[Results of a prospective open study of therapy of sudden deafness with flunarizine]

The treatment effect of the lipophilic calcium antagonist flunarizine on the recovery of sudden hearing loss was evaluated in a prospective phase-II study. Thirty-seven patients presenting with recent and sudden onset of unilateral sensorineural hearing loss were treated with 50 mg flunarizine intravenously for the first two days followed by 10 mg flunarizine orally for four weeks. Pure-tone audiometry was done before the beginning of the treatment and after one and four weeks. The absolute and relative hearing gains after one and four weeks were compared to those of 67 similar patients previously treated with saline infusions and placebo tablets in the same institutions during a double blind study (Probst et al. Acta Otolaryngol. 112 (1992) 435-443). The mean absolute hearing gains of the flunarizine group was 17 dB and 21 dB, after one and four weeks respectively (placebo group: 16 dB and 24 dB). The corresponding relative hearing gains (defined as absolute gain divided by initial hearing loss) were 35% and 43% for the flunarizine group and 33% and 42% for the placebo group. We conclude that flunarizine treatment does not improve the recovery of sudden hearing loss.

Therapeutic effect of infused Fluosol-DA/carbogen with ephedrine, flunarizine, or nitroprusside

The perfluorochemical emulsion Fluosol-DA plus carbogen breathing has been shown to increase the effectiveness of radiation therapy in preclinical solid tumors when the emulsion was administered by i.v. bolus injection. Much of the enhancement in tumor radiation response was lost when the emulsion was administered slowly.

PURPOSE

We hypothesized that an increase in tumor perfusion resulted when Fluosol-DA was administered rapidly.

METHODS AND MATERIALS

In the present study, the alpha/beta agonist ephedrine, the Ca2+ channel blocker flunarizine and the nitric oxide producing vasodilating drug nitroprusside have been tested.

RESULTS

Ephedrine administration resulted in a decrease in the radiation plus Fluosol-DA +/- carbogen antitumor effects in both the Lewis lung carcinoma and FSaIIC tumor systems. In contrast, flunarizine administration resulted in an increase in the efficacy of the radiation plus carbogen and the radiation plus Fluosol-DA/carbogen in both tumor systems. Even with flunarizine administration Fluosol-DA delivered slowly was less effective than when the emulsion was given rapidly. Flunarizine with Fluosol-DA infused i.v. over 30 min followed by carbogen breathing prior to and during radiation therapy resulted in a 1.7-1.6-fold increase in response compared with 2.4-2.2-fold with Fluosol-DA administered by injection i.v. and carbogen breathing prior to and during radiation therapy using growth delay of the Lewis lung carcinoma. The effects of nitroprusside were complex. This drug had considerably more effect at 10 Gy than at higher radiation doses.

CONCLUSION

These studies suggest that Fluosol-DA given by i.v. injection may increase tumor perfusion and that a drug like flunarizine may be beneficial if the Fluosol-DA is administered slowly followed by carbogen breathing and radiation therapy.

Single-photon emission computed tomography investigations of alternating hemiplegia of childhood

Alterations in regional cerebral blood-flow, as determined by single-photon emission computed tomography (SPECT) using technetium [99mTc] hexamethyl propylenamine oxime, were studied in two children presenting with alternating hemiplegia of childhood. Both experienced hemiplegic episodes several times per month, despite marked improvement on flunarizine therapy. SPECT images of both patients revealed focal areas of decreased uptake of the radiotracer, representing impaired regional cerebral blood-flow during, as well as between, seizures. The interictal finding of localized areas of reduced tracer uptake suggest that long-lasting hypoperfusion could be the pathophysiological mechanism by which the slowly resolving hemiplegia, and ultimately the permanent multifocal neurological deficits, are produced.

