Amitriptyline and nortriptyline response profiles in unipolar depressed patients

Amitriptyline for depression

BACKGROUND

For many years amitriptyline has been considered one of the reference compounds for the pharmacological treatment of depression. However, new tricyclic drugs, heterocyclic compounds and selective serotonin reuptake inhibitors have been introduced on the market with the claim of a more favourable tolerability/efficacy profile.

OBJECTIVES

The aim of the present systematic review was to investigate the tolerability and efficacy of amitriptyline in comparison with the other tricyclic/heterocyclic antidepressants and with the selective serotonin reuptake inhibitors.

SEARCH STRATEGY

The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR-Studies) was searched on 28-11-2005. Reference lists of all included studies were checked.

SELECTION CRITERIA

Only randomised controlled trials were included. Study participants were of either sex and any age with a primary diagnosis of depression. Included trials compared amitriptyline with another tricyclic/heterocyclic antidepressant or with one of the selective serotonin reuptake inhibitors.

DATA COLLECTION AND ANALYSIS

Data were extracted using a standardised form. The number of patients undergoing the randomisation procedure, the number of patients who completed the study and the number of improved patients were extracted. In addition, group mean scores at the end of the trial on Hamilton Depression Scale or any other depression scale were extracted. In the tolerability analysis, the number of patients failing to complete the study and the number of patients complaining of side-effects were extracted.

MAIN RESULTS

A total number of 194 studies were included in the review. The estimate of the overall odds ratio (OR) for responders showed that more subjects responded to amitriptyline in comparison with the control antidepressant group (OR 1.12 to 95% confidence interval (CI) 1.02 to 1.23, number needed to treat to benefit (NNTB) = 50). The estimate of the efficacy of amitriptyline and control agents on a continuous outcome revealed an effect size which also significantly favoured amitriptyline (Standardised Mean Difference (SMD) 0.13, 95% CI 0.04 to 0.23). Whilst these differences are statistically significant, their clinical significance is less clear. When the efficacy analysis was stratified by drug class, no difference in outcome emerged between amitriptyline and either tricyclic or selective serotonin reuptake inhibitor comparators. The dropout rate in patients taking amitriptyline and control agents was similar; however, the estimate of the proportion of patients who experienced side-effects significantly favoured control agents in comparison with amitriptyline (OR 0.66, 95% CI 0.59 to 0.74). When the tolerability analysis was stratified by drug class, the dropout rate in patients taking amitriptyline and the selective serotonin reuptake inhibitors significantly favoured the latter (OR 0.84, 95% CI 0.75 to 0.95, number needed to treat to harm (NNTH) = 40). When the responder analysis was stratified by study setting amitriptyline was more effective than control antidepressants in inpatients (OR 1.22, 95% CI 1.04 to 1.42, NNTB = 24), but not in outpatients (OR 1.01, 95%CI 0.88 to 1.17, NNTB = 200).

AUTHORS' CONCLUSIONS

This present systematic review indicates that amitriptyline is at least as efficacious as other tricyclics or newer compounds. However, the burden of side-effects in patients receiving it was greater. In comparison with selective serotonin reuptake inhibitors amitriptyline was less well tolerated, and although counterbalanced by a higher proportion of responders, the difference was not statistically significant.

Amitriptyline versus other types of pharmacotherapy for depression

BACKGROUND

For many years amitriptyline has been considered one of the reference compounds for the pharmacological treatment of depression. However, new tricyclic drugs, heterocyclic compounds and the selective serotonin reuptake inhibitors have been introduced on the market with the claim of a more favourable tolerability/efficacy profile.

OBJECTIVES

The aim of the present systematic review was to investigate the tolerability and efficacy of amitriptyline in comparison with the other tricyclic/heterocyclic antidepressants and with the selective serotonin reuptake inhibitors.

SEARCH STRATEGY

The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (2002-3) and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Key journals and conference abstracts were handsearched. Pharmaceutical companies were contacted for information on unpublished materials.

