PK/PD analysis of trazodone and gabapentin in neuropathic pain rodent models: Translational PK-PD modeling from nonclinical to clinical development.

A pharmacokinetic/pharmacodynamic (PK/PD) model was developed to describe the time course of writhings after intraperitoneal injection of acetic acid in mice. The model was applied to investigate the antinociceptive effect of trazodone and gabapentin alone and in combination. Writhings time course was described by a transit compartment model with the delay due to the transit of the acetic acid being represented by a chain of intermediate compartments. In the drug-treated animals, the number of writhings decreases according to a k2 factor linking drug concentration and antinociceptive effect. Compounds' potency parameters were 10.9 and 0.0459 L/µmoles/min for trazodone and gabapentin, respectively, indicating a much higher in vivo potency of trazodone in the PD writhing test. The PK/PD parameters were used to simulate the expected writhing counts in mice at combined doses without efficacy alone, assuming pharmacological additivity. Simulation results indicated that, at low dose combinations, experimental data were mostly below the simulated writhings median, suggesting possible synergic effect. Such hypothesis was tested by adding the γ parameter in the PK/PD model to represent the deviation from the assumption of no-interaction, leading to a reduction of the objective function compared to the additive model. On this basis, several simulations were performed to identify possible starting dose combinations of trazodone and gabapentin in humans, by selecting doses yielding systemic exposures close to those being synergic in the mouse. Simulations indicated that doses of 50-100 mg trazodone could enhance gabapentin antinociceptive effect in humans, supporting the development of a low dose combination for optimal analgesia treatment.

Estimation of brain receptor occupancy for trazodone immediate release and once a day formulations.

Trazodone is approved for the treatment of major depressive disorders, marketed as immediate release (IR), prolonged release, and once a day (OAD) formulation. The different formulations allow different administration schedules and may be useful to facilitate patients' compliance to the antidepressant treatment. A previously verified physiologically-based pharmacokinetic model based on in vitro and in vivo information on trazodone pharmacokinetics was applied, aiming at predicting brain receptor occupancy (RO) after single and repeated dosing of the IR formulation and repeated dosing of the OAD formulation in healthy subjects. Receptors included in the simulations were selected using static calculations of RO based on the maximum unbound brain concentration (Cmax,brain,u ) of trazodone for each formulation and dosing scheme, resulting in 16 receptors being simulated. Seven receptors were simulated for the IR low dose formulation (30 mg), with similar tonset and duration of coverage (range: 0.09-0.25 h and 2.1->24 h, respectively) as well as RO (range: 0.64-0.92) predicted between day 1 and day 7 of dosing. The 16 receptors evaluated for the OAD formulation (300 mg) showed high RO (range: 0.97-0.84 for the receptors also covered by the IR formulation and 0.73-0.48 for the remaining) correlating with affinity and similar duration of time above the target threshold to the IR formulation (range: 2->24 h). The dose-dependent receptor coverage supports the multimodal activity of trazodone, which may further contribute to its fast antidepressant action and effectiveness in controlling different symptoms in depressed patients.

Impact of Lurasidone and Other Antipsychotics on Body Weight: Real-World, Retrospective, Comparative Study of 15,323 Adults with Schizophrenia.