[Prophylactic treatment of migraine: a prospective open study on 100 patients]

The prophylactic value of a daily dose of 10 mg flunarizine, a calcium antagonist, was analysed in 100 migraineurs during 4-month in an open study. Ninety-three patients completed the full 16-week course of therapy, and seven patients presented important adverse reactions requiring discontinuation of the drug. However, the seven patients who dropped out during flunarizine treatment were not considered in the analysis. Side-effects included weight gain, sleepiness, humor depression, paresthesias and dry mouth. Eighty-one patients experienced abolition or significant reduction in headache incidence and/or severity. We conclude that flunarizine may be an effective drug in migraine prophylaxis.

Hemodynamic and metabolic effects of flunarizine in experimental subarachnoid hemorrhage in dogs

BACKGROUND AND PURPOSE

Cerebral blood flow and oxygen metabolism were measured and a cerebral angiography was performed in dogs with experimental subarachnoid hemorrhage to assess the relation between arterial narrowing (vasospasm) and the fall of blood flow. Cerebral blood volume and the cerebrovascular CO2 reactivity were also measured to estimate the cerebrovascular reserve. Several groups of dogs were treated with flunarizine in different regimens to assess its possible therapeutic effect.

METHODS

The experiments were performed in the three-hemorrhage canine model for subarachnoid hemorrhage. Cerebral blood flow and cerebral oxygen metabolism were measured in anesthetized (nitrous oxide) dogs using positron emission tomography in combination with the 15O steady-state method. Basilar artery diameter was evaluated by digital subtraction angiography.

RESULTS

In normal dogs, cerebral blood flow, oxygen consumption, and oxygen extraction ratio were 46.4 +/- 9.0 ml/100 ml per minute, 3.65 +/- 0.76 ml/100 ml per minute, and 39.9 +/- 3.4%, respectively; basilar artery diameter was 1.33 +/- 0.25 mm. Repeated subarachnoid blood injection (3 x 5 ml) reduced basilar artery diameter to < 20% of normal (p < 0.01). Cerebral blood flow was reduced by only 25% (p < 0.001); oxygen consumption was preserved at a low normal level by a 29% compensatory increase of the oxygen extraction (p < 0.001). Cerebral blood volume and cerebrovascular CO2 reactivity remained nearly normal. Early (after the first blood injection) peroral treatment with flunarizine (0.5 mg/kg daily) resulted in less severe basilar artery narrowing (56% of normal; p < 0.05 versus untreated). However, this treatment had no effect on cerebral blood flow, blood volume, oxygen consumption, and extraction.

CONCLUSIONS

The observed fall of cerebral blood flow in experimental subarachnoid hemorrhage is not related to arterial narrowing but to an increased cerebrovascular resistance at the level of the small parenchymal vessels, and the latter, in contrast to arterial narrowing, is unaffected by flunarizine.

Hearing recovery in sudden deafness patients using a modified defibrinogenation therapy

Ninety-eight patients with idiopathic sudden deafness were treated with a modified defibrinogenation (DF) therapy including batroxobin, low molecular dextran, vasodilators and vitamins. Hearing improvement was evaluated with two methods: categorical judgement and improvement rate (%). By categorical judgement, 60 patients (61% of the total) were classified into recovery or good improvement categories. The improvement rate was calculated for each of the 93 patients, and the average value was 64%. Modified DF therapy was effective especially for patients with severe hearing loss of 70-90 dB with flat audiogram. Although serum fibrinogen significantly decreased after batroxobin administration there was no correlation between the concentration of fibrinogen and hearing recovery. When prognostic factors were studied, the interval between the onset of hearing loss and start of treatment, initial hearing level, and the existence of vertigo all had significant correlation with the degree of hearing recovery.

Alternating hemiplegia of childhood: a study of 10 patients and results of flunarizine treatment

Alternating hemiplegia of childhood is a rare syndrome characterized by onset before 18 months of age of frequent attacks of alternating paralysis, transient ocular palsies, nystagmus, choreoathetosis, and autonomic dysfunction. We describe features of 10 patients followed for up to 27 years. The mechanism of alternating hemiplegia remains unknown but an association to migraine is suspected because of the strong family history of migraine and aura symptoms in some patients. We treated nine patients with flunarizine, a calcium channel blocker, for up to 5 years; they showed a reduction in duration of the hemiplegic attacks, but the episodes ceased completely in only one patient. With long-term follow-up, the persistent motor, movement, and cognitive deficits are more apparent. It is not certain if the flunarizine alters this course.

