The long-term treatment with the Ca(2+)-antagonists nifedipine, verapamil, flunarizine and with the calmodulin antagonist trifluoperazine decreases the activity of 5-HT1 receptors in rat cerebral cortex and hippocampus

European Headache Federation (EHF) critical re-appraisal and meta-analysis of oral drugs in migraine prevention-part 2: flunarizine

OBJECTIVE

Novel disease-specific and mechanism-based treatments sharing good evidence of efficacy for migraine have been recently marketed. However, reimbursement by insurers depends on treatment failure with classic anti-migraine drugs. In this systematic review and meta-analysis, we aimed to identify and rate the evidence for efficacy of flunarizine, a repurposed, first- or second-line treatment for migraine prophylaxis.

METHODS

A systematic search in MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov was performed for trials of pharmacological treatment in migraine prophylaxis, following the Preferred Reporting Items for Systematic Reviews (PRISMA). Eligible trials for meta-analysis were randomized, placebo-controlled studies comparing flunarizine with placebo. Outcomes of interest according to the Outcome Set for preventive intervention trials in chronic and episodic migraine (COSMIG) were the proportion of patients reaching a 50% or more reduction in monthly migraine days, the change in monthly migraine days (MMDs), and Adverse Events (AEs) leading to discontinuation.

RESULTS

Five trials were eligible for narrative description and three for data synthesis and analysis. No studies reported the predefined outcomes, but one study assessed the 50% reduction in monthly migraine attacks with flunarizine as compared to placebo showing a benefit from flunarizine with a low or probably low risk of bias. We found that flunarizine may increase the proportion of patients who discontinue due to adverse events compared to placebo (risk difference: 0.02; 95% CI -0.03 to 0.06).

CONCLUSIONS

Published flunarizine trials predate the recommended endpoints for evaluating migraine prophylaxis drugs, hence the lack of an adequate assessment for these endpoints. Further, modern-day, large-scale studies would be valuable in re-evaluating the efficacy of flunarizine for the treatment of migraines, offering additional insights into its potential benefits.

Multitargeting in cardioprotection: An example of biaromatic compounds

A multitarget drug design approach is actively developing in modern medicinal chemistry and pharmacology, especially with regard to multifactorial diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. A detailed study of many well-known drugs developed within the single-target approach also often reveals additional mechanisms of their real pharmacological action. One of the multitarget drug design approaches can be the identification of the basic pharmacophore models corresponding to a wide range of the required target ligands. Among such models in the group of cardioprotectors is the linked biaromatic system. This review develops the concept of a "basic pharmacophore" using the biaromatic pharmacophore of cardioprotectors as an example. It presents an analysis of possible biological targets for compounds corresponding to the biaromatic pharmacophore and an analysis of the spectrum of biological targets for the five most known and most studied cardioprotective drugs corresponding to this model, and their involvement in the biological effects of these drugs.

Verapamil and Alzheimer's Disease: Past, Present, and Future

Verapamil is a phenylalkylamine class calcium channel blocker that for half a century has been used for the treatment of cardiovascular diseases. Nowadays, verapamil is also considered as a drug option for the treatment of several neurological and psychiatric disorders, such as cluster headache, bipolar disorders, epilepsy, and neurodegenerative diseases. Here, we review insights into the potential preventive and therapeutic role of verapamil on Alzheimer’s disease (AD) based on limited experimental and clinical data. Pharmacological studies have shown that verapamil has a wide therapeutic spectrum, including antihypertensive, anti-inflammatory, and antioxidative effects, regulation of the blood-brain barrier function, due to its effect on P-glycoprotein, as well as adjustment of cellular calcium homeostasis, which may result in the delay of AD onset or ameliorate the symptoms of patients. However, the majority of the AD individuals are on polypharmacotherapy, and the interactions between verapamil and other drugs need to be considered. Therefore, for an appropriate and successful AD treatment, a personalized approach is more than necessary. A well-known narrow pharmacological window of verapamil efficacy may hinder this approach. It is therefore important to note that the verapamil efficacy may be conditioned by different factors. The onset, grade, and brain distribution of AD pathological hallmarks, the time-sequential appearances of AD-related cognitive and behavioral dysfunction, the chronobiologic and gender impact on calcium homeostasis and AD pathogenesis may somehow be influencing that success. In the future, such insights will be crucial for testing the validity of verapamil treatment on animal models of AD and clinical approaches.