PURPOSE: The primary objectives were to describe weight changes following initiation of lurasidone versus other antipsychotics and estimate the risk of clinically relevant (≥7%) weight changes. PATIENTS AND METHODS: This retrospective, longitudinal comparative cohort study was based on electronic medical records (EMRs) of United States (US) adult patients with schizophrenia who were prescribed lurasidone or other antipsychotics as monotherapy between 1 April 2013 and 30 June 2019. RESULTS: Overall, the study included 15,323 patients with a diagnosis of schizophrenia; 6.1% of patients received lurasidone, 60.4% received antipsychotics associated with a medium-high risk of weight gain (clozapine, olanzapine, quetiapine, risperidone, paliperidone) and 33.5% received antipsychotics with a low risk of weight gain (aripiprazole, first-generation antipsychotics, ziprasidone). Lurasidone was associated with the smallest proportion of patients experiencing clinically relevant weight gain and the greatest proportion of patients with clinically relevant weight loss. The risk of clinically relevant weight gain was numerically higher with all antipsychotics versus lurasidone and was statistically significant for olanzapine (hazard ratio [HR]=1.541; 95% confidence interval [CI]=1.121; 2.119; p=0.0078) versus lurasidone. The likelihood of ≥7% weight loss was significantly greater with lurasidone versus all antipsychotics (p<0.05), except ziprasidone. CONCLUSION: This real-world study suggests that lurasidone has a lower risk of clinically relevant weight gain and a higher likelihood of clinically relevant weight loss than other commonly used antipsychotics.

Intravenous paracetamol in comparison with ibuprofen for the treatment of patent ductus arteriosus in preterm infants: a randomized controlled trial.

Our aim was to assess the efficacy and safety of intravenous (i.v.) paracetamol vs. i.v. ibuprofen for the treatment of hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. This is a multicenter randomized controlled study. Infants with a gestational age of 25+0-31+6 weeks were randomized to receive i.v. paracetamol (15 mg/kg/6 h for 3 days) or i.v. ibuprofen (10-5-5 mg/kg/day). The primary outcome was the closure rate of hsPDA after the first treatment course with paracetamol or ibuprofen. Secondary outcomes included the constriction rate of hsPDA, the re-opening rate, and the need for surgical closure. Fifty-two and 49 infants received paracetamol or ibuprofen, respectively. Paracetamol was less effective in closing hsPDA than ibuprofen (52 vs. 78%; P = 0.026), but the constriction rate of the ductus was similar (81 vs. 90%; P = 0.202), as confirmed by logistic regression analysis. The re-opening rate, the need for surgical closure, and the occurrence of adverse effects were also similar.Conclusions: Intravenous paracetamol was less effective in closing hsPDA than ibuprofen, but due to a similar constriction effect, its use was associated with the same hsPDA outcome. These results can support the use of i.v. paracetamol as a first-choice drug for the treatment of hsPDA.Trial registration: Clinicaltrials.gov : NCT02422966, Date of registration: 04/09/2015; EudraCT no: 2013-003883-30. What is Known: • The successful closure of patent ductus arteriosus with oral paracetamol has been recently reported in several preterm infants, but only one randomized controlled study investigated the efficacy of intravenous paracetamol. What is New: • Intravenous paracetamol is less effective in closing hsPDA than ibuprofen, but have a similar constriction effect. • These results can support the use of i.v. paracetamol as a first-choice drug for the treatment of hsPDA.

A novel rizatriptan oral gel formulation: Bioavailability and bioequivalence.

