Pramipexole: augmentation in the treatment of depressive symptoms

Pramipexole Augmentation for Treatment-Resistant Unipolar and Bipolar Depression in the Real World: A Systematic Review and Meta-Analysis

BACKGROUND

Pramipexole is a dopamine full agonist approved for the treatment of Parkinson's disease and restless legs syndrome. Its high affinity for the D3 receptor and neuroprotective, antioxidant, and anti-inflammatory activity provides a rationale for the treatment of depression. In this paper, we review studies on the effectiveness and safety of antidepressant pramipexole augmentation in treatment-resistant depression.

METHODS

This comprehensive systematic review and meta-analysis of observational studies on pramipexole-antidepressant augmentation included patients with resistant unipolar and bipolar depression. The primary outcome measure was the treatment response, measured at the study endpoint.

RESULTS

We identified 8 studies including 281 patients overall, 57% women and 39.5% with bipolar disorder and 60.5% with major depressive disorder. The mean follow-up duration was 27.3 weeks (range 8-69). The pooled estimate of treatment response was 62.5%, without significant differences between unipolar and bipolar depression. Safety was good, with nausea and somnolence the most frequent side effects.

CONCLUSIONS

The findings of this systematic review, needing further confirmation, show that off-label use of pramipexole as augmentation of antidepressant treatment could be a useful and safe strategy for unipolar and bipolar treatment-resistant depression.

Ropinirole Augmentation for Depression: A Randomized Controlled Trial Pilot Study

OBJECTIVE

Evidence both from animal and human studies suggests a role for dopaminergic pathways in the treatment of depression. Ropinirole, a selective agonist of dopamine D2/D3, is in use for the treatment of parkinsonism. Preliminary evidence suggests that such agonists might be useful as antidepressants. We tested whether an add-on ropinirole is an effective in depressed patients.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial of add-on ropinirole in depressed patients unresponsive to at least one antidepressant. We recruited 32 unipolar and bipolar patients who remained depressed (modified 21-item Hamilton Depression Rating Scale) despite at least 4 weeks of treatment with an adequate dose of antidepressant medication. Patients received either 2 mg of oral ropinirole or placebo twice daily added on to their current medication and were evaluated weekly for 7 weeks using the Hamilton Depression Rating Scale and Montgomery-Asberg Depression Rating Scale.

RESULTS

No difference in primary or secondary outcome measures was detected between the treatment and control groups.

DISCUSSION

These results differ from previous studies and are unexpected in light of theoretical considerations. This may indicate that there are differences in pharmacological activity between ropinirole and other dopaminergic agents such as pramipexole.

Ropinirole in Bipolar Disorder: Rate of Manic Switching and Change in Disease Severity

PURPOSE

To determine the effects of ropinirole on manic switching and disease severity in bipolar disorder.

DESIGN AND METHODS

A cross-sectional survey was conducted in 23 bipolar depressed patients using ropinirole combination therapy (Young Mania Rating Scale [YMRS], Bipolar Inventory of Symptoms Scale [BISS]). Retrospective Clinical Global Impression of Change (CGI-C) and CGI-S (Severity) were captured via chart review.

FINDINGS

One patient (4.3%) experienced induction of mania (YMRS). All patients responded or partially responded to ropinirole (CGIs). YMRS and BISS mania scores were correlated.

PRACTICE IMPLICATIONS

Ropinirole has a low rate of manic switching and significantly reduces bipolar depression severity.

An intricate relationship between pain and depression: clinical correlates, coactivation factors and therapeutic targets

INTRODUCTION

An apparent clinical relationship between pain and depression has long been recognized, which makes an enormous impact on the individual health care. At present, the practical implication of such overlapping symptomatology between pain and depression is not clear, but the prevalence estimates for depression are substantially inflated among patients with chronic pain and vice versa. This interaction has been labeled as the depression-pain syndrome or depression-pain dyad.

AREAS COVERED

This article discusses the neurobiological substrates and neuroanatomical pathways involved in pain-depression dyad along with newer therapeutic targets.

EXPERT OPINION

Several key themes emerged from our review of the relationship between depression and pain. First, the diagnosis of depression in pain or vice versa is particularly challenging, and the development of better diagnostic framework that involves both pain and depression is particularly required. Secondly, the entwined relationship between pain and depression supports the possibility of common coactivating factors that results in their neurophysiological overlap. A broad understanding of the role played by the central nervous system (CNS) in the processing of pain and depression may eventually lead to the introduction of triple reuptake inhibitors, agomelatine, vilazodone and ketamine with novel mechanism of action, hence appear to be of promising potential for pain with depression.

Pramipexole augmentation in treatment-resistant major depressive disorder

Evaluation of: Cusin C, Iovieno N, Iosifescu DV et al. A randomized, double-blind, placebo-controlled trial of pramipexole augmentation in treatment-resistant major depressive disorder. J. Clin. Psychiatry 74(7), e636-e641 (2013). To overcome limited efficacy in antidepressants, clinicians may choose augmentation, switching to a different antidepressant, or a combination of different antidepressant drugs based on the individual patient's clinical circumstances. Among such options for difficult-to-treat major depressive disorder (MDD) patients, augmentation therapy with atypical antipsychotics, psychostimulants, dopamine agonists, serotonin 1A partial agonists, lithium, and thyroid hormones are commonly used in clinical practice. In fact, augmentation therapy has some clinical merits and is more convenient than switching medications and combination approaches for treating MDD. One such augmentation agent, pramipexole has been proposed, and has been implicated in the development and treatment of MDD. Recently, randomized controlled trials with pramipexole augmentation have been conducted and have demonstrated that pramipexole is a safe and potentially efficacious augmentation strategy. This article will discuss currently available clinical trial data and the potential role of pramipexole in MDD treatment, including clinical significance, limitations, and future research directions.

[Anhedonia in depression]

Anhedonia, or markedly diminished interest or pleasure, is a hallmark symptom of major depression, schizophrenia, and other neuropsychiatric disorders. The term "anhedonia" was introduced by the French psychologist Ribot in 1896 to describe the counterpart to analgesia in his patients, for which "it was impossible to find the least pleasure". Over the last decades, the clinical definition of anhedonia has remained relatively unchanged, but recently, behavioral neurosciences have significantly changed our knowledge of reward-related processes. Now, the construct of anhedonia reflects deficits in hedonic capacity, and is closely linked to the processes of reward valuation, decision-making, anticipation, and motivation. The neural circuits underlying these reward-related mechanisms include essentially the ventral striatum and prefrontal cortical regions. Here, we review the clinical concepts, neural bases and psychopharmacological data related to the deficits of hedonia in depression. Understanding anhedonia will facilitate diagnosis and treatment management.

Assessing the roles of stimulants/stimulant-like drugs and dopamine-agonists in the treatment of bipolar depression

Bipolar depression is considered the most difficult-to-treat phase of bipolar disorder, in relation to its pervasiveness and efficacy and/or tolerability limitations of available treatments. Indeed, most mood stabilizers and atypical antipsychotics are not as effective in ameliorating depressive compared with manic symptoms, and entail substantial tolerability limitations. However, the use of antidepressants is highly controversial, as their efficacy appears less robust in bipolar compared with unipolar depression. In addition, antidepressants, in spite of generally having adequate somatic tolerability, in BD may be associated with a higher risk of manic/hypomanic switch, suicidality and rapid cycling. Among alternative pharmacological strategies, compounds with stimulant and pro-dopaminergic effects, such as methylphenidate, modafinil, armodafinil and pramipexole, have showed potential antidepressant activity, even though their use in clinical practice has been limited by the paucity of controlled evidence. This article seeks to review available evidence about the use of the aforementioned compounds in the treatment of bipolar depression. Findings from reviewed studies suggested that pro-dopaminergic compounds, such as pramipexole and stimulants/stimulant-like agents, deserve consideration as adjunctive therapies in bipolar depressed patients, at least in some subgroups of patients. Nevertheless, caution regarding their use is recommended as further clinical trials with larger samples and longer follow-up periods are necessary to clarify the roles of these medications in bipolar depression.

The potential and limitations of DOV 216,303 as a triple reuptake inhibitor for the treatment of major depression: a microdialysis study in olfactory bulbectomized rats

DOV 216,303 belongs to a new class of antidepressants, the triple reuptake inhibitors (TRIs), that blocks serotonin, norepinephrine and dopamine transporters and thereby increases extracellular brain monoamine concentrations. The aim of the present study was to measure extracellular monoamine concentrations both in the prefrontal cortex (PFC) and dorsal hippocampus (DH) after chronic administration of DOV 216,303 in the OBX animal model of depression and to compare the effects with acute drug treatment. OBX animals showed lower dopamine levels in PFC upon acute administration of DOV 216,303 than sham animals for up to five weeks after surgery. No such changes were observed in the DH. Unexpectedly, a DOV 216,303 challenge in chronic DOV 216,303 treated sham animals resulted in a blunted dopamine response in the PFC compared to the same challenge in vehicle treated animals. This blunted response probably reflects pharmacokinetic adaptations and/or pharmacodynamic changes, since brain and plasma concentrations of DOV 216,303 were significantly lower after chronic administration compared to acute administration. Surprisingly, and in contrast what we have reported earlier, chronic DOV 216,303 treatment was unable to normalize the hyperactivity of the OBX animals. Interestingly, by measuring the drug plasma and brain levels, it was demonstrated that at the time of behavioral testing (24 h after last drug treatment) DOV 216,303 was not present anymore in either plasma or brain. This seems to indicate that this putative antidepressant drug has no lasting antidepressant-like behavioral effects in the absence of the drug in the brain.

Responsiveness of motor and nonmotor symptoms of Parkinson disease to dopaminergic therapy

BACKGROUND

The duration of clinical control of motor symptoms of Parkinson disease (PD) treated with levodopa/carbidopa preparations eventually starts to shorten, a phenomenon known as end-of-dose "wearing off." The involvement of core nonmotor symptoms of "wearing off" (depressed mood, pain/aching, anxiety, and cloudy/slowed thinking) is not well understood.

METHODS

A post hoc analysis from a study to validate the self-rated 9-item, Wearing-Off Questionnaire (WOQ-9), which was designed to identify motor and nonmotor symptoms of "wearing off" in PD patients, was performed to compare the frequency and sensitivity of motor and nonmotor symptoms of "wearing off" from dopaminergic therapy.

RESULTS

Analysis of responses to the WOQ-9 from 216 PD patients found that individual nonmotor symptoms were reported by 25% to 50% and motor symptoms by 55% to 80% of patients. Individual nonmotor symptoms improved following the next dose of dopaminergic therapy in 43% to 53% of the patients who presented with such symptoms, whereas motor symptoms improved in 48% to 66% of the cases, suggesting both types of symptoms respond to dopaminergic therapies.

CONCLUSION

Nonmotor symptoms of PD appear sensitive to dopaminergic treatment. These symptoms resemble those seen with depressive, anxiety, and somatoform disorders suggesting potential shared mechanisms as well as possible treatment implications.