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Background: Posttraumatic stress disorder (PTSD) is often a chronic, disabling illness for which antidepressant medications (ie, SSRI) are considered the primary psychopharmacological treatment. However, many patients remain refractory to antidepressants alone or in combination with psychotherapy. Safe and effective treatments for individuals with refractory PTSD are needed. This study aimed to examine ziprasidone augmentation of SSRI treatment of PTSD., Methods: This was a 2-phase study. In phase 1, subjects were treated with paroxetine or sertraline for 8 weeks. Individuals refractory to the SSRI treatment then entered into phase II of the study and were randomized, in a double-blind fashion, to 8 weeks of treatment with either ziprasidone or placebo. The primary outcome measure was change in Clinician Administered PTSD Scale total scores with the intent-to-treat sample. Secondary outcome measures included Positive and Negative Syndrome Scale scores, measures of depression and anxiety, and safety measures., Results: No significant differences were observed on the Clinician Administered PTSD Scale, Positive and Negative Syndrome Scale, or other outcome measures between ziprasidone and placebo groups. No significant differences were observed for safety measures including metabolic profiles, extrapyramidal symptoms/movement disorder rating scales, nor study dropout., Conclusions: Although no significant differences were noted in efficacy or safety measures between ziprasidone and placebo in this pilot study, the small sample size prevents definitive conclusions.

Background: Late-life depression, often in association with anxiety, affects approximately 15% of individuals older than 65 years. Selective serotonin reuptake inhibitors are the first-line treatment but could be responsible of an early exacerbation of anxiety, possibly reduced by a very gradual titration of drugs. The main aim of this study is to compare gradual and rapid (standard) titration of paroxetine in an elderly population., Methods: In a naturalistic setting, 50 elderly (≥60 years old) outpatients with unipolar mood disorder or anxiety disorder were naturalistically assigned to abrupt initiation of 10 mg of paroxetine or to a gradual increase with 2.5 mg on alternate days up to 10 mg in 7 days. Then dosage could be maintained at 10 mg or increased according to clinical response. Primary outcome was efficacy as assessed by the Hamilton Depression Rating Scale (HAM-D) 21, HAM-D symptom subscales (core, psychic anxiety, somatic anxiety cluster), and Hamilton Anxiety Rating Scale changes. Secondary outcome was evaluation of overall dropouts at eighth week and evaluation of most common adverse effects through the global judgment of the Dosage Record and Treatment Emergent Symptom Scale. All data were recorded weekly for the first 8 weeks of treatment (with 1 more evaluation after 3 days from the baseline)., Results: Samples were comparable at baseline, with patients in gradual titration showing a higher level of psychic anxiety. During the first 3 days of treatment, a significant worsening in psychic anxiety was observed in patients treated abruptly with 10 mg of paroxetine (difference in HAM-D psychic anxiety subscale from baseline: 110.61% vs 89.38% with rapid and slow titration, respectively; t test P = 0.03). Overall, a significantly greater improvement in depressive and anxious symptoms favored gradual titration (HAM-D core cluster and HAM-D psychic anxiety cluster, respectively, P = 0.014 and P < 0.001, also when controlling for confounders). At the eighth week, significant higher dropouts in patients administered with abrupt dosage was observed (12.00% vs 40.91%, P = 0.02, respectively for slow and rapid titration)., Conclusions: Our results suggest that a gradual titration of paroxetine could avoid the initial treatment anxiety worsening and dropout at the beginning of the treatment.

