Fluoxetine severe depression

Two studies have compared milnacipran, in the recommended dose of 50 mg twice daily, with SSRIs in patients with severe depression, reviewed recently by Lopez-Ibor and colleagues [1996]. Both studies reported a significant advantage for milnacipran, measured on the MADRS, compared with fluoxetine given in a dose of 20 mg/day or fluvoxamine given in a dose of 100 mg twice a day. The size of the effect was substantial in the combined studies, the advantage for milnacipran compared with that for the SSRIs was more than 4 points. 

With this caveat in mind, each side of the debate has evidence to support its position. The evidence is first summarized supporting the position that SSRIs are less effective than are some other antidepressants (particularly those with dual effects on both serotonin and NE CNS systems) in patients with more severe depression or who are hospitalized. Danish investigators in two double-blind, active-controlled studies found that clomipramine produced a superior response with either paroxetine or citalopram in the treatment of patients hospitalized for major depression (116, 117). Two double-blind studies also have shown that venlafaxine and mirtazapine were more effective than fluoxetine in patients hospitalized with depression ( 114,118). Finally, there are studies showing that the addition of desipramine (one of the most selective NE reuptake inhibitors) to an SSRI can convert nonresponders or pamal responders to full response ( 119, 119a, 120). 

Antidepressants Pharmaceutical drugs prescribed for the treatment of persistent and severe depression. Imipramine (Tofranil), amitriptyline (Elavil), and fluoxetine (Prozac) are examples. 

Reboxetine. Most of the activity of rehoxetine resides in the 5.5 isomer (The marketed compound is RR and 55.) It is claimed to he superior to fluoxetine in severe depression. It is marketed in Europe. At least three tricyclic compounds, desipramine. nortriptyline, and the technically tetracyclic maprotiline are SNERIs. They, of course, have typical characteristic TCA side effects but lower anticholinergic and H -antihistaminic (sedative) effects than dimethyl compounds. SNERIs arc clinically effective antidepressants. 

The initial dose of SSRI is similar to that used in depression. Patients should be titrated as tolerated to response. Many patients will require maximum recommended daily doses. Patients with comorbid panic disorder should be started on lower doses (Table 37-4). When discontinuing SSRIs, the dose should be tapered slowly to avoid withdrawal symptoms, with the possible exception of fluoxetine. Relapse rates may be as high as 50%, and patients should be monitored closely for several weeks.58 Side effects of SSRIs in SAD patients are similar to those seen in depression and most commonly include nausea, sexual dysfunction, somnolence, and sweating. 

A breakthrough in the treatment of major depression was the discovery of fluoxetine, marketed as Prozac. Fluoxetine has a mechanism of action similar to that of imipramine with an important exception. It is a selective serotonin reuptake inhibitor, an SSRI. This strongly suggests that, in some sense, the symptoms of major depression result from a deficit in serotonin specifically. By inhibiting its reuptake from the synapse, the activity of serotonin is enhanced. Two other important drugs for major depression, sertraline (Zoloft) and paroxetine (Paxil), among several others,... 

Buspirone (BuSpar) [Anxiolytic] WARNING Closely monitor for worsening depression or emergence of suicidality Uses Short-term relief of anxiety Action Antianxiety antagonizes CNS serotonin receptors Dose Initial 7.5 mg PO bid T by 5 mg q2-3d to effect usual 20-30 mg/d max 60 mg/d Contra w/ MAOI Caution [B, /-] Avoid w/ severe hepatic/renal insuff Disp Tabs SE Drowsiness, dizziness, HA, N, EPS, serotonin synd, hostility, depression Notes No abuse potential or physical/psychologic d endence Interactions T Effects W/ erythromycin, clarithromycin, itraconazole, ketoconazole, diltiazem, verapamil, grapefruit juice effects W/ carbamazepine, rifampin, phenytoin, dexamethasone, phenobarbital, fluoxetine EMS T Sedation w/ concurrent EtOH use grapefruit juice may T risk of adverse effects OD May cause dizziness, miosis, N/V symptomatic and supportive... 

As other indications are sought for the SSRls, it is clear that their action extends beyond depression, dysthymia, and the anxiety disorders, and the broad spectrum of therapeutic action of these antidepressants becomes apparent. For example, based on the evidence from placebo-controlled studies [A. Wood 1993], fluoxetine has been licensed in Europe for the treatment of bulimia, and several SSRls are reported to be effective in the treatment of premenstrual syndrome. 

TCAs in more serious forms of depression such as melancholic or psychotic depression. Some studies have suggested that the SSRls do not work as well as the TCAs in melancholic depression (Roose et al. 1994]. Likewise, one study has suggested that venlafaxine, a drug with a mechanism of action similar to that of the TCAs, was superior to fluoxetine in the treatment of inpatients with melancholic depression (Clerc et al. 1994]. Still, other metaanalyses have failed to find a difference in the efficacy of SSRls versus TCAs in serious forms of depression [Nierenberg 1994]. Nonetheless, given that most studies have employed TCAs, and some debate exists about the utility of SSRls in severe subtypes, it may be prudent to start with a TCA in most patients until the debate is further resolved. For patients who present a significant suicide risk or who have not been able to tolerate TCAs, the SSRls in combination with a standard antipsychotic appears an effective option. 

Fluoxetine has been the subject of four reports in the treatment of social phobia. However, no double-blind, control studies have been reported. Preliminary results suggest that fluoxetine is effective in social phobia. Doses ranged from 10 to 100 mg/day. The onset of symptom resolution was variable among subjects. A justifiable approach to treatment with fluoxetine would be to implement an approach similar to that in the treatment of depression. One would start with a dose of 10-20 mg/day and titrate slowly upward over a period of several weeks. A duration of at least 6 weeks would be recommended as a minimum trial of this agent, with 12 weeks perhaps affording a better opportunity to assess the full measure of improvement. 

Several trials have been performed with antidepressants in the prevention of recurrence of major depression. In an exemplary trial of this kind, Reimherr et al. (1998) explored the optimal length of therapy in a long-term, placebo-controlled continuation study of patients who had responded to 12 14 weeks of open-label fluoxetine treatment (20mg/day) for major depression. Different maintenance schedules were represented by four treatment arms ... 

There have been five double-blind studies comparing the antidepressant efficacy of different SSRIs versus different TCAs in patients with HDRS scores of 25 or more (122, 123,124, 125 and 126). Three of these studies permitted inclusion of both inpatients and outpatients ( 122, 123 and 124), whereas the other two were solely done in outpatients (125, 126). Three were placebo-controlled (1.23, 125,126). In these three studies, the SSRI (i.e., fluvoxamine, paroxetine, or sertraline) was either superior to both the f CA and placebo or was comparable with the TCA and superior to placebo. In the other two studies, the SSRI was not different from the TCA and there was no placebo control. There have also been four studies and one metaanalysis of European clinical trials which found no difference in antidepressant efficacy between several different SSRIs and several different tertiary amine TCAs in patients hospitalized for major depression ( 127,128, 129,130 and 131). Finally, there have been two relatively small studies showing that fluoxetine and fluvoxamine both had antidepressant efficacy superior to placebo in patients with melancholia ( 132, 133). Another larger study failed to find a difference between paroxetine and amitriptyline in treating such patients ( 134). 

Most efficacy trials with reboxetine have so far only been published in review articles ( 178). Most of these articles did not have peer review and do not contain the full details concerning methodology or results. This fact limits the ability to accurately determine its relative efficacy and tolerability. In short-term (4 to 8 weeks), placebo-controlled clinical trials, reboxetine produced a response (defined as at least a 50% reduction in severity scores) in 56% to 74% of patients. These results were statistically superior to placebo in most studies. Reboxetine was also found to be as effective as imipramine and desipramine in four double-blind, randomized, active-controlled (but not placebo-controlled) studies involving more than 800 outpatients or inpatients with major depression. Reboxetine produced equivalent antidepressant response rates compared with fluoxetine in two clinical trials, one of which was also placebo-controlled. However, reboxetine was reported to have improved social motivation and behavior more than fluoxetine as assessed by the newly developed Social Adaptation Self-Evaluation Scale. In all of the studies, reboxetine had a similar time (i.e., 2 to 3 weeks) to onset of the antidepressant efficacy as do other antidepressants. 

Wheatley DP, van Moffaert M, Timmerman L, et al. Mirtazapine efficacy and tolerability in comparison with fluoxetine in patient with moderate to severe major depressive disorder. J din Psychiatry 1998 59 306-312. 

Pande AC, Sayler ME. Severity of depression and response to fluoxetine. Int Clin Psychopharmacol 1993 8 243-245. 

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