DRAMATIC PROPHYLACTIC RESPONSE TO NIMODIPINE: A Case Report
(This is an invited contribution by Robert Westhead.)
This 50 year old man had a lifetime of incapacitating rapid cycling (10 days up and 10 days down) bipolar I disorder, but then for the past 4 years has had a complete remission on nimodipine (60mg QID). He remains on lithium (800mg), and of his other long-term medications, he has titrated quetiapine down from 800mg to 50mg and has discontinued phenelzine.
He had previously failed to respond to combinations of:
· Lithium
· Anticonvulsant mood stabilizers (including divalproex sodium, lamotrigine, carbamazepine and pregablin)
· Atypical antipsychotics (including quetiapine, aripiprazole and lurasidone)
· Antidepressants (including SSRIs eg citalopram and sertraline, NSRIs eg venlaflaxine and mirtazapine, and a MAOI eg phenelzine)
· Thyroxine
· Propranolol
· Clonazepam
He wanted to highlight this dramatic response to nimodipine in combination with lithium as this dihydropyridine calcium channel blocker is not well known or frequently used for its prophylactic effectiveness.
He noted that as well as stopping the rapid cycling, the nimodipine has provided complete relief from comorbid social anxiety symptoms and remediated cognitive and memory impairment.
This response to nimodipine potentially also has pathophysiological implications. Nimodipine directly blocks the CACNA1C calcium influx gene that has repeatedly been associated with vulnerability to depression, bipolar disorder, and schizophrenia in gene wide association studies. This patient does not know whether he carries this gene variant, but assays for it are routinely available as performed by the company Genomind.
Thus, it remains an open question as to whether those who have the CACNA1C variant would be more responsive to nimodipine compared to those without the variant. Certainly, the efficacy of this agent in treatment of patients with bipolar disorder deserves further consideration and study.
