Paroxetine mesylate: comparable to paroxetine hydrochloride?

Modulation of biopharmaceutical properties of acidic drugs using cationic counterions: A critical analysis of FDA-approved pharmaceutical salts

Salification has a successful track record in modulating the biopharmaceutical properties of drugs. This is evident from the significant share (40%) of pharmaceutical salts in FDA-approved drugs in the past 80-years. Based on the ionic nature of drugs, the corresponding cationic or anionic counterions are employed for salification. This review aims to provide the contribution of cationic counterions in FDA-approved drugs from 1939 to 2020. The analysis of 80-years data has shown that the 7.1% of the FDA-approved drugs comprise cationic counterions (98 pharmaceutical salts). Heparin sodium is the pioneering drug in the history of pharmaceutical salts that was approved in 1939 as an anticoagulant medication. Inorganic (sodium, calcium, potassium, magnesium, silver), as well as organic (tromethamine, meglumine, erbumine) cationic counterions, were used in FDA-approved drugs with a major share by sodium (76 drugs). The technical superiority of cationic salts over other salt forms and the parent drug is also exemplified using case studies.

Drug Brand Response and Its Impact on Compliance and Efficacy in Depression Patients

Introduction: Patient's response to drug brand is a comprehensive physiological and psychological effect which might impact the compliance and efficacy of drugs. Whether the therapeutic outcome altered on patients with brand response after they experience drug switch is not clear.

Methods: 459 outpatients with mild-to-moderate depression were divided into the imported (joint venture) drug group and the domestic drug group according to their current drug application. Two groups of patients were assessed by drug brand preference questionnaire and medication compliance questionnaire. Patients with brand preference in imported (joint venture) drugs group received rational use of limited medical resource and pharmacoeconomics education, and then switched with domestic drug for 8 weeks. Safety and efficacy were evaluated both before and after the drug switch.

Results: Overall, there were 27% of patients in imported drug group and 35% of patients in domestic drug group have brand response, respectively. About 2/3 patients in both groups showed low or no brand response. The compliance was similar in both groups with no significant difference (6.04 ± 2.08 vs. 4.74 ± 2.13, respectively, P > 0.05). The efficacy of imported drug group was significantly better than of the domestic drug group. Correlation analysis showed that in imported (joint venture) drugs group, medication compliance was closely related with brand response, but negatively correlated with age and duration. In domestic drugs group, medication compliance was independent of brand response, but closely related with education, age, and duration. After drug switch with domestic drug on patients with brand response, patients continued to maintain good antidepressant effect, and no severe adverse reaction occurred.

Conclusion: The results suggested that domestic drugs switch might be feasible for patients using imported drugs with brand response, while providing patients with rational use of drug education and psychological support. The medical staff should focus on medication education to help patients make better use of limited medical resources.

Effect and safety of paroxetine for vasomotor symptoms: systematic review and meta-analysis

BACKGROUND

Paroxetine is the first non-hormone therapy for vasomotor symptoms (VMS) approved based on the results of two phase 3, randomised, placebo-controlled trials by the Food and Drug Administration (FDA) in 2013.

OBJECTIVE

To confirm the effect and safety of paroxetine for vasomotor symptoms (VMS).

SEARCH STRATEGY

MEDLINE, EMBASE, PsycINFO, CENTRAL, WHO International Clinical Trials Registry Platform (ICTRP) and four Chinese databases was searched from the date of their inception to 7 June 2014.

SELECTION CRITERIA

We included RCTs on the effect of paroxetine compared with placebo or no treatment for perimenopausal and postmenopausal women who experienced moderate-to-severe vasomotor symptoms.

DATA COLLECTION AND ANALYSIS

Two reviewers screened records and extracted the information independently. The included studies were appraised by two independent reviewers using the Cochrane risk of bias tool. We synthesised the data in random-effects models and rated the quality of evidence using GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach.

MAIN RESULTS

Five articles with six RCTs (1571 participants) were included. Paroxetine significantly reduced the frequency of hot flushes by 8.86 per week (95% confidence interval (CI) 5.69-12.04, P < 0.00001, I(2)  = 83%) at week 4 and 7.36 per week (95% CI, 4.25-10.46, P < 0.00001, I(2)  = 62%) at week 12. The quality of the evidence on the effect of paroxetine for VMS was moderate.

CONCLUSIONS

There was moderate quality of evidence supporting the effectiveness of paroxetine for vasomotor symptoms; however, it causes nausea and dizziness.

TWEETABLE ABSTRACT

Review finds paroxetine effective for menopausal symptoms with some side effects: evidence strength moderate.

Efficacy and Tolerability of Generic Mirtazapine (Mirtax) for Major Depressive Disorder: Multicenter, Open-label, Uncontrolled, Prospective Study

OBJECTIVE

Mirtax is a generic mirtazapine widely used since 2003. We conducted an open-label, uncontrolled 6-week study to evaluate the efficacy and safety of Mirtax for major depressive disorder (MDD).