This long-term extension of an 8-week randomized, naturalistic study in patients with panic disorder with or without agoraphobia compared the efficacy and safety of clonazepam (n = 47) and paroxetine (n = 37) over a 3-year total treatment duration. Target doses for all patients were 2 mg/d clonazepam and 40 mg/d paroxetine (both taken at bedtime). This study reports data from the long-term period (34 months), following the initial 8-week treatment phase. Thus, total treatment duration was 36 months. Patients with a good primary outcome during acute treatment continued monotherapy with clonazepam or paroxetine, but patients with partial primary treatment success were switched to the combination therapy. At initiation of the long-term study, the mean doses of clonazepam and paroxetine were 1.9 (SD, 0.30) and 38.4 (SD, 3.74) mg/d, respectively. These doses were maintained until month 36 (clonazepam 1.9 [SD, 0.29] mg/d and paroxetine 38.2 [SD, 3.87] mg/d). Long-term treatment with clonazepam led to a small but significantly better Clinical Global Impression (CGI)-Improvement rating than treatment with paroxetine (mean difference: CGI-Severity scale -3.48 vs -3.24, respectively, P = 0.02; CGI-Improvement scale 1.06 vs 1.11, respectively, P = 0.04). Both treatments similarly reduced the number of panic attacks and severity of anxiety. Patients treated with clonazepam had significantly fewer adverse events than those treated with paroxetine (28.9% vs 70.6%, P < 0.001). The efficacy of clonazepam and paroxetine for the treatment of panic disorder was maintained over the long-term course. There was a significant advantage with clonazepam over paroxetine with respect to the frequency and nature of adverse events.

To compare the efficacy and safety of augmenting paroxetine with risperidone, buspirone, valproate, trazodone, or thyroid hormone in patients with treatment-resistant depression (TRD), 225 patients with retrospectively and/or prospectively identified stage II TRD were randomly assigned to receive an 8-week treatment of paroxetine 20 mg/d augmented with risperidone 2 mg/d (n = 45), sodium valproate 600 mg/d (n = 39), buspirone 30 mg/d (n = 46), trazodone 100 mg/d (n = 47), or thyroid hormone 80 mg/d (n = 48). The primary outcome was the remission rate defined as the 17-item Hamilton Rating Scale for Depression score of 7 or less at the end of study. Secondary outcomes included remission rate based on the Self-rating Depression Scale score of 50 or less at the end of study, response rate based on 17-item Hamilton Rating Scale for Depression total score of 50% improvement or greater from baseline, and the change in scores of Clinical Global Impression-Improvement scale, the Short Form 36 Health Survey, and the Life Satisfaction Rating Scale. The remission rates were 26.7% for risperidone, 48.7% for valproate, 32.6% for buspirone, 42.6% for trazodone, and 37.5% for thyroid hormone. There was no statistical significance among treatment arms in remission rates, secondary outcome measures, and adverse events. Risperidone, valproate, buspirone, trazodone, or thyroid hormone augmentation to paroxetine 20 mg/d was effective and well tolerated in Chinese patients with TRD. Large-sample studies are warranted to support or refute these findings.

This randomized, placebo-controlled, double-blind study was the first to evaluate the antidepressant efficacy, safety, and tolerability of an NR2B subunit-selective N-methyl-D-aspartate receptor antagonist, CP-101,606. Subjects had major depression, according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and a history of treatment refractoriness to least 1 adequate trial of a selective serotonin reuptake inhibitor. The study had 2 treatment periods. In period 1, subjects first received a 6-week open-label trial of paroxetine and a single-blind, intravenous placebo infusion. Period 1 nonresponders (n = 30) then received a randomized double-blind single infusion of CP-101,606 or placebo plus continued treatment with paroxetine for up to an additional 4 weeks (period 2). Depression severity was assessed using the Montgomery-Asberg Depression Rating Scale and 17-item Hamilton Depression Rating Scale. On the prespecified main outcome measure (change from baseline in the Montgomery-Asberg Depression Rating Scale total score at day 5 of period 2), CP-101,606 produced a greater decrease than did placebo (mean difference, 8.6; 80% confidence interval, -12.3 to -4.5) (P < 0.10). Hamilton Depression Rating Scale response rate was 60% for CP-101,606 versus 20% for placebo. Seventy-eight percent of CP-101,606-treated responders maintained response status for at least 1 week after the infusion. CP-101,606 was safe, generally well tolerated, and capable of producing an antidepressant response without also producing a dissociative reaction. Antagonism of the NR2B subtype of the N-methyl-D-aspartate receptor may be a fruitful target for the development of a new antidepressant with more robust effects and a faster onset compared with those currently available and capable of working when existing antidepressants do not.