Verapamil Blocks Scopolamine Enhancement Effect on Memory Consolidation in Passive Avoidance Task in Rats

Our recent data have indicated that scopolamine, a non-selective muscarinic receptor antagonist, improves memory consolidation, in a passive avoidance task, tested in rats. It has been found that verapamil, a phenylalkylamine class of the L-type voltage-dependent calcium channel antagonist, inhibits [3H] N-methyl scopolamine binding to M1 muscarinic receptors. However, there are no data about the effect of verapamil on memory consolidation in the passive avoidance task, in rats. The purpose of the present study was to examine the effects of verapamil (0.5, 1.0, 2.5, 5.0, 10, or 20 mg/kg i.p.) as well as the interaction between scopolamine and verapamil on memory consolidation in the step-through passive avoidance task, in Wistar rats. Our results showed that verapamil (1.0 and 2.5 mg/kg) administered immediately after the acquisition task significantly increased the latency of the passive avoidance response, on the 48 h retested trial, improving memory consolidation. On the other hand, verapamil in a dose of 5 mg/kg, that per se does not affect memory consolidation, significantly reversed the memory consolidation improvement induced by scopolamine (1 mg/kg, i.p., administered immediately after verapamil treatment) but did not change the passive avoidance response in rats treated by an ineffective dose of scopolamine (30 mg/kg). In conclusion, the present data suggest that (1) the post-training administration of verapamil, dose-dependently, improves the passive avoidance response; (2) verapamil, in ineffective dose, abolished the improvement of memory consolidation effect of scopolamine; and (3) exists interaction between cholinergic muscarinic receptors and calcium homeostasis-related mechanisms in the consolidation of emotional memory.

Flunarizine versus topiramate for chronic migraine prophylaxis: a randomized trial

OBJECTIVES

Chronic migraine (CM) is a prevalent and devastating disorder with limited therapeutic options. This study explored the efficacy of 10 mg/d flunarizine for CM prophylaxis as compared with 50 mg/d topiramate.

METHODS

We conducted a prospective, randomized, open-label, blinded-endpoint trial. Patients with CM were randomized to flunarizine and topiramate treatment. The primary outcomes assessed were the reductions in the total numbers of headache days and migraine days after 8 weeks of treatment. Secondary outcomes were reductions in the numbers of days of acute abortive medication intake and acute abortive medication tablets taken, and the 50% responder rate.

RESULTS

Sixty-two subjects were randomized (n=31/group). Patients treated with flunarizine showed significant reductions in the numbers of total headache days (-4.9 vs -2.3, P=.012) and migraine days (-4.3 vs -1.4, P=.001) compared with those treated with topiramate. Patients treated with flunarizine also showed significant reductions in the numbers of days of acute abortive medication intake (-2.3 vs -0.2, P=.005) and acute abortive medication tablets taken (-4.6 vs -0.5, P=.005) and had a higher 50% responder rate in terms of total headache days (58.6% vs 25.9%, P=.013) and migraine days (75.9% vs 29.6%, P=.001), compared with topiramate-treated patients. Flunarizine was generally well tolerated and had a safety profile comparable to that of topiramate.

CONCLUSIONS

Our results suggest that, in an 8-week study, 10 mg/d flunarizine is more effective than 50 mg/d topiramate for CM prophylaxis.

Transcranial Doppler evaluation of cerebral hemodynamics in migraineurs during prophylactic treatment with flunarizine

Transcranial Doppler (TCD) recording was used to evaluate the mean flow velocity (MFV) and cerebrovascular reactivity to CO2 in 21 migraineurs during the interictal phase. Nine were affected by migraine with aura (MwA) and 12 by migraine without aura (MwoA). During each session the middle cerebral artery (MCA) flow velocity was examined in basal conditions, in hypocapnia after a 3-min period of hyperventilation, in basal conditions a second time, and in hypercapnia after breath-holding. The same procedure was followed in a group of 21 age- and sex-matched volunteers. Recordings were performed before (T1), during (T2), and after (T3) prophylactic treatment with flunarizine (10 mg/day for 2 months) to assess the possible effect of this drug on cerebral hemodynamics. In basal condition, increased MFV values were found in both MwA and MwoA patients. In MwA patients the reactivity index (RI) to hypocapnia was significantly increased in T1 (p < 0.05). This abnormal cerebrovascular reactivity disappeared during flunarizine treatment (T2) and in the post-therapy period (T3).