A double-blind comparison of moclobemide and doxepin in depressed general practice patients

General and comparative efficacy and effectiveness of antidepressants in the acute treatment of depressive disorders: a report by the WPA section of pharmacopsychiatry

Current gold standard approaches to the treatment of depression include pharmacotherapeutic and psychotherapeutic interventions with social support. Due to current controversies concerning the efficacy of antidepressants in randomized controlled trials, the generalizability of study findings to wider clinical practice and the increasing importance of socioeconomic considerations, it seems timely to address the uncertainty of concerned patients and relatives, and their treating psychiatrists and general practitioners. We therefore discuss both the efficacy and clinical effectiveness of antidepressants in the treatment of depressive disorders. We explain and clarify useful measures for assessing clinically meaningful antidepressant treatment effects and the types of studies that are useful for addressing uncertainties. This includes considerations of methodological issues in randomized controlled studies, meta-analyses, and effectiveness studies. Furthermore, we summarize the differential efficacy and effectiveness of antidepressants with distinct pharmacodynamic properties, and differences between studies using antidepressants and/or psychotherapy. We also address the differential effectiveness of antidepressant drugs with differing modes of action and in varying subtypes of depressive disorder. After highlighting the clinical usefulness of treatment algorithms and the divergent biological, psychological, and clinical efforts to predict the effectiveness of antidepressant treatments, we conclude that the spectrum of different antidepressant treatments has broadened over the last few decades. The efficacy and clinical effectiveness of antidepressants is statistically significant, clinically relevant, and proven repeatedly. Further optimization of treatment can be helped by clearly structured treatment algorithms and the implementation of psychotherapeutic interventions. Modern individualized antidepressant treatment is in most cases a well-tolerated and efficacious approach to minimize the negative impact of otherwise potentially devastating and life-threatening outcomes in depressive disorders.

Moclobemide: therapeutic use and clinical studies

Moclobemide is a reversible inhibitor of monoamine-oxidase-A (RIMA) and has been extensively evaluated in the treatment of a wide spectrum of depressive disorders and less extensively studied in anxiety disorders. Nearly all meta-analyses and most comparative studies indicated that in the acute management of depression this drug is more efficacious than placebo and as efficacious as tricyclic (or some heterocyclic) antidepressants or selective serotonin reuptake inhibitors (SSRIs). There is a growing evidence that moclobemide is not inferior to other antidepressants in the treatment of subtypes of depression, such as dysthymia, endogenous (unipolar and bipolar), reactive, atypical, agitated, and retarded depression as with other antidepressants limited evidence suggests that moclobemide has consistent long-term efficacy. However, more controlled studies addressing this issue are needed. For patients with bipolar depression the risk of developing mania seems to be not higher with moclobemide than with other antidepressants. The effective therapeutic dose range for moclobemide in most acute phase trials was 300 to 600 mg, divided in 2 to 3 doses. While one controlled trial and one long-term open-label study found moclobemide to be efficacious in social phobia, three controlled trials subsequently revealed either no effect or less robust effects with the tendency of higher doses (600 - 900 mg/d) to be more efficacious. Two comparative trials demonstrated moclobemide to be as efficacious as fluoxetine or clomipramine in patients suffering from panic disorder. Placebo-controlled trials in this indication are, however, still lacking. A relationship between the plasma concentration of moclobemide and its therapeutic efficacy is not apparent but a positive correlation with adverse events has been found. Dizziness, nausea and insomnia occurred more frequently on moclobemide than on placebo. Due to negligible anticholinergic and antihistaminic actions, moclobemide has been better tolerated than tri- or heterocyclic antidepressants. Gastrointestinal side effects and, especially, sexual dysfunction were much less frequent with moclobemide than with SSRIs. Unlike irreversible MAO-inhibitors, moclobemide has a negligible propensity to induce hypertensive crisis after ingestion of tyramine-rich food ("cheese-reaction"). Therefore, dietary restrictions are not as strict. However, with moclobemide doses above 900 mg/d the risk of interaction with ingested tyramine might become clinically relevant. After multiple dosing the oral bioavailability of moclobemide reaches almost 100%. At therapeutic doses, moclobemide lacks significant negative effects on psychomotor performance, cognitive function or cardiovascular system. Due to the relative freedom from these side effects, moclobemide is particularly attractive in the treatment of elderly patients. Moclobemide is a substrate of CYP2C19. Although it acts as an inhibitor of CYP1A2, CYP2C19, and CYP2D6, relatively few clinically important drug interactions involving moclobemide have been reported. It is relatively safe even in overdose. The drug has a short plasma elimination half-life that allows switching to an alternative agent within 24 h. Since it is well tolerated, therapeutic doses can often be reached rapidly upon onset of treatment. Steady-state plasma levels are reached approximately at one week following dose adjustment. Patients with renal dysfunction require no dose reduction in contrast to patients with severe hepatic impairment. Cases of refractory depression might improve with a combination of moclobemide with other antidepressants, such as clomipramine or a SSRI. Since this combination has rarely been associated with a potentially lethal serotonin syndrome, it requires lower entry doses, a slower dose titration and a more careful monitoring of patients. Combination therapy with moclobemide and other serotonergic agents, or opioids, should be undertaken with caution, although no serious adverse events have been published with therapeutic doses of moclobemide to date. On the basis of animal data the combined use of moclobemide with pethidine or dextropropoxyphene should be avoided. There is no evidence that moclobemide would increase body weight or produce seizures. Some preclinical data suggest that moclobemide may have anticonvulsant property.