OBJECTIVES: To establish the relative bioavailability between a newly developed oral gel and a marketed oral lyophilisate-containing rizatriptan benzoate. MATERIALS AND METHODS: A total of 47 out of 48 healthy subjects, aged 34 ± 10 (SD) years and body mass index 24.7 ± 3.3 (SD) kg/m2 completed this single-center, open-label, randomized, 2-period cross-over trial with single-dose fasted administrations. Intake of both investigational products was separated by a washout period of at least 6 days. For pharmacokinetic evaluation, blood samples were withdrawn until 24 hours post dose. A validated liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was applied for the determination of rizatriptan in plasma. The lower limit of quantitation (LLOQ) was 0.100 ng/mL. Adverse events (AEs) were descriptively analyzed in the study population. Palatability of the new product was investigated based on a questionnaire. RESULTS: The geometric means of the parameters related with the extent of total exposure, i.e., AUC0-tlast and AUC0-∞, were 60.285 ng × h/mL and 60.865 ng × h/mL for test and 62.729 ng × h/mL and 63.312 ng × h/mL for reference, respectively. The geometric means of the peak exposure, i.e., Cmax, were 21.262 ng/mL for test and 21.447 ng/mL for reference. The point estimates (PEs) of the test/reference (T/R) adjusted geometric mean ratios of AUC0-tlast, Cmax, and AUC0-∞ (secondary parameter) were 96.11%, 99.12%, and 96.15%, respectively, and all of them showed 90% confidence intervals (CIs) within the range of 80.00 - 125.00% as suggested by regulatory requirements for bioequivalence assessment. In total, 13 subjects experienced 20 AEs during the trial; the most frequently reported AEs were headache (5 cases) and dizziness (3 cases). No AEs of severe intensity were reported. Palatability assessment of the new product provided sufficient data to discuss its acceptability. CONCLUSION: Bioequivalence was demonstrated in terms of rate and extent of absorption after administration of test and reference products. Concerning the safety evaluation, no negative implications on the possible use of the test formulation could be determined. Based on ratings by the subjects no relevant problem concerning acceptability of the new formulation in particular regarding taste and smell is to be expected.

Effect of 3 Single Doses of Trazodone on QTc Interval in Healthy Subjects.

This study evaluated the effect of 3 doses of a trazodone hydrochloride 6% oral drops solution on the QT interval of healthy volunteers. Subjects were randomly assigned to receive a single dose of trazodone 20 mg, 60 mg, and 140 mg, moxifloxacin 400 mg, and trazodone-matched placebo in 5 periods separated by 7-day washouts, according to a double-blind, crossover study design. Subjects were monitored continuously, and triplicate ECGs were extracted from baseline (predose) until 24 hours postdose. Blood samples for trazodone and moxifloxacin analyses were collected at the same time points. The concentration-QTc relationship assessed on placebo-adjusted change from baseline for Fridericia-corrected QT (ΔΔQTcF) was the primary end point. ΔΔQTcF values of 4.5, 12.3, and 19.8 ms for the 20-, 60-, and 140-mg doses were observed at the corresponding trazodone peak plasma concentrations. The upper bound of the 90%CI exceeded 10 ms for the 60- and the 140-mg doses. Time-matched analysis results were in line with these findings. No significant trazodone effect on heart rate or PR or QRS intervals and no clinically significant new morphological changes were present. In this moxifloxacin-validated ECG trial, trazodone had a modest, dose-dependent effect on cardiac repolarization, with no QTc prolongation observed with the 20-mg dose and an effect exceeding the values set in E14 guideline with the 60- and 140-mg doses. The effect on cardiac repolarization is unlikely to represent a clinical risk for ventricular proarrhythmia, but caution should be used with concomitant use of other medications that prolong QT or increase trazodone exposure.

Efficacy and safety of intravenous paracetamol in comparison to ibuprofen for the treatment of patent ductus arteriosus in preterm infants: study protocol for a randomized control trial.

BACKGROUND: Patent ductus arteriosus (PDA) is one of most common complications in preterm infants. Although ibuprofen represents the first choice for the closure of PDA, this treatment can cause severe gastrointestinal and adverse renal effects and worsen platelet function. The successful closure of the PDA with paracetamol has been recently reported in several preterm infants, and the safety of paracetamol for this use has been suggested by the available data. METHODS/DESIGN: We present the design of a randomized, multicenter, controlled study, whose aim is to assess the effectiveness and safety of intravenous paracetamol in comparison to intravenous ibuprofen for the treatment of PDA in preterm infants. A total of 110 infants born at 25(+0) to 31(+6) weeks of gestational age will be enrolled and randomized to receive paracetamol or ibuprofen (55 patients per group) starting at 24-72 h of life. The primary endpoint of the study is the comparison of the PDA closing rate observed after a 3-day course with paracetamol or ibuprofen. The secondary endpoints include the closure rate of PDA after the second course of treatment with ibuprofen, the re-opening rate of the PDA, the incidence of surgical ligation, and the occurrence of adverse effects. DISCUSSION: The results of this study will provide new information about the possible use of paracetamol in the treatment of PDA. Paracetamol could offer several important therapeutic advantages over current treatment options, and it could become the treatment of choice for the management of PDA, mainly due to its more favorable side effect profile. TRIAL REGISTRATION: Clinicaltrials.gov NCT02422966 . Eudract no. 2013-003883-30.