METHODS

Ninety three MDD patients with the diagnosis of MDD and 17-item Hamilton Depression Rating Scale (HDRS) score ≥14 were recruited. The HDRS, Montgomery-Åsberg Depression Rating Scale (MADRS), and the Clinical Global Impressions-Severity Scale (CGI-S) were administered at baseline, 1, 2, 4 and 6 weeks. Response (≥50% decrease in the HDRS or MADRS score), remission (absolute HDRS score ≤7 or MADRS score ≤10) and CGI-I score ≤2 were also calculated. Adverse event (AE) frequency and severity, weight, blood pressure, and pulse rate were checked to assess safety.

RESULTS

The starting dosage was 11.5±6.4 mg/day, and the maintenance dosage was 23.1±9.4 mg/day. During 6 weeks, HDRS, MADRS and CGI-S scores decreased from 25.1±5.6 to 11.9±8.6 (mean change -13.1±8.3, p<0.001), from 30.2±6.3 to 13.73±10.40 (mean change -16.5±9.8, p<0.001), and from 5.0±0.8 to 2.5±1.3 (mean change -2.5±1.3, p<0.001), respectively. The percentages of responders, remitters by HDRS and patients with a CGI-I score ≤2 were 64.6%, 35.4% and 52.7%, respectively. Significant decreases in HDRS, MADRS and CGI-S scores were confirmed at week 1. The total rate of AEs was 32.3%; the most frequently reported AEs were sedation (4.3%) and constipation (4.3%). Weight was increased from 58.8±10.6 to 60.3±9.3 kg (mean change 0.7±1.7 kg, p=0.004).

CONCLUSION

This study, as the first clinical trial of generic mirtazapine, demonstrated the efficacy and tolerability of Mirtax for MDD using a single treatment design.

Pharmacokinetic properties of once-daily oral low-dose mesylate salt of paroxetine (LDMP 7.5 mg) following single and multiple doses in healthy postmenopausal women

BACKGROUND

Low-dose mesylate salt of paroxetine (LDMP 7.5 mg) is being investigated for the treatment of vasomotor symptoms associated with menopause.

OBJECTIVE

This Phase I, open-label, single- and multiple-dose study evaluated the pharmacokinetic properties, safety and tolerability of LDMP in postmenopausal, nonsmoking women aged ≥40 years.

METHODS

After a 3-week screening period, subjects received LDMP 7.5-mg capsules as a single dose on day 1 and then as multiple doses (once daily for 14 days) on Days 6-19. Blood samples were collected predose and up to 120 hours postdose on day 1 (single-dose pharmacokinetic profile), at predose (after 12 doses) on day 18, and at predose and up to 24 hours postdose on day 19 (multiple-dose pharmacokinetic profile). Capsules were taken with 240 mL of water while subjects were fasted. Safety was evaluated throughout the study.

RESULTS

Twenty-four women (mean age, 56 years) completed the study. On day 1, median Tmax was ~6 hours, and mean t1/2 was 17.30 hours. Mean plasma concentrations attained predose on days 18 and 19 (days 13 and 14 of multiple dosing) and at 24 hours postdose (day 20) were similar, suggesting that steady state was achieved by day 13 of multiple dosing after 12 daily doses. Mean AUC0-24 h at steady state (day 14 of multiple dosing) was ~3-fold greater than AUC0-∞ on day 1, indicating nonlinear pharmacokinetics. Mean Cmax on day 14 of multiple dosing was ~5-fold greater than that attained on day 1, and the accumulation index (AUCday 19/AUCday 1) at steady state was 9.71. Fluctuation index (calculated as [(Cmax - Cmin)/Cavg ss] × 100) was 75.8%. Most subjects (23/24 [95.8%]) experienced at least 1 treatment-emergent adverse event (AE); however, most AEs (67 events in 22/24 subjects [91.7%]) were mild, and the remainder were moderate. Seventeen subjects experienced 33 AEs that were deemed possibly or probably related to LDMP. No serious AEs were reported, and no clinically meaningful changes in laboratory values, vital signs, or ECGs were observed.

CONCLUSIONS

On multiple dosing, LDMP exhibited nonlinear pharmacokinetics and was well tolerated in these healthy postmenopausal women; the extent of accumulation was consistent with data from the published literature.

Paroxetine for the treatment of depression: a critical update

INTRODUCTION

A growth in the market for antidepressants, paired with an ever-increasing population affected from depressive disorder, requires a critical re-evaluation of most prescribed antidepressants, in order to provide up-to-date practical prescribing information for clinicians. Paroxetine represents a widely prescribed and reliable antidepressant for the expert clinician, but the latest data do not rank it amongst the most effective and tolerable newer antidepressants.

AREAS COVERED

This paper reviews latest data on paroxetine and investigates its clinical efficacy and safety in different groups of patients.

EXPERT OPINION

In previous subanalysis and metaregression analysis, paroxetine failed to show clear differences in terms of efficacy across clinical subgroups. Thus, nowadays the pharmacokinetic and pharmacodynamic properties of the molecule are fundamental to guiding its prescription, both for efficacy and tolerability issues, for example, it can have a high impact on sexual function and weight should also be considered at the beginning of treatment. Since prescription is still based mainly on its side-effect profile, newer and more accurate directions for an individualized prescription are needed.