Efficacy of newer medications for treating depression in primary care patients

PURPOSE

Several medications have recently been introduced for the treatment of depression. We reviewed the literature to summarize their efficacy in the treatment of depression in adult patients in primary care settings.

METHODS

We searched the literature published from 1980 to January 1998 using the Cochrane Collaboration Depression Anxiety and Neurosis Group's specialized registry of 8,451 clinical trials, references from trials and 46 pertinent meta-analyses, and consultation with experts. We included randomized controlled trials of at least 6 weeks' duration that measured clinical outcomes and compared one of 32 newer medications with another newer antidepressant, an older antidepressant, a placebo, or a psychosocial intervention for the treatment of depressed patients in primary care settings. The primary outcome was response rate, defined as the proportion of patients experiencing a 50% or greater improvement in depressive symptoms.

RESULTS

There were 28 randomized controlled trials involving 5,940 adult primary care patients with major depression, depression requiring treatment, dysthymia, or mixed anxiety depression. Newer agents, including selective serotonin re-uptake inhibitors, serotonin norepinephrine inhibitors, reversible inhibitors of monoamine oxidase, and dopamine antagonists, were usually compared with tricyclic agents. Average response rates were 63% for newer agents, 35% for placebo, and 60% for tricyclic agents. Newer agents were significantly more effective than placebo [risk ratio = 1.6; 95% confidence interval (CI), 1.2 to 2.1), but similar to tricyclic agents (risk ratio = 1.0; 95% CI, 0.9 to 1.1). Response rates were similar in the different types of depressive disorders, except that two small trials in frail older patients showed no significant effects of newer agents compared with placebo. Dropout rates as a result of adverse effects were 8% with newer agents and 13% with tricyclic agents (P <0.05).

CONCLUSIONS

In primary care settings, newer antidepressants are more effective than placebo and have similar efficacy compared with tricyclic agents in the acute treatment of depression. Dropout rates as a result of adverse effects are lower with newer compared with tricyclic agents. Future studies should compare the effectiveness of different therapies among primary care patients with less severe depression and greater medical and psychiatric comorbidity.

Double-blind randomized controlled study of the efficacy and tolerability of two reversible monoamine oxidase A inhibitors, pirlindole and moclobemide, in the treatment of depression

The aim of this double-blind randomized study was to compare the efficacy and the tolerability of moclobemide (300-600 mg daily) and pirlindole (150-300 mg daily), two reversible inhibitors of MAO-A (RIMAs), in the treatment of depression. In total 116 patients were included in the trial, 111 patients (52 patients on pirlindole and 59 patients on moclobemide) were evaluable for efficacy and safety, and 77 patients completed the whole study (42 days of administration). Both treatments produced highly significant improvements in the Hamilton Depression Rating Scale (HDRS) score, the Hamilton Anxiety Rating Scale (HARS) score and the Montgomery-Asberg Rating Scale (MADRS) score from day 7 to day 42. The pattern of development of the three scores in the two groups did not differ significantly. After 42 days of treatment, an improvement of > or = 50% in the HDRS score was noted in 80% and 67% of patients in the pirlindole and moclobemide groups, respectively. A total of 30 (58%) patients on pirlindole and 33 (56%) patients on moclobemide experienced side-effects that were considered to be possibly or probably related to the medication. The differences between the two drugs were non-significant for all types of side-effect, with the exception of dry mouth and tachycardia, which were significantly more frequent with moclobemide.