SELECTION CRITERIA

Only randomised controlled trials were included. Study participants were of either sex and any age with a primary diagnosis of depression. Included trials compared amitriptyline with another tricyclic/heterocyclic antidepressant or with one of the selective serotonin reuptake inhibitors.

DATA COLLECTION AND ANALYSIS

Data were extracted using a standardised form. The number of patients undergoing the randomisation procedure, the number of patients who completed the study and the number of improved patients were extracted. In addition, group mean scores at the end of the trial on Hamilton Depression Scale or any other depression scale were extracted. In the tolerability analysis, the number of patients failing to complete the study and the number of patients complaining of side-effects was extracted.

MAIN RESULTS

The estimate of the overall odds ratio for responders showed that more subjects responded to amitriptyline in comparison with the control antidepressant group (odds ratio 1.12, 95% confidence interval 1.01, 1.23, number needed to treat 50). The estimate of the efficacy of amitriptyline and control agents on a continuous outcome revealed an effect size which also significantly favoured amitriptyline (Standardised Mean Difference 0.13, 95% confidence interval 0.04, 0.23). Whilst these differences are statistically significant, their clinical significance is less clear. When the efficacy analysis was stratified by drug class, no difference in outcome emerged between amitriptyline and either tricyclic or selective serotonin reuptake inhibitor comparators. The dropout rate in patients taking amitriptyline and control agents was similar; however, the estimate of the proportion of patients who experienced side-effects significantly favoured control agents in comparison with amitriptyline (odds ratio 0.63, 95% confidence interval 0.56, 0.71). When the tolerability analysis was stratified by drug class, the dropout rate in patients taking amitriptyline and the selective serotonin reuptake inhibitors significantly favoured the latter (odds ratio 0.84, 95% confidence interval 0.75,0.95, number needed to harm 40). When the responder analysis was stratified by study setting amitriptyline was more effective than control ADs in inpatients (odds ratio 1.22, 95% confidence interval 1.04, 1.42, number needed to treat 24), but not in outpatients (odds ratio 1.01, 95% confidence interval 0.88, 1.17, number needed to treat = 200).

REVIEWER'S CONCLUSIONS

This present systematic review indicates that amitriptyline is at least as efficacious as other tricyclics or newer compounds. However, the burden of side-effects in patients receiving it was greater. In comparison with the selective serotonin reuptake inhibitors amitriptyline was less well tolerated, and although counterbalanced by a higher proportion of responders, the difference was not statistically significant.

Comprehensive survey of the relationship between serum concentration and therapeutic effect of amitriptyline in depression

The relationship between serum concentration (C(s)) of amitriptyline and its therapeutic effect in depression has been investigated frequently over the last 3 decades; however, the results were controversial and no consensus was reached. Therefore, we have performed a comprehensive survey and meta-analysis of the subject. All relevant literature was included, and the design of studies on the serum concentration-therapeutic effect relationship (SCTER) of amitriptyline was evaluated. Pooled original data from SCTER studies with adequate design were analysed by various statistical methods: regression analysis of therapeutic effect and C(s); comparison of the mean therapeutic effect in various ranges of C(s); dichotomisation of outcome and analysis according to sensitivity of receiver operation curves; frequency of responders and nonresponders in ranges determined by points of sensitivity; analysis of the distribution of C(s) in responders and nonresponders; logistic regression of responders and nonresponders with C(s) and other independent variables; calculation of effect size (g) and mean effect size (g(m)). Forty-five SCTER studies of amitriptyline were identified, and 27 studies met the minimum criteria of adequate study design. Inadequate study design predicted the finding of no SCTER. Analysis of the pooled data from studies with adequate design confirmed a therapeutic window of the sum of C(s) of amitriptyline and its active metabolite nortriptyline of about 80 to 200 microg/L. A moderate and significant positive g(m) (0.538, 95% confidence interval 0.167 to 0.909) was calculated for treatment with C(s) within the therapeutic window in comparison with treatment with C(s) outside the therapeutic window (19 studies with adequate design and original data available, n = 583). In conclusion, the evidence for a biphasic SCTER of amitriptyline in depression is considerably improved, and the results may help to find a consensus in the future. However, the clinical benefit of therapeutic drug monitoring of amitriptyline can only be demonstrated in a controlled and randomised study. Furthermore, the results provide further evidence that antidepressants at optimum C(s) are superior to placebo in the treatment of depression.

