 receptor ligand previously developed as E-52862) in ameliorating oxaliplatin-induced peripheral neuropathy (oxaipn). A discontinuous regimen of MR309 (400 mg/day, 5 days per cycle) was tested in patients with colorectal cancer receiving FOLFOX in a phase II, randomized, double-blind, placebo-controlled, multicenter clinical trial. Outcome measures included changes in 24-week quantitative measures of thermal sensitivity and total neuropathy score. In total, 124 patients were randomized (1:1) to MR309 or placebo. Sixty-three (50.8%) patients withdrew prematurely before completing 12 planned oxaliplatin cycles. Premature withdrawal because of cancer progression was less frequent in the MR309 group (7.4% vs 25.0% with placebo; p = 0.054). MR309 significantly reduced cold pain threshold temperature [mean treatment effect difference (SE) vs placebo: 5.29 (1.60)°C; p = 0.001] and suprathreshold cold stimulus-evoked pain intensity [mean treatment effect difference: 1.24 (0.57) points; p = 0.032]. Total neuropathy score, health-related quality-of-life measures, and nerve-conduction parameters changed similarly in both arms, whereas the proportion of patients with severe chronic neuropathy (National Cancer Institute Common Terminology Criteria for Adverse Events ≥ 3) was significantly lower in the MR309 group (3.0% vs 18.2% with placebo; p = 0.046). The total amount of oxaliplatin delivered was greater in the active arm (1618.9 mg vs 1453.8 mg with placebo; p = 0.049). Overall, 19.0% of patients experienced at least 1 treatment-related adverse event (25.8% and 11.9% with MR309 and placebo, respectively). Intermittent treatment with MR309 was associated with reduced acute oxaipn and higher oxaliplatin exposure, and showed a potential neuroprotective role for chronic cumulative oxaipn. Furthermore, MR309 showed an acceptable safety profile.

Pharmacokinetics of multiple doses of co-crystal of tramadol-celecoxib: findings from a four-way randomized open-label phase I clinical trial.

AIM: We compared the pharmacokinetic (PK) profiles of co-crystal of tramadol-celecoxib (CTC) vs. each reference product (alone and in open combination) after single (first dose) and multiple dosing. METHODS: Healthy adults aged 18-50 years received, under fasted conditions, 15 twice-daily doses of the following treatments (separated by ≥14-day washout): 200 mg immediate-release (IR) CTC (equivalent to 88 mg tramadol and 112 mg celecoxib; treatment 1); 100 mg IR tramadol (treatment 2), 100 mg celecoxib (treatment 3); and 100 mg IR tramadol and 100 mg celecoxib (treatment 4). The treatment sequence was assigned by computer-generated randomization. PK parameters were calculated using non-compartmental analysis. Parameters for CTC were adjusted according to reference product dose. RESULTS: A total of 30 subjects (20 males, mean age 35 years) were included. Multiple-dose tramadol PK parameters for treatments 1, 2 and 4, respectively, were 551, 632 and 661 ng ml-1 [mean maximum plasma concentration (Cmax )]; 4796, 4990 and 5284 ng h ml-1 (area under the plasma concentration-time curve over the dosing interval at steady state); and 3.0, 2.0 and 2.0 h (median time to Cmax at steady state). For treatments 1, 3 and 4, multiple-dose celecoxib PK parameters were 445, 536 and 396 ng ml-1 ; 2803, 3366 and 2897 ng h ml-1 ; and 2.0, 2.0 and 3.0 h. Single-dose findings were consistent with multiple-dose data. Types of adverse events were consistent with known reference product safety profiles. CONCLUSION: After single (first dose) and multiple dosing, PK parameters for each active pharmaceutical ingredient in CTC were modified by co-crystallization compared with reference products alone or in open combination.

Single-dose pharmacokinetics of co-crystal of tramadol-celecoxib: Results of a four-way randomized open-label phase I clinical trial in healthy subjects.

