[Clinical double-blind study with two different dosages of maprotiline (150 and 225 mg per day) (author's transl)]

Is dose escalation of antidepressants a rational strategy after a medium-dose treatment has failed? A systematic review

BACKGROUND

Maximizing the dose of antidepressants is widely recommended in cases of non-response to medium-dose treatment. However, scientific evidence supporting high-dose treatment is scarce. Systematic studies comparing dose escalation with alternative strategies for refractory depression (i. e. augmentation or change of compound) are lacking. The aim of this publication is to review available direct and indirect evidence concerning dose increase of antidepressants after a medium-dose trial has failed.

METHOD

We performed a systematic literature search of Medline (1966-2003) and reviewed studies and publication references for available evidence.

DATA SOURCES AND STUDY SELECTION

Studies of the following types were included: 1) dose increase studies in treatment refractory patients, 2) comparative dose studies, 3) therapeutic drug monitoring studies.

RESULTS

Available data suggest differential efficacy of various pharmacological classes at more than medium-dosage. Direct evidence shows no increase of efficacy with high-dose selective serotonin reuptake inhibitor (SSRI) treatment; however, indirect evidence suggests enhanced therapeutic efficacy with high-dose tricyclic antidepressants. Few clinical data show ultra-high-dose treatment with the irreversible monoamine-oxidase-(MAO-) inhibitor tranylcypromine to be effective for refractory depression. Data concerning other selective compounds are insufficient to allow any definitive conclusion on the benefit of high-dose treatment.

CONCLUSIONS

Based on available data highdose antidepressant treatment of patients refractory to medium-dose treatment is recommended for tricyclic compounds but not for SSRI. Some data suggest beneficial efficacy of ultra-high doses of the irreversible MAOI tranylcypromine. Research on other substance groups is limited and inconclusive. Prospective studies comparing dose escalation with alternative strategies for treatment of non-responding patients are needed.

A double-blind controlled study of clinical efficacy of maprotiline and amitriptyline in depression

A multiclinic double-blind controlled study was performed on the effects of MAP in both inpatients and outpatients with AMT as control drug. 1. Subjects consisted of 41 male and 45 female patients suffering from various types of depression. MAP was assigned to 42 cases and AMT to 44 cases. Of these patients, 14 MAP cases and 10 AMT cases were subsequently dropped for a variety of reasons to obtain 28 MAP cases and 34 AMT cases as evaluable. 2. The global improvement ratings were compared and found not significantly different for any week between the two treatments. 3. The global improvement ratings by the characteristic features of patients did not show any significant difference in any items studied between the two treatments. 4. The symptomatic improvement ratings (on the Hamilton R.S. for assessment by the physician) indicated that AMT was more effective on "anxiety (psychic)." 5. The symptomatic improvement ratings (on the Beck self-assessment scale by the patient) indicated that MAP was more effective on "work" and AMT on "pathos", "feeling of satisfaction", "withdrawal" and "loss of libido." 6. During the treament period, 74.3 percent of the MAP group and 76.9 percent of the AMT group of patients showed some side effects of accompanying symptoms, with no significant difference recognized between the two treatments. Itemwise, however, the incidence of tremor was significantly lower (p-=0.06) in the MAP group. Moreover, the MAP group tended to be less liable to such anticholinergic side effects as dry mouth, constipation, trouble of accomodation, urinary disturbance and palpitation. 7. On the basis of the above findings, it is concluded that MAP is as effective against depression as AMT and less liable to the anticholinergic side effects. It is, therefore, a very useful antidepressant.