Amitriptyline v. the rest: still the leading antidepressant after 40 years of randomised controlled trials

BACKGROUND

Tricyclic antidepressants have similar efficacy and slightly lower tolerability than selective serotonin reuptake inhibitors (SSRIs). However, there are no systematic reviews assessing amitriptyline, the reference tricyclic drug, v. other tricyclics and SSRIs directly.

AIMS

To review the tolerability and efficacy of amitriptyline in the management of depression.

METHOD

A systematic review of randomised controlled trials (RCTs) comparing amitriptyline with other tricyclics/heterocyclics or with an SSRI.

RESULTS

We reviewed 186 RCTs. The overall estimate of the efficacy of amitriptyline revealed a standardised mean difference of 0.147 (95% CI 0.05-0.243), significantly favouring amitriptyline. The overall OR for dropping out was 0.99 (95% CI 0.91-1.08) and that for side-effects was 0.62 (95% CI 0.54-0.70), favouring the control drugs. With drop-outs included as treatment failures, the estimate of the effectiveness of amitriptyline v. tricyclics/heterocyclics and SSRIs showed a 2.5% difference in the proportion of responders in favour of amitriptyline (number needed to treat 40, CI 21-694; OR 1.12 (95% CI 1.01-1.24)).

CONCLUSIONS

Amitriptyline is less well tolerated than tricyclics/heterocyclics and SSRIs, but slightly more patients treated on it recover than on alternative antidepressants.

Nortriptyline blood levels and clinical outcome: meta-analysis of published studies

INTRODUCTION: An optimum range has been suggested for nortriptyline blood levels, above or below which patients respond poorly or do not respond at all to treatment. METHODS: A meta-analysis of published studies was performed to verify the existence of an optimal blood concentration range or therapeutic window in nortriptyline-treated depression patients. A MEDLINE search through the years 1970-1999 was carried out to identify original papers and review articles. Data concerning blood levels and percentage improvement were obtained concerning all included pacients. Univariate and multivariate analyses were performed for data comparison. Possible confounding variables, such as pre-treatment, setting (in or outpatients), and duration of treatment were also evaluated. RESULTS: From the 22 published studies found, only six of them with patients' individual data were included. We found an optimal range for nortriptyline concentrations (OR= 2.25, 95% CI = 1.15 to 4.39, p= 0.02). CONCLUSIONS: There may be a biphasic relationship of efficacy to plasma concentrations of nortriptyline, with a therapeutic window between 46 to 236 ng/ml.

Simulated home treatment of depression with nortriptyline

1. Twenty-two patients hospitalized for treatment of depression were treated under conditions simulating those of home treatment. 2. Full doses of nortriptyline, from 100 to 150 mg/day, were started after baseline observations were made. 3. Two patients were dropped from the study, one for orthostatic hypotension, one for an aberrant response to nortriptyline. Two additional patients developed orthostasis which was easily managed. Otherwise no unusual side effects were noted. 4. After six days of treatment, 9 of 20 patients showed significant improvement with an overall reduction in scores on the Hamilton Depression Scale of 49% for the entire group. 5. Using the weight-adjusted dosage schedule, 18 of the 21 patients attained plasma concentrations of nortriptyline within the presumed therapeutic range; however, no clear relationship could be established between plasma concentrations and clinical response. 6. With proper selection of patients, it should be possible to treat at home some patients who currently are considered to require hospitalization.