Penetration of prulifloxacin into sinus mucosa of patients undergoing paranasal sinus elective endoscopic surgery.

The aim of this study was to assess the concentration of ulifloxacin, the active metabolite of prulifloxacin, in sinuses mucosa and plasma of patients with chronic rhinosinusitis, requiring sinus elective endoscopic surgery. Thirty-nine patients (30 males, 9 females; age range 22-77 years) with chronic sinusitis were enrolled, 35 were treated with the investigational medication. Samples from four untreated patients were used to validate the analytical method, while four treated patients dropped out before surgery. One 600 mg prulifloxacin tablet once daily was administered for 5 days before surgery. The last dosing was scheduled from 2 to 12 hours from tissue and plasma sampling. In each patient, two samples of paranasal sinus mucosa (from ethmoid and turbinate, respectively) and one blood sample were collected. Concentrations of ulifloxacin in plasma and sinuses mucosa were measured using validated bioanalytical LC/MS/MS methods. Individual and mean ulifloxacin concentrations in tissues were always higher than the relevant plasma levels. The highest concentrations were observed between 2.5 and 4.5 hours after the last dosing in all districts. The mean tissue/plasma ratios were 2.5 and 3.0 for ethmoid and turbinate, respectively. Data expressed as Area Under the Curves (AUC±SD) showed that ulifloxacin concentrations in the ethmoid were slightly higher (18.68±6.48 µg/g*h) than in turbinate (15.00±2.89 µg/g*h), and definitely higher than in plasma (6.32±1.14 µg/ml*h). The AUC ratios between tissues and plasma were 3.0 for ethmoides and 2.4 for turbinates. One patient reported two treatment-related episodes of diarrhea, which spontaneously resolved after the drug suspension. Results from this study seem to suggest that prulifloxacin showed good distribution in sinus tissues, where it reaches concentrations significantly higher than in plasma. These findings strongly call for confirmatory clinical trials in patients with bacterial rhinosinusitis.

Effects of prulifloxacin on cardiac repolarization in healthy subjects: a randomized, crossover, double-blind versus placebo, moxifloxacin-controlled study.

BACKGROUND AND OBJECTIVE: Prulifloxacin, a broad-spectrum fluoroquinolone, is quantitatively transformed after oral administration into ulifloxacin, the active metabolite. On the basis of preclinical data suggesting that prulifloxacin is not likely to prolong the QT interval, a trial to assess the potential effects of prulifloxacin on QT and corrected QT (QTc) interval in humans was performed. METHODS: Fifty-two healthy subjects were randomized into three groups to receive prulifloxacin 600 mg, moxifloxacin 400mg and placebo once daily for 5 days, using a crossover, double-blind versus placebo, moxifloxacin-controlled study. At baseline and days 1 and 5, three 12-lead digital ECGs were recorded before and up to 24 hours after dosing at nine predefined timepoints. Blood samples were also collected at each treatment timepoint. ECG data were analysed in a blinded manner by a centralized laboratory using skilled readers. QT values were corrected for heart rate using an individual correction method (QTcI) as the primary variable, and Fridericia's method as reference. RESULTS: In forty-eight subjects who completed the study, compared with placebo, prulifloxacin had no relevant effect on cardiac repolarization, with the largest mean QTcI increase being 3.97 ms (one-sided 95% CI 0.01, 7.93), whereas moxifloxacin demonstrated the expected positive effect (maximum mean QTcI increase of 12.0 ms, one-sided 95% CI 8.66, 15.34), thus demonstrating the good sensitivity of the study. A statistically significant correlation between QTcI changes and plasma concentrations was found for moxifloxacin but not for ulifloxacin. CONCLUSION: Prulifloxacin at steady state after therapeutic doses has no significant effects on the QTc interval and thus should prove to have no cardiac liability.

