Pharmacokinetic and pharmacodynamic characteristics of a controlled-release formulation of trazodone versus the conventional formulation in healthy volunteers

Role of trazodone in treatment of major depressive disorder: an update

Major depressive disorder (MDD) is the most common mood disorder and a leading cause of disability worldwide. Trazodone, a triazolopyridine serotonin receptor antagonist and reuptake inhibitor (SARI) antidepressant approved for major depressive disorder (MDD) in adults, has established efficacy that is comparable to other available antidepressants, and is effective for a range of depression symptoms, including insomnia, which is one of the most common and bothersome symptoms of depression. Also, trazodone's pharmacodynamic properties allow it to avoid the side effects of insomnia, anxiety and sexual dysfunction often associated with selective serotonin reuptake inhibitor antidepressants. In this narrative review, we have summarized recent clinical trials and real-world data on trazodone, including the recently introduced once-daily formulation, which has single dose pharmacokinetic properties that maintain effective blood trazodone levels for 24 h, while avoiding concentration peaks associated with side effects. This, combined with a low incidence of weight gain, and sexual dysfunction, may improve adherence to treatment. The most common adverse effects of trazodone are somnolence, headache, dizziness and xerostomia. It has minimal anticholinergic activity but may be associated infrequently with orthostatic hypotension (especially in patients with cardiovascular disease or older adults), QT interval prolongation, cardiac arrhythmias, and rare episodes of priapism. The low liability for activating side effects, the efficacy on symptoms such as insomnia and psychomotor agitation and the rapid onset of action make it useful for many depressed patients, both in monotherapy at nominal dosages of 150-300 mg/day, and in combination with other antidepressants at lower dosages.

Early response to trazodone once-a-day in major depressive disorder: review of the clinical data and putative mechanism for faster onset of action

BACKGROUND

Most antidepressants have a delayed onset of action and must be administered for several weeks to generate therapeutic effects. Trazodone is a serotonin antagonist and reuptake inhibitor approved for the treatment of major depressive disorder. The once-a-day (OAD) formulation of trazodone has an improved tolerability profile compared to its conventional formulations. In this study, we systematically reviewed the evidence available for the antidepressant efficacy and early improvement in depressive symptoms with trazodone OAD treatment.

METHOD

We conducted a PubMed database search for randomized controlled trials published from 2005 to 2020.

RESULTS

Two studies, a placebo-controlled and an active-comparator (venlafaxine extended-release or XR) study were found. Both the studies demonstrated that trazodone exhibits antidepressant activity at a starting dose of 150 mg/day and results in statistically significant greater reduction in Hamilton Depression Rating Scale (HAM-D17) scores within 1 week of starting treatment compared to placebo or venlafaxine XR (P < .05). Trazodone also resulted in significant early improvement in the HAM-D17 sleep disturbance factor compared to placebo or venlafaxine XR at day 7 (P < .05). This clinical effect is supported by in vitro proprietary data for the affinity of trazodone for different target receptors. Activity at these receptors may underlie trazodone's fast antidepressant action.

CONCLUSIONS

Trazodone, if properly dosed, can be an effective antidepressant with early onset of action and good tolerability. Future studies designed to specifically evaluate onset and timing of improvement of depressive symptoms remain necessary to confirm and extend these results.

Dose proportionality of once-daily trazodone extended-release caplets under fasting conditions

An extended-release trazodone HCl formulation, Trazodone Contramid OAD (TzCOAD), was developed as scored 150-mg and 300-mg caplets for once-daily administration. Dose proportionality of intact and bisected caplets (dose range, 75-375 mg) was evaluated in a single-dose, randomized, 5-way crossover study. Plasma trazodone and m-chlorophenylpiperazine (mCPP) levels were determined using a validated liquid chromatography-tandem mass spectroscopy method. Dose proportionality was assessed based on confidence intervals for logarithmically transformed, dose-normalized maximum plasma concentration (C(max)), area under the plasma concentration versus time data pairs (AUC(0-t)), and area under the curve from time 0 to infinity (AUC(0-∞)) in relation to the acceptance range of 80% to 125% (bioequivalence approach). The power method, combined with confidence interval criteria, was also used to assess proportionality. The conclusion of dose proportionality was generally supported using the bioequivalence approach. Based on the power model, values of the slope and corresponding 90% confidence interval for trazodone C(max), AUC(0-t), and AUC(0-∞) were 0.948 (0.899-0.997), 0.920 (0.875-0.964), and 0.913 (0.867-0.958), respectively. All were within the acceptance interval (0.861-1.139). Results for mCPP also fell within the acceptance interval. TzCOAD exhibits linear pharmacokinetics over doses ranging from 75 to 375 mg and maintains its controlled-release properties when the caplets are bisected along the score line.

Clinical and polysomnographic effects of trazodone CR in chronic insomnia associated with dysthymia

Six middle aged subjects complaining of chronic insomnia associated with dysthymia were investigated in a 2-month single blind study: a 7-day placebo treatment period, followed by a 6-week phase with increasing doses of trazodone controlled release (CR) formulation (50 mg through days 8-10; 75 mg through days 11-13; 150 mg through days 14-49) and then a final 7-day withdrawal period under placebo. Medication was always administered at bedtime. Five polysomnographic recordings were accomplished by each subject (sleep 1: under baseline placebo; sleep 2-3-4; under active treatment; sleep 5: after drug discontinuation). A "blind" EEG reader analysed the traditional polysomnographic variables (macrostructure of sleep) and the amount and percentage ratio (CAP rate) of cyclic alternating pattern (CAP), the microstructural parameter that measures the instability of arousal during sleep. Visual analogue scales (VAS) for the evaluation of subjective sleep quality and the Hamilton rating scale for depression (HAM-D) were regularly assessed across the study. Statistical analysis was based on an ANOVA test with repeated measures completed by means of Bonferroni adjusted probabilities. No significant differences emerged from the macrostructural parameters referred to sleep initiation and maintenance, while significant overall modifications emerged from stage 2 (P < 0.0005), slow wave sleep (P < 0.0001), total CAP time (P < 0.0001) and CAP rate (P < 0.0001). Compared to the placebo baseline night, a significant increase of slow wave sleep (+40 min) and significant reductions of stage 2 (-67 min), CAP time (-90 min) and CAP rate (-23%) were already found on day 4 of treatment (sleep 2).(ABSTRACT TRUNCATED AT 250 WORDS)