Effect of flunarizine and methylprednisolone on functional recovery after experimental spinal injury

The effect of flunarizine and methylprednisolone on the recovery of somatosensory evoked potentials (SEPs) was evaluated in an experimental model of spinal cord impact injury in anesthetized cats. In addition, the effect of flunarizine on posttraumatic spinal cord blood flow (SCBF) (using the hydrogen clearance technique) and interstitial calcium and potassium activity (ion-selective electrodes) was investigated. After the injury (600 g.cm), SEPs disappeared, followed by a spontaneous recovery to 17% of the preinjury amplitude at the end of the 4 h observation period. Flunarizine treatment (0.1 mg/kg IV, given 5 and 120 min after injury) resulted in a significantly improved recovery of SEPs, reaching 52% of the preinjury amplitude. Methylprednisolone treatment (30 mg/kg IV, given 5 min after injury) resulted in a 30% recovery level, significantly better than in untreated animals but significantly inferior to flunarizine treatment. Combination of both treatments resulted in a 62% recovery level, significantly better than after methylprednisolone treatment alone. Flunarizine treatment had no significant effect on the postinjury evolution of SCBF and interstitial potassium activity; it did, however, significantly accelerate the recovery of interstitial calcium activity, which sharply decreased immediately after injury. It is concluded that intravenous administration of the calcium entry blocker flunarizine improves the functional recovery of the spinal cord in the acute phase after experimental spinal impact injury. The observed improvement is not achieved by an effect on local blood flow but is possibly related to an inhibitory effect of the drug on cellular calcium entry.

Amelioration of retinal photic injury by a combination of flunarizine and dimethylthiourea

Free radical scavengers and a calcium overload blocker have been demonstrated separately to ameliorate light-induced retinal degeneration, suggesting that both free radical formation and increased intracellular calcium levels are involved in the pathologic changes of this disease process. To understand the relationship between these two mechanisms, we studied the ameliorative effects of combined treatment with flunarizine and dimethylthiourea as well as individual treatment with either drug in a rat model of light-induced retinal degeneration. At 6 hr and 6 and 14 days after light exposure, morphologic and morphometric studies of the retinas from the rats receiving the combined treatment demonstrated better-preserved retinal pigment epithelial cells, photoreceptor elements, and nuclei than did retinas from rats receiving treatment with either flunarizine or dimethylthiourea alone. Rhodopsin level measurements at 6 and 14 days further substantiated the results of the protective effects on the photoreceptor outer segments. Because we used a saturating dose for dimethylthiourea, the enhanced ameliorative effect of the combination treatment suggested that free radical formation and elevated intracellular calcium levels were two separate mechanisms in light-induced retinal degeneration.

The influence of amitriptyline and flunarizine on catecholamine response to light in patients with migraine

The effect of amitriptyline on catecholamine (CA) response to light of 20 migrainous patients was studied. The drug was given orally, 36 mg daily (12 mg x 3), for ten days. Before therapy, the migraineurs responded to light by an increase in epinephrine (E) excretion and not by the rise in norepinephrine (NE) excretion, noticed in controls. The NE excretion of migrainous subjects underwent very often a depression after photostimulation. Amitriptyline therapy prevented the post-photic rise in E excretion of migraineurs, without influencing significantly the variation in NE excretion produced in them by light. In other 8 migrainous subjects the effect of flunarizine, a selective calcium channel blocker, on CA response to light was tested. The dosage was of 5 mg daily, for ten days. Flunarizine had similar effects to those displayed by amitriptyline; the drug prevented the rise in E excretion produced by light without normalizing the NE response to light of migrainous subjects. The results suggest that the efficiency of these two drugs in migraine prophylaxis is connected with the ability of these substances to block the E discharge produced in migraineurs by light or by other stimuli. The interpretation is all the more likely as propranolol, another drug applied in migraine prophylaxis also blocks the post-photic E discharge of migraineurs.