AIMS: Co-crystal of tramadol-celecoxib (CTC) is a novel co-crystal molecule containing two active pharmaceutical ingredients under development by Esteve (E-58425) and Mundipharma Research (MR308). This Phase I study compared single-dose pharmacokinetics (PK) of CTC with those of the individual reference products [immediate-release (IR) tramadol and celecoxib] alone and in open combination. METHODS: Healthy adults aged 18-55 years were orally administered four treatments under fasted conditions (separated by 7-day wash-out period): 200 mg IR CTC (equivalent to 88 mg tramadol and 112 mg celecoxib; Treatment 1); 100 mg IR tramadol (Treatment 2); 100 mg celecoxib (Treatment 3); and 100 mg IR tramadol and 100 mg celecoxib (Treatment 4). Treatment sequence was assigned using computer-generated randomization. PK parameters were calculated using noncompartmental analysis with parameters for CTC adjusted according to reference product dose (100 mg). RESULTS: Thirty-six subjects (28 male, mean age 36 years) participated. Tramadol PK parameters for Treatments-1, -2 and -4, respectively, were 263, 346 and 349 ng ml-1 (mean maximum plasma concentration); 3039, 2979 and 3119 ng h ml-1 (mean cumulative area under the plasma concentration-time curve); and 2.7, 1.8 and 1.8 h (median time to maximum plasma concentration). For Treatments 1, 3 and 4, the respective celecoxib PK parameters were 313, 449 and 284 ng ml-1 ; 2183, 3093 and 2856 ng h ml-1 ; and 1.5, 2.3 and 3.0 h. No unexpected adverse events were reported. CONCLUSION: PK parameters of each API in CTC were modified by co-crystallization compared with marketed formulations of tramadol, celecoxib, and their open combination.

Safety, tolerability and pharmacokinetics of single and multiple doses of a novel sigma-1 receptor antagonist in three randomized phase I studies.

AIM: To assess the safety, tolerability, pharmacodynamics and pharmacokinetics in healthy subjects of a novel, highly selective, sigma-1 receptor antagonist (S1RA). METHODS: Three randomized, double-blind, placebo-controlled trials evaluated single oral doses (5-500 mg, study 101; 500-800 mg, study 106) and multiple doses (50-400 mg once daily for 8 days, study 102) of S1RA. Safety and tolerability were assessed by adverse event reporting, clinical laboratory, physical examinations, vital signs and electrocardiography, including Holter monitoring. Pharmacodynamic assessments included computerized cognitive testing. Plasma samples were analyzed using validated HPLC-MS/MS methods. RESULTS: One hundred and seventy-five subjects were enrolled. Single and multiple doses were safe and well tolerated, with no serious adverse events. The most common side effects were headache and dizziness. The highest single doses were associated with some mild to moderate transient CNS effects. The maximum tolerated dose was not reached. There were no clinically significant changes in the electrocardiogram (ECG), 24 h Holter monitoring, or in vital signs and laboratory assessments. Subjective CNS pharmacodynamics evaluations showed no relevant differences vs. placebo. Cognitive testing showed no effects on visual memory, executive function, attention or somnolence, while revealing some transient slowing of response for simple reaction time and choice reaction time at 2 h following the administration of higher doses. A fast absorption, rapid distribution and slow elimination were observed (t(max) 0.75-2.0 h, t(1/2) compatible with once a day administration) and steady-state was reached. No gender differences were observed. CONCLUSIONS: S1RA exhibited an acceptable safety, tolerability, pharmacodynamic and pharmacokinetic profile in healthy subjects over the dose range studied.

Suspected cross-hepatotoxicity of flutamide and cyproterone acetate.

Flutamide and cyproterone acetate (CPA) are both oral anti-androgens commonly used to treat advanced prostatic cancer. We report a case of drug-induced hepatotoxicity after consecutive treatment with flutamide and CPA. A 78-year-old male with advanced prostatic adenocarcinoma had been treated with flutamide 750 mg/day p.o. and leuproleride acetate 22.5 mg/3 months i.m. Three months later, the patient complained of choluria and jaundice. Laboratory examination revealed severe hepatocellular insufficiency. Flutamide-induced hepatotoxicity was suspected and therefore flutamide was withdrawn. His liver function abnormalities resolved after drug discontinuation. He was subsequently started on CPA 150 mg/day and again developed hepatotoxicity with severe hepatocellular impairment, which completely recovered after drug discontinuation. Other causes of acute liver failure were appropriately ruled out in both episodes and there was no evidence of active prostate cancer or liver metastases in both episodes. The occurrence of hepatotoxicity associated with flutamide and CPA on separated occasions suggests the possibility of a common mechanism of injury. It may become necessary to reassess the common practice of switching to another anti-androgen when hepatotoxicity appears. A closer monitoring of liver enzymes might be necessary in such cases, as an increased risk of a new severe hepatotoxicity event cannot be ruled out.