Rationale: Impaired psychomotor function has been shown to be associated with clinical and functional outcome in schizophrenia. However, few studies have investigated the short-term effects of antipsychotics on the cognitive and psychomotor functions of this patient group. Because many confounding factors tend to influence the test results in patient research, this study investigates the drugs' effects in healthy volunteers., Objectives: The short-term effects of haloperidol (2.5 mg), olanzapine (10 mg), and paroxetine (20 mg) on psychomotor function in 15 healthy volunteers are compared with placebo and each other., Methods: In a crossover design, the subjects completed a battery of psychomotor tasks assessing psychomotor speed, sensorimotor accuracy, visuospatial monitoring, and speed of information processing. In addition, peak velocity of saccadic eye movements and subscales of the visual analog scales were analyzed as the objective and subjective measures for sedation, respectively. Finally, the verbal memory test was used to assess the drugs' effects on memory., Results: Apart from affecting the pursuit task where visuospatial monitoring, sensorimotor speed, and sensorimotor accuracy are measured simultaneously, haloperidol has been proven to be not associated with sedative nor with impairing effects on psychomotor function or verbal memory. In contrast, olanzapine had significant sedative effects. Moreover, the subjects displayed a significant impairment on all measures of psychomotor function and verbal memory, which was not attributable to the drug's sedative effects. After administration of paroxetine, no effects were found, with the exception of a single improvement in eye movement velocity., Conclusions: Short-term administration of olanzapine, and not of haloperidol, impedes several aspects of psychomotor function and verbal memory in healthy volunteers.

Unlabelled: Symptoms of premenstrual dysphoric disorder (PMDD) respond to serotonin reuptake inhibitors when treatment is limited to 14 days of the menstrual cycle. Many women have less than a week of symptoms, and shorter treatment intervals would further reduce medication exposure and costs., Methods: Twenty women with PMDD were randomly assigned to either paroxetine CR or placebo for 1 cycle and crossed over to the other condition for a second cycle. Subjects initiated treatment when premenstrual symptoms began and stopped within 3 days of beginning menses., Results: Women took capsules for an average of 9 days (range, 3-15 days), including the first few days of menses. Moderate "PMDD level" symptoms occurred in 1 subject (6%) for 2 days and 4 subjects (24%) for 1 day before starting paroxetine or placebo. Daily Record of Severity of Problems scores were lower in the paroxetine group compared with the placebo group, although the differences were not statistically significant. However, the mean on-treatment Inventory of Depressive Symptomatology (clinician-rated) score for the paroxetine group was 17.9 +/- 8.3 compared with 31.5 +/- 11.2 in the placebo group (adjusted mean difference = 13.6, P = 0.009). Response (Clinical Global Impressions Scale score of 1 or 2) occurred in 70% of subjects randomized to paroxetine CR and 10% of those assigned to placebo (chi2(1) = 7.5, P = 0.006). Discontinuation symptoms did not differ in the groups., Conclusion: These data suggest the need to further evaluate symptom-onset treatment in a larger randomized clinical trial.