Radioprotective effects of calcium antagonists used alone or with other types of radioprotectors

Diltiazem, a benzothiazepine calcium channel blocker used widely in cardiovascular therapy, protected mice against death by ionizing radiation. Diltiazem was active in male and female C3H mice and could be administered subcutaneously or intraperitoneally. Protection was also seen in BALB/c, C57Bl/6, and NMRI mice. Moderate activity was afforded by oral administration of effective levels of diltiazem. Injection at 10 or 30 min before irradiation was similarly effective, but injection 2 h prior to the irradiation provided only marginal protection. The dihydropyridine calcium channel blockers nifedipine and nimodipine were also effective, but since these compounds were in an ethanol-containing solvent their radioprotective activity had to be distinguished from that of the ethanol. Synergistic effects occurred by combining diltiazem with zinc aspartate, dimethyl sulfoxide, and nifedipine. Protection by calcium antagonists may be due to interference with the damaging cellular influx of calcium after membrane injury by radiation-induced free radicals or by their direct inactivation. Calcium antagonists could play a role as less toxic radioprotectors, providing modest dose reduction factors but without the prohibitive side effects of aminothiols such as WR-2721.

A syndrome of autosomal dominant alternating hemiplegia: Clinical presentation mimicking intractable epilepsy; chromosomal studies; and physiologic investigations

We report the familial occurrence and apparent autosomal dominant inheritance of alternating hemiplegia of childhood. The proband, a 9-year-old boy, presented with developmental retardation, rare tonic-clonic seizures, and frequent episodes of flaccid alternating hemiplegia that had been presumed to represent postictal paralysis. The hemiplegia spells, which started in his first year, did not respond to multiple antiepileptics. Between attacks, there was choreoathetosis and dystonic posturing. Father, brother, paternal uncle, and paternal grandmother had similar histories of alternating hemiplegia. Investigations included negative CT, metabolic, and coagulation studies. EEG and SPECT 99mTc exametazime scanning failed to reveal any significant slowing or any major changes in cortical perfusion during hemiplegia as compared with nonhemiplegic periods. The karyotype revealed a balanced reciprocal translocation, 46,XY,t(3;9)(p26;q34) in the patient, in all the affected living relatives, and in one apparently unaffected sibling. The asymptomatic mother had a normal karyotype. Analysis of DNA markers was consistent with the karyotype results. Both affected siblings were treated with and responded to flunarizine therapy, with a greater than 70% decrease in attack frequency. Documented flunarizine trough serum concentrations were 28.9 ng/ml in the proband and 6.6 ng/ml in his brother.

[Severe case of basilar migraine treated with flunarizine]

In a man aged 40 years frequent attacks of basilar migraine with consciousness disturbances and signs of central nervous system defects developed due to circulatory failure in the posterior cerebral arteries and cerebellar arteries. The frequency and intensity of migraine attacks decreased only after treatment with flunarizine.

Flunarizine in migraine: a double-blind placebo-controlled study (in a Saudi population)

We evaluated the effect of flunarizine (Fz) (10 mg/d) on migraine in a double-blind placebo-controlled design. The attacks' frequency, duration, severity and associated symptoms were compared before and after treatment. Forty-two patients completed a three-month trial period; 21 patients received Fz and 21 placebo. Statistical analysis showed no significant difference between Fz and placebo (p > 0.05). In this study Fz was not more efficient than placebo in migraine.

Review of pharmacologic treatment of tinnitus

Recent research on the pharmacologic treatment of tinnitus is reviewed, emphasizing studies in which controls have been used. Several double-blind cross-over studies have found that lidocaine can reduce tinnitus in about 50 to 75 percent of subjects. Unfortunately, it cannot be used clinically because it must be administered intravenously and its effects are very brief. Other drugs have been much less successful. A few controlled studies have found success rates between 33 and 56 percent using oxazepam, clonazepam, sodium amylobarbitone, flunarizine, and eperisone hydrochloride. None of these studies have been replicated, however. Closely controlled studies using specified etiologic subgroups with subjective and objective psychophysical measurements are needed.