Penetration of prulifloxacin into gynaecological tissues after single and repeated oral administrations.

OBJECTIVE: This study aimed to evaluate the penetration into gynaecological tissues of ulifloxacin, the active metabolite of prulifloxacin, a once-daily fluoroquinolone administered once or in repeated doses. METHODS: This was an open-label, randomised study that included 20 consenting female inpatients (age range 40-65 years) requiring total simple hysterectomy as a result of benign disease. Three groups of patients were enrolled: group A (four patients whose gynaecological tissue samples were used to set up the bioanalytical method); group B (eight patients treated 3 hours before surgery with one 600 mg tablet of prulifloxacin); group C (eight patients treated with prulifloxacin 600 mg once daily for 3 days and undergoing surgery 3 hours after the last dose). Patients to be treated with prulifloxacin were randomly allocated to group B or C. During surgery, samples of blood were collected jointly with healthy tissue removed from the endometrium, proximal fallopian tube, vaginal posterior fornix and portio vaginalis. Ulifloxacin concentrations in plasma and gynaecological tissues were determined by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) bioanalytical method. An intrastudy assessment of the bioanalytical method performance was also conducted for plasma and tissues using calibration and quality control data (spiked samples). RESULTS: Ulifloxacin mean concentrations were always higher in group C than in group B patients, both in plasma (0.76 vs 0.53 microg/mL) and in gynaecological tissues, namely fallopian tube (1.38 vs 0.81 microg/g), posterior fornix (1.48 vs 1.05 microg/g), portio vaginalis (1.46 vs 1.45 microg/g) and endometrium (2.20 vs 1.39 microg/g), as expected after repeated drug administrations. Tissue concentrations observed after repeated administrations were generally higher than the ulifloxacin minimum inhibitory concentrations for pathogens more frequently involved in gynaecological bacterial infections. The mean tissue/plasma ratios ranged between 1.5 and almost 3. CONCLUSION: The results of this study are promising but not fully predictive of clinical or microbiological efficacy for prulifloxacin. There is a need for appropriate clinical trials confirming that prulifloxacin is a useful therapeutic tool in patients with gynaecological bacterial infections.

Effect of ibopamine on aqueous humor production in normotensive humans.

PURPOSE: Ibopamine is a prodrug of epinine (deoxyepinephrine) that exhibits activity at dopaminergic and adrenergic receptors. Topical ocular application has been shown to cause mydriasis without cycloplegia and to increase the rate of aqueous humor flow in normotensive human eyes. Mydriasis can interfere with the measurement of aqueous flow. In this study ibopamine's effect on aqueous humor production was measured while making allowance for the potential artifact caused by its mydriatic effect. METHODS: The effects of topical ibopamine on pupillary diameter, aqueous humor flow measured by fluorophotometry, and intraocular pressure were studied in 24 healthy, blue-eyed humans. Ibopamine was administered with and without the alpha-adrenergic antagonist dapiprazole, and its effects were compared with those of tropicamide, with and without dapiprazole in a double-masked, randomized, crossover design. RESULTS: Ibopamine dilated the pupil from a diameter of 3.7 +/- 0.64 (mean +/- SD, n=24) to 7.7 +/- 0.70 mm. Ibopamine, during its peak mydriasis, was associated with a very large increase in the rate of clearance of topically applied fluorescein from the cornea and anterior chamber, an effect that was not associated with tropicamide during its peak mydriasis. The mydriatic effect of ibopamine was completely blocked by dapiprazole, and the increase in fluorescein clearance was partially blocked. When mydriasis was blocked, ibopamine increased fluorescein clearance by 13% (P<0.0001), which was interpreted as an increased rate of aqueous humor production. Compared with placebo and with the tropicamide control, ibopamine decreased intraocular pressure, despite its stimulation of aqueous humor flow. CONCLUSIONS: Ibopamine is in a specific class of drug, along with pilocarpine, epinephrine, and bimatoprost that in humans increases the rate of aqueous humor flow as measured by fluorophotometry. This effect is partly responsible for its ability to increase intraocular pressure in persons suspected to have abnormally low aqueous humor outflow facility. The transient apparent doubling of aqueous humor flow, measured by fluorescein clearance after administration of ibopamine is an artifact of increased fluorescein clearance through the dilated pupil while accommodation is active.