Augmentation with paroxetine (10-40 mg/d) for antipsychotic treatment may improve the negative symptoms in schizophrenic patients but involves a risk of drug-drug interaction. We studied the effects of paroxetine on plasma concentrations of risperidone and 9-hydroxyrisperidone and their clinical symptoms in risperidone-treated patients. Twelve schizophrenic inpatients with prevailingly negative symptoms receiving risperidone 4 mg/d were, in addition, treated with incremental doses of paroxetine for 12 weeks (10, 20, and 40 mg/d for 4 weeks each). Plasma concentrations of risperidone and 9-hydroxyrisperidone were quantified with liquid chromatography-mass spectrometry mass-mass spectrometry together with clinical assessments before and after each phase of the 3 paroxetine doses. Risperidone concentrations during coadministration of paroxetine 10, 20, and 40 mg/d were 3.8-fold (95% confidence interval, 3.2-5.8, P < 0.01), 7.1-fold (95% confidence interval, 5.3-16.5, P < 0.01), and 9.7-fold (95% confidence interval, 7.8-22.5, P < 0.01) higher than that before paroxetine coadministration, respectively. Active moiety (risperidone plus 9-hydroxyrisperidone) concentration was not increased during the paroxetine 10 mg/d (1.3-fold, not significant) or 20 mg/d (1.6-fold, not significant), but were significantly increased by 1.8-fold (95% confidence interval, 1.4-2.7, P < 0.05) during the paroxetine 40 mg/d. Significant improvement in negative symptoms was observed from 10 to 40 mg/d of paroxetine, whereas scores in extrapyramidal side effects during 20 and 40 mg/d of paroxetine were significantly higher than baseline score. This study indicates that paroxetine increases plasma risperidone concentration and active moiety concentration in a dose-dependent manner. Low-dose coadministration of paroxetine with risperidone may be safe and effective in the treatment of schizophrenic patients with negative symptoms.

This study compared the stabilized duloxetine dose through approximately 12 weeks of treatment in patients initiating duloxetine therapy with that in patients switching to duloxetine from selective serotonin reuptake inhibitors or venlafaxine. All patients met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for major depressive disorder. Patients (n = 112) exhibiting suboptimal response or poor tolerability to their current antidepressant medication (citalopram, escitalopram, fluvoxamine, paroxetine, sertraline, or venlafaxine) were switched to duloxetine 60 mg once daily (QD) without intermediate tapering or titration ("switching" group). A comparator group (n = 137), comprising patients not currently receiving antidepressant medication, was randomized to receive duloxetine 30 or 60 mg QD ("initiating" group). At the end of week 1, patients receiving 30 mg QD had their dose increased to 60 mg QD. During the remainder of the study, each patient's duloxetine dose could be titrated on the basis of degree of response within a range from 60 to 120 mg QD, with 90 mg QD as an intermediate dose. At the study end point, approximately one third of the patients in each treatment group were stabilized at each of the 3 studied duloxetine doses (60, 90, and 120 mg QD), and the distribution of stabilized doses among patients initiating duloxetine therapy did not differ significantly from that observed in patients switching to duloxetine. The efficacy of duloxetine in patients switching from selective serotonin reuptake inhibitor/venlafaxine did not differ significantly from that observed in untreated patients initiating duloxetine therapy (baseline-to-end point mean changes: 17-Item Hamilton Rating Scale for Depression total score, -13.1 vs. -13.5; Hamilton Rating Scale for Anxiety, -10.6 vs. -10.3; and Clinical Global Impression of Severity, -2.22 vs. -2.38, respectively). The rate of discontinuation caused by adverse events among patients switched to duloxetine was significantly lower than that in patients initiating duloxetine therapy (6.3% vs. 16.1%, P = 0.018). Treatment-emergent adverse events occurring in more than 10% of patients in both treatment groups were nausea, headache, dry mouth, insomnia, diarrhea, and constipation. In the first week of therapy, patients switched to duloxetine reported significantly lower rates of headache and fatigue compared with patients initiating duloxetine. Thus, the efficacy of duloxetine in switched patients was comparable to that observed in patients initiating duloxetine therapy. Immediate switching from a selective serotonin reuptake inhibitor or venlafaxine to duloxetine (60 mg QD) was well tolerated.

Although serotonin reuptake inhibitors are recommended as first-line agents for major depressive disorder, delayed onset of action is problematic, and faster effective treatment is needed. Sulpiride, a dopamine-mediated agent, has been reported to show faster antidepressant efficacy, and we examined the efficacy of adjunctive sulpiride in combination with paroxetine (PAX), compared with PAX alone, to clarify whether the combined treatment exerts faster effect. Forty-one major depressive disorder patients were enrolled in this 12-week open-label trial and were randomly assigned to a PAX (10-40 mg/d) or a PAX (10-40 mg/d) plus sulpiride (100 mg/d) group. Assessments included the Montgomery-Asberg Depression Rating Scale, the 17-item Hamilton Rating Scale for Depression, and the Zung Self-rating Depression Scale on an intent-to-treat basis, and safety was also monitored. Thirty-three patients completed the study. Both PAX + sulpiride and PAX treatments showed a mean reduction in the total Montgomery-Asberg Depression Rating Scale score of 34.4 to 5.6 and 32.2 to 10.4, respectively (P < 0.001). The combined treatment group had a significantly superior outcome in terms of the change in the total Montgomery-Asberg Depression Rating Scale, Hamilton Rating Scale for Depression, and Zung Self-rating Depression Scale scores between week 1 and the study end point (P < 0.05). Median times to response among responders alone for the combined treatment and monotherapy were 2 and 6 weeks, respectively. Both treatments were well tolerated, with no clinically significant differences in safety measures except for an elevation of prolactin in the combined treatment group. The combination treatment may be a safe and effective strategy for accelerating antidepressant response.

Depressed patients may exhibit reduced heart rate variability (HRV), and antidepressants which block norepinephrine uptake may also lower HRV. This study compared paroxetine (PAR) and venlafaxine XR (VEN-XR) on HRV. Outpatients were randomly assigned to double-blind treatment with PAR up to 40 mg or VEN-XR up to 225 mg daily. HRV measures of parasympathetic control consisted of change in R-R interval during forced 10-second breaths and respiratory sinus arrhythmia (RSA) during paced breathing. Ex vivo estimates of serotonin and norepinephrine transporter occupancy were obtained before and after treatment, as were measures of depression, anxiety, and resilience. Plasma drug concentrations were measured at end point. Forty-nine patients entered treatment; 44 of whom were evaluable (n = 22 per group). Significant within-group reductions were noted in R-R interval variation and in RSA after VEN-XR only. Between-group analyses showed significant group-by-time interaction, with greater reduction in R-R interval variation and in RSA for VEN-XR compared with PAR. Improvement in resiliency correlated significantly with norepinephrine transporter occupancy for VEN-XR. Further comparisons of selective serotonin reuptake inhibitor and serotonin and norepinephrine reuptake inhibitor drugs on HRV are warranted.

This investigation aimed to provide evidence on the lack of pharmacokinetic interaction of paroxetine (20 mg/d) and alprazolam (1 mg/d) in combined therapy. In addition, the central effects of both drugs when administered alone and in combination were assessed to rule out any relevant synergistic depressant central effect. Twenty-five healthy young adult volunteers participated in a double-blind, double-dummy, placebo-controlled, repeated dose (15 days), 4-period crossover study. Each subject received each of 4 treatment sequences (ie, paroxetine-alprazolam placebo, alprazolam-paroxetine placebo, paroxetine-alprazolam, and paroxetine placebo-alprazolam placebo) in randomized order. The ratios for area under the curve within a dosing interval and maximum plasma concentration of the paroxetine plus alprazolam sequence to single agent paroxetine were 1.07 (90% confidence interval = 0.99 to 1.16) and 1.05 (90% confidence interval = 0.97 to 1.13), respectively, with no statistically significant differences between the 2 treatments. Similarly, for alprazolam, ratios for the combined to the single treatment sequence were 0.99 (90% confidence interval = 0.93 to 1.05) and 1.00 (90% confidence interval = 0.94 to 1.07) for area under the curve within a dosing interval and maximum plasma concentration, respectively, showing no evidence for interaction. Comparative pharmacodynamics on the combination was assessed using 6 Psychomotor Performance Tests and 5 Visual Analogue Scales focused on mood variables. Alprazolam and paroxetine plus alprazolam induced similar and significant performance impairment and sedation after both single and repeated dose administration, being less evident on day 15. After dosing, paroxetine plus alprazolam showed a lower recovery pattern than alprazolam alone, especially on day 15. No treatment sequence showed cumulative effects after repeated dose administration. Psychomotor Performance Tests and Visual Analogue Scales data suggested lack of pharmacodynamic interactions. Accordingly, study results showed no evidence for pharmacologic interactions between paroxetine and alprazolam at steady state. The most commonly reported adverse event was drowsiness, with a higher incidence under both single and combined alprazolam treatments.

Steady-state blood concentrations of (R)- methadone (i.e., the active form), (S)-methadone, and (R,S)-methadone were measured before and after introduction of paroxetine 20 mg/day during a mean period of 12 days in 10 addict patients in methadone maintenance treatment. Eight patients were genotyped as CYP2D6 homozygous extensive metabolizers (EMs) and two patients as poor metabolizers (PMs). Paroxetine significantly increased concentrations of both enantiomers of methadone in the whole group (mean increase for (R)-methadone +/- SD, 26 +/- 32%; range, -14% to +83%, p = 0.032; for (S)-methadone, 49 +/- 51%; range, -29% to +137%, p = 0.028; for (R,S)-methadone, 35 +/- 41%; range, -20% to +112%, p = 0.032) and in the group of eight EMs (mean increase, 32%, p = 0.036; 53%, p = 0.028; and 42%, p = 0.036, for (R)-methadone, (S)-methadone, and (R,S)-methadone, respectively). On the other hand, in the two PMs, (S)-methadone but not (R)-methadone concentrations were increased by paroxetine (mean increases of 36% and 3%, respectively). Paroxetine is a strong CYP2D6 inhibitor, and these results confirm previous studies showing an involvement of CYP2D6 in methadone metabolism with a stereoselectivity toward the (R)-enantiomer. Because paroxetine is a mild inhibitor of CYP1A2, CYP2C9, CYP2C19, and CYP3A4, increase of (S)-methadone concentrations in both EMs and PMs could be mediated by inhibition of any of these isozymes.

This study investigated the effects of antidepressant treatment on platelet activation in depressed patients with ischemic heart disease (IHD). Plasma levels of platelet alpha-granule release products beta-thromboglobulin (BTG) and platelet factor 4 (PF4) were measured in 17 depressed patients with IHD who were treated in a 6-week, double-blind trial with either paroxetine (10 patients) or nortriptyline (7 patients). Baseline measurements of BTG and PF4 were significantly elevated in both drug treatment groups before the initiation of antidepressant therapy compared with those of healthy control subjects. In the paroxetine group, mean PF4 and BTG levels significantly decreased from these elevated baseline values within 1 week of treatment and remained low at 3- and 6-week measurements. In contrast, the nortriptyline group did not exhibit a significant decrease in PF4 or BTG plasma levels after 1, 3, or 6 weeks of treatment. Therefore, platelet activation in depressed patients with IHD seems to be inhibited by the selective serotonin reuptake inhibitor paroxetine. The effect of paroxetine on PF4 and BTG plasma levels suggests that it may reduce platelet aggregation in vivo and may positively impact IHD-related mortality in this population.

The aim of this study was to evaluate the CYP2D6 inhibitory effects of four selective rerotonin re-uptake inhibitors (SSRIs). Thirty-one healthy subjects were phenotyped as extensive metabolizers using the dextromethorphan/dextrorphan (DM/DX) urinary ratio as a marker for CYP2D6 activity before and after 8 days of administration of fluoxetine 60 mg (loading dose strategy), fluvoxamine 100 mg, paroxetine 20 mg, or sertraline 100 mg in a parallel-group design. Statistical analysis was performed on log-transformed DM/DX ratios because of variability within and between treatment groups. DM/DX ratios before (DM/DX(BL)) and after (DM/DX(SSRI)) were compared within and between the four SSRI groups. DM/DX(BL) ratios were not significantly different between the four SSRI treatment groups. Comparing within groups, significant differences between DM/DX(BL) and DM/DX(SSRI) were found for the fluoxetine (p < 0.001; ratio values, 0.020 vs. 0.364) and paroxetine (p = 0.0005, ratio values 0.029 vs. 1.085) but not for the fluvoxamine or sertraline groups. Comparing between groups, significant differences in DM/DX(SSRI) ratios were found for fluoxetine versus sertraline (p = 0.0019, DM/DX = 0.364 vs. 0.057), fluoxetine versus fluvoxamine (p < 0.0001, DM/DX = 0.364 vs. 0.019), paroxetine versus sertraline (p = 0.0026, DM/DX = 1.085 vs. 0.057), and paroxetine versus fluvoxamine (p < 0.0001, DM/DX = 1.085 vs. 0.019). No significant differences were noted between the two potent CYP2D6 inhibitors, fluoxetine and paroxetine, or the two weakest inhibitors, fluvoxamine and sertraline. Five subjects in the fluoxetine and four subjects in the paroxetine groups changed to poor metabolizer phenotype (DM/DX > or = 0.3) after treatment. Although CYP2D6 inhibitory effects of fluvoxamine and sertraline did not yield significant differences from baseline, some subjects exhibited DM/DX ratio increases of 150 to 200%. One paroxetine-treated subject did not exhibit any CYP2D6 inhibition. SSRI dose and plasma concentration may be correlated with the extent of CYP2D6 inhibition and should be further investigated.

In vitro studies have shown that fluoxetine and paroxetine are more potent inhibitors of cytochrome CYP2D6 than sertraline. The pharmacokinetics of desipramine when coadministered with the selective serotonin reuptake inhibitors (SSRIs) paroxetine and sertraline were studied in 24 healthy male volunteers (CYP2D6 extensive metabolizers). Desipramine (50 mg/day) was administered for 23 days in each phase of the crossover study with a 7-day drug-free period between phases. In addition, subjects were randomly assigned to receive concomitant paroxetine (20 mg/day on days 8 through 17 followed by 30 mg/day on days 18 through 20) or sertraline (50 mg/day on days 8 through 17 and 100 mg/day on days 18 through 20). SSRI treatments were switched between phases. After 10 days of coadministration at the lower dose, mean desipramine maximum concentration in plasma (Cmax) relative to baseline increased from 37.8 to 173 ng/mL (+358%) with paroxetine versus from 36.1 to 51.9 ng/mL (+44%) with sertraline; the mean desipramine 24-hour area under the concentration-time curve (AUC[24]) increased from 634 to 3,305 ng x h/mL (+421%) with paroxetine versus from 611 to 838 ng x h/mL (+37%) with sertraline; and the mean desipramine trough value (C0) increased from 18.5 to 113 ng/mL (+511%) with paroxetine versus from 18.3 to 21.8 ng/mL (+19%) with sertraline (all increases, p < 0.001). An approximately 10-fold increase in the Cmax and AUC(24) of paroxetine and an approximately 2-fold increase in these parameters for sertraline occurred simultaneously with the desipramine concentration changes. Thus, when coadministered with 50 mg/day desipramine, sertraline had significantly less pharmacokinetic interaction than paroxetine with desipramine at the recommended starting dosages of 50 mg/day and 20 mg/day, respectively.

A total of 32 unmedicated patients with episodes of major depression (DSM-III-R) and 32 normal control subjects matched for age and sex were tested for heart rate variability (R-R variation) while resting and during deep breathing. Compared with the group of healthy subjects, the depressed patients showed no abnormalities before therapy. The patients were randomly allocated for treatment with 150 mg of amitriptyline per day (N = 8), 150 mg of doxepin per day (N = 8), 150 mg of fluvoxamine per day (N = 8), and 20 mg of paroxetine per day (N = 8). During treatment with either amitriptyline or doxepin, the coefficients of variation at rest and during deep breathing, which are largely independent of heart rate, had significantly decreased after 14 days (p = 0.012), whereas patients treated with fluvoxamine or paroxetine showed no significant changes of heart rate variability parameters after 14 days. The implications of these findings are discussed.