Alternating hemiplegia in childhood: 23 cases in Japan

Alternating hemiplegia in childhood (AHC) has clinically characteristic features which are easily defined and recognizable. Laboratory investigations were basically normal although they were extensively examined during and between attacks. There is still much debate about its etiology, particularly its relation to migraine or epilepsy. Clinical characteristics of identified 23 AHC in Japanese were presented, which were obtained from a large Japanese cooperative study in 1988. AHC may prove not to be as rare as has been thought.

Comparison of the efficacy and safety of flunarizine to propranolol in the prophylaxis of migraine

This study was designed to compare flunarizine, a cerebro-specific calcium channel antagonist, and propranolol in the prophylaxis of migraine with or without aura. Following a 1 month single-blind placebo baseline period, 94 patients were equitably randomised under double-blind conditions to take flunarizine 10 mg daily or propranolol 80 mg twice daily for 4 months. Both treatments led to a significant reduction in the frequency of migraines and use of rescue analgesics with a significantly greater decrease in number of attacks for flunarizine after 1 and 4 months. Neither treatment affected the severity nor duration of migraines. Overall, 67% of flunarizine patients and 51% of propranolol patients responded positively. Propranolol significantly reduced blood pressure and heart rate; flunarizine had no effect on cardiovascular function. Weight gain was noted with both treatments. Flunarizine is at least as effective as propranolol in the prophylactic treatment of migraine and may have a better safety profile.

Protective effects of flunarizine on ischemic injury in the rat retina

Intracellular calcium overload has been implicated to be a major factor in triggering cell death after ischemic neuronal injury. We investigated the effects of flunarizine hydrochloride, a calcium-overload blocker, on pressure-induced retinal ischemia in a rat model. Retinal ischemia was induced in intraocular pressure to 110 mm Hg for 45 minutes. Two regimens of treatment with flunarizine were examined: (1) prophylactic treatment, in which flunarizine was administered before ischemia and in the early phase of reperfusion; and (2) postischemic treatment, in which flunarizine was administered only in the early phase of reperfusion. Injury was evaluated morphologically and morphometrically by measuring the thickness of the inner retinal layers on plastic-embedded retinal sections and by counting the retinal ganglion cells on retinal flat preparations. By morphologic and morphometric criteria, a significant but partial protection of the inner retinal layers was noted in the groups given either regimen. This protective effect of flunarizine suggests that elevated intracellular calcium concentration may play an important role in ischemic retinal injury.

Flunarizine is effective in prophylaxis of headache associated with scleroderma

Migraine-like headaches may occasionally be seen in patients with scleroderma. The mechanism of these headaches is not well established but may be secondary to central "Raynaud's phenomenon". We report a patient with such headaches that responded dramatically to the centrally acting calcium channel blocker, flunarizine. We suggest that flunarizine should be considered in the management of patients with scleroderma and migraine-like headaches.

[Calcium channel blockers and prevention of migraine]

Calcium antagonists have been proposed for the prophylactic treatment of migraine because of their putative vasodilating antispasmodic effect and of their action against the cellular consequences of brain hypoxia. Published reports of controlled double-blind studies of calcium antagonists for the prophylactic treatment of migraine are reviewed herein. The effectiveness of verapamil, diltiazem, and nifedipine in this indication cannot be considered as firmly demonstrated, when problems with trial design and the amount of available data are taken into account. Nimodipine failed to demonstrate significant effectiveness in migraine with or without an aura. In contrast, the ability of a diphenylpiperazine, flunarizine, to decrease the incidence of migraine attacks in patients with common or classical migraine has been firmly demonstrated, although there is less evidence of this agent's effectiveness on the duration and severity of attacks. The percentage of patients who respond to flunarizine seems comparable to the percentages of propranolol or pizotifen responders. However, flunarizine is associated with unpleasant (weight gain) or severe (extrapyramidal or depressive symptoms) adverse effects which limit its place to that of a second-line drug. Lastly, the analysis of these studies failed to disclose a correlation between calcium movements across the cell membrane and effectiveness for the prevention of migraine attacks. Flunarizine's effect in migraine probably involves monoamine mechanisms which bear no relation to calcium.

Alternating hemiplegia of childhood: case report

We report the case of a 3 1/2 year old girl who had had attacks of alternating hemiplegia from the age of 6 months. Peculiar features from the etiopathogenetic angle seem to be the presence of a ring of mild stenosis of the vertebral artery on the right side, the influence of the upright posture on the onset of the attacks and perhaps also of variations in atmospheric pressure. The only drug that had some effect was flunarizine. Phenobartbital, haloperidol and nadolol had no appreciable effect.

The calcium channel antagonist, flunarizine, protects against ventricular fibrillation

Elevations in intracellular calcium during myocardial ischemia have been implicated in the development of lethal cardiac arrhythmias. The calcium antagonist, flunarizine, has been shown to suppress the accumulation of intracellular calcium and has been proposed to protect against triggered activity due to calcium overload. Using 13 mongrel dogs with healed myocardial infarctions, ventricular fibrillation (VF) was induced by a 2 min coronary occlusion during exercise. This exercise plus ischemia test consistently induced VF during control (C, vehicle) presentations. Pretreatment with flunarizine (2.5 mg/kg i.v.) completely suppressed VF in all the animals (P less than 0.001 Chi-squared). Flunarizine (F) elicited significant (P less than 0.01 ANOVA) reductions in left ventricular (LV) systolic pressure (C 143.2 +/- 12.0 F 92.3 +/- 10.5 mm Hg), LVdP/dt max (C 4256 +/- 251.9, F 1784 +/- 297.2 mm Hg/s) and heart rate (C 118.8 +/- 7.4, F 104.7 +/- 9.0 beats/min). Since heart rate can contribute significantly to the development of VF, the exercise plus ischemia test was repeated with heart rate held constant with ventricular pacing (n = 3, 230.0 +/- 10 beats/min). Flunarizine pretreatment still prevented VF under these conditions.

[Alternating hemiplegia. Partial effectiveness of treatment with flunarizine]

A case of alternating hemiplegia in a young girl is presented. The partial benefits of treatment with a calcium antagonist Flunarizine in this patient and in those reported in literature are reviewed. The onset of the disease in this girl was at three months of age with several episodes that were diagnosed as seizures; afterwards she presented, besides, repeated attacks of hemiplegia involving both sides of her body in an alternating way each time with daily frequency and hours of days of duration accompanied of bad mood and irritability as well as autonomic disturbances, oculomotor abnormalities, acquired mental retardation and residual focal neurological abnormalities. After one year of treatment with a calcium-entry blocker: Flunarizine, there was a 30% reduction in the attacks frequency as well as in its severity and stop of the progression of mental retardation. So we report the consequence of precocious diagnosis and treatment of this not well known entity whose clinical signs resemble paroxistic vascular anomalies in the brainstem territory.

Antitussive effects of Ca2+ channel antagonists

The effects of Ca2+ channel antagonists on the capsaicin-induced cough reflex in guinea pigs were studied. Intraperitoneal injection of nifedipine, verapamil and flunarizine in doses that ranged from 0.3 to 3.0 mg/kg decreased the number of coughs in a dose-dependent manner. These Ca2+ channel antagonists exhibited antitussive effects in the following order of potency: flunarizine = verapamil greater than nifedipine. Pretreatment with a low dose of nifedipine (0.3 mg/kg), which by itself had no significant effect on the number of coughs, markedly increased the antitussive effects of morphine, dihydrocodeine and dextromethorphan. These data suggest that Ca2+ channels play an important role in the regulation of the cough reflex.

Brain SPECT and migraine in childhood

The recent development of SPECT has introduced a new procedure to evaluate neurological diseases. By mean of Tc99mHM-PAO we studied a group of 19 pediatric subjects (7 males and 12 females) with different form of migraine, within five days after the last headache attack. Postictally SPECT shows regionally decreased CBF in 3/4 of HM, in 5/6 of BAM, in 5/5 of CM and in 2/4 of M.