Pharmacokinetics and tolerability of prulifloxacin after single oral administration.

The pharmacokinetic properties and tolerability of three different strengths of prulifloxacin (CAS 123447-62-1), a new antibacterial agent prodrug of AF3013 (CAS 112984-60-8), have been investigated in a randomized, cross-over study performed in 12 Caucasian male subjects (age range 19-34 years). Prulifloxacin was administered as a single oral dose at the dosages of 300, 450 and 600 mg. Plasma concentrations of the active metabolite AF3013 were determined in blood samples collected before the administration (pre-dose) and at 15, 30, 45 min, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 and 48 h after dosing. Urine samples were also collected. Determination in biological samples was performed using validated and specific HPLC methods. The following parameters were calculated: Cmax, tmax, AUC0-t, AUC0--infinity, t1/2, V/F, Aeut, CLren and fe. The analysis of variance performed on dose-normalized data after logarithmic transformation evidenced no statistically significant differences between the three doses concerning Cmax and AUC. Friedman's test applied to tmax and t1/2 did not show any statistically significant difference between doses. A significant linear relationship between doses and AUC0-infinity was detected (p < 0.05). Very high urinary concentrations and the relatively long terminal half-life (10-12 h) suggest that a once-daily application would show adequate clinical efficacy, especially in urinary infections. The safety profile of the three doses was very good.

Randomized, double-blind study of prulifloxacin versus ciprofloxacin in patients with acute exacerbations of chronic bronchitis.

BACKGROUND: Recently the role of bacteria in acute exacerbations of chronic bronchitis (AECB) as well as antibiotic treatment with selected drugs, especially fluoroquinolones, have been better defined. OBJECTIVE: To assess the efficacy and safety in patients with AECB of prulifloxacin in comparison with ciprofloxacin. METHODS: AECB was defined according to the guidelines for the evaluation of new anti-infective drugs for the treatment of respiratory tract infections (1992). 235 patients took part in the trial; 117 (88 males and 29 females, mean age 64.8 years) received 600 mg prulifloxacin once daily and 118 (91 males and 27 females, mean age 64.5 years) 500 mg ciprofloxacin twice a day, for a duration of 10 days. The study design was randomized, multicenter, double-blind, double-dummy. Efficacy evaluations were performed by comparing pretreatment and posttreatment assessments. The clinical response was determined by 4-point rating scores on cough, dyspnea, and expectoration (volume and appearance). The microbiological response was assessed on sputum specimen. RESULTS: Clinical success was observed in 84.7 and 85% of patients in the prulifloxacin and ciprofloxacin groups, respectively. The 95% confidence interval proved the equivalence of treatments. Both drugs successfully eradicated the most commonly isolated strains, including Haemophilus influenzae, Streptococcus pneumoniae, Klebsiella pneumoniae and Pseudomonas aeruginosa. Both treatments were well tolerated. Adverse drug reactions were always of mild or moderate intensity. CONCLUSION: The study showed that a 10-day course of prulifloxacin is as effective and safe as ciprofloxacin in the treatment of patients with AECB.