Flunarizine as maintenance treatment of a patient with bipolar disorder

Calcium Channel Antagonists for Mood Disorders

PURPOSE

Development of new thymoleptic medications has primarily centered on anticonvulsants and antipsychotic drugs. Based on our studies of intracellular calcium ion signaling in mood disorders, we were interested in the use of novel medications that act on this mechanism of neuronal activation as potential mood stabilizers.

METHOD

We reviewed the dynamics of the calcium second messenger system and the international body of data demonstrating increased baseline and stimulated intracellular calcium levels in peripheral cells of patients with bipolar mood disorders. We then examined studies of the effect of established mood stabilizers on intracellular calcium ion levels and on mechanisms of mobilization of this second messenger. After summarizing studies of calcium channel blocking agents, whose primary action is to attenuate hyperactive intracellular calcium signaling, we considered clinical experience with this class of medications and the potential for further research.

FINDINGS

Established mood stabilizers normalize increased intracellular calcium ion levels in bipolar disorder patients. Most case series and controlled studies suggest an antimanic and possibly mood stabilizing effect of the calcium channel blocking medications verapamil and nimodipine, with fewer data on isradipine. A relatively low risk of teratogenicity and lack of cognitive adverse effects or weight gain suggest possible applications in pregnancy and in patients for whom these are considerations.

IMPLICATIONS

Medications that antagonize hyperactive intracellular signaling warrant more interest than they have received in psychiatry. Further experience will clarify the applications of these medications alone and in combination with more established mood stabilizers.

Neuropsychiatric effects of cardiovascular drug therapy

Various cardiovascular drugs have been shown to have neuropsychiatric effects that can be harmful or therapeutically beneficial to patients. As an example, both sedation and mental depression have been described in patients receiving centrally acting antihypertensive drugs and beta-adrenergic blockers, related to their antiadrenergic actions. In contrast, because of these antiadrenergic actions, agents like clonidine have been used to treat opiate, alcohol, and nicotine withdrawal, while beta blockers have been used to treat symptoms of performance anxiety, migraine, and psychocardiac disorders. Some antiarrhythmic drugs have been associated with delirium, and digitalis toxicity has been shown to cause hallucinations, mania, euphoria, and depression. The calcium-channel blocker verapamil has been used as an adjunctive treatment in patients with bipolar disorders. Since neuropsychiatric symptoms are seen in patients with cardiovascular disease, clinicians should be aware of the possible relationship between these symptoms and concurrent cardiovascular drug therapy.

Calcium channel blockers in psychiatric disorders: a review of the literature

OBJECTIVES

To review the published literature of the past 15 years regarding use of calcium channel blockers (CCBs) in psychiatric practice. These drugs, especially verapamil, have been recommended as possible treatments for mania and other disorders.

METHODS

The Cumulative Medical Index and other databases were searched and back-tracked to locate relevant articles. Sixty-one such articles were uncovered: 37 anecdotal reports, 7 partially controlled reports, and 17 controlled trials.

RESULTS

Most studies involved treatment of mania using verapamil. Although anecdotal reports were generally favourable, results from partially controlled reports or controlled clinical trials were mixed. Generally, verapamil was less effective than was lithium or placebo. Treatment of depression with CCBs was not very successful, regardless of the type of trial; the best trial was negative. The same was true for the treatment of schizophrenia, although the cases studied were extremely chronic and treatment-resistant. Evidence for efficacy in other illnesses, such as Alzheimer's disease or tardive dyskinesia was scanty but suggested that further trials might be in order.

CONCLUSIONS

CCBs do not at present have an established place in psychiatric treatment. Nonetheless, clinicians faced with a manic patient not responsive to other antimanic drugs, either alone or in combination, might consider adding verapamil as an adjunct. A study bearing on this specific issue is needed to determine whether or not such off-label use would really be justified.

Preliminary controlled trial of nimodipine in ultra-rapid cycling affective dysregulation

We report the initial results of the first controlled double-blind trial of nimodipine, a calcium channel antagonist, in the acute and prophylactic treatment of patients with treatment-refractory affective dysregulation. Active drug nimodipine (A) was substituted for placebo (B) in 12 patients. Patients were studied in a B-A-B design, with 3 of the 12 patients rechallenged with active drug in a B-A-B-A design (patients 9, 10, and 11). Five of the nine patients who completed the drug trial responded. One of three patients suffering from ultra-ultra-rapid (ultradian) cycling bipolar II disorder (patient 6) showed an essentially complete response; the other two ultradian patients (patients 4 and 9) showed evidence of a partial response on manic and depressive oscillations, one of which was confirmed in a B-A-B-A design. Only one of five less rapidly, but continuously cycling patients showed an excellent response (patient 10), and this was confirmed in a B-A-B-A design. The one patient who had recurrent brief depression (patient 11) showed a complete resolution of severe depressive recurrences, with response re-confirmed in an extended prophylactic trial with a B-A-B-A design. In the eight patients who completed self-ratings, nimodipine was associated with a significant reduction in the magnitude of mood fluctuations compared with the baseline placebo condition. Further clinical study of nimodipine, a calcium channel blocker with a unique profile of behavioral and anticonvulsant properties, appears warranted in patients with treatment-refractory affective illness characterized by recurrent brief depression and ultradian cycling.