Calcium antagonists suppress experimental allergic neuritis (EAN)

We examined the influence of Ca++ antagonist drugs on immune response and the clinical course of experimental allergic neuritis (EAN). The Ca++ antagonists verapamil and flunarizine suppressed actively induced EAN in Lewis rats in a dose-dependent fashion when given continuously by osmotic pumps from the day of immunization. If given from onset of clinical signs, day 10 after immunization, verapamil alone had therapeutic effects. The beneficial effects of the drugs seem to be mediated primarily by an action on the autoimmune response, since in vitro lymphocyte proliferation in response to nervous tissue antigens was dose-dependently inhibited by both drugs, whereas the in vitro conductivity of demyelinated sciatic nerve was not significantly affected by the Ca++ antagonists. The suppressive effect on lymphocyte proliferation could partially be bypassed by protein kinase C activating phorbol ester alone or in combination with the Ca++ ionophore ionomycin, confirming a non-toxic effect of the Ca++ antagonists on lymphocytes.

Programmed electrical stimulation and drugs identify two subgroups of ventricular tachycardias occurring 16-24 hours after occlusion of the left anterior descending artery

BACKGROUND

Spontaneous sustained ventricular tachycardia (VT) occurring 16-24 hours after left anterior descending (LAD) coronary artery occlusion in the canine heart is most likely based on abnormal automaticity. In vitro, it has been demonstrated that the rate of the arrhythmia and the effect of overdrive pacing depends on the maximal diastolic potential (MDP). The MDP is also of importance in understanding the effect of antiarrhythmic drugs. To study 1) the possible presence of different responses to overdrive pacing and 2) the relation between the response to overdrive pacing and the effect of different antiarrhythmic drugs in the intact heart, we investigated the effect of 1) (prolonged) pacing and 2) lidocaine (3 mg/kg), verapamil (0.4-1.0 mg/kg), or flunarizine (2 mg/kg) during VT.

METHODS AND RESULTS

In 21 conscious dogs with chronic atrioventricular block, 60 sustained VTs were observed 1 day after LAD occlusion. During VT, pacing with interstimulus intervals of 400, 300, and 200 msec for 15, 60, and 120 seconds was done on 40 VTs. Based on their response to pacing, VTs were divided into a pacing-suppressible (PS group) and a pacing-nonsuppressible group (PNS group). The mean cycle length in the PS group was significantly longer (410 +/- 50 msec) than in the PNS group (360 +/- 35 msec, p less than or equal to 0.01). Suppression was directly related to the rate and duration of pacing. Spontaneous recurrence of VTs was observed after 26 +/- 45 seconds. Lidocaine and verapamil increased cycle length of the suppressible VTs and terminated them, whereas flunarizine had no effect. Except for verapamil, which increased cycle length of the VTs, no effects were seen in the PNS group.

CONCLUSIONS

In conscious dogs showing sustained VTs 16-24 hours after LAD occlusion, 1) the slower VTs can be suppressed by pacing, verapamil, and lidocaine but not by flunarizine, and 2) the faster VTs are not affected by pacing, lidocaine, and flunarizine, and are only slowed by verapamil. These findings are compatible with in vitro findings of abnormal automaticity, with the slower VTs originating from a higher MDP than the faster VTs.

Diagnosis and treatment in a case of juvenile subacute necrotizing encephalopathy Leigh without cytochrome c oxidase deficiency

Subacute necrotizing encephalopathy (Leigh syndrome) is characterized by lactacidosis, seizures, ataxia, multiple cerebral hypervascularized lesions and mitochondrial oxidation defects. This is a report on a 21-year-old patient with proven Leigh syndrome, mild central and provokable peripheral lactacidosis, an extra-erythrocyte complex II defect, functionally reduced myokinase adenylate deaminase activity, but no ultrastructural mitochondrial changes. Determination of lactate, pyruvate and ammonia under ischemic conditions plus a pyruvate loading test were particularly useful. Oral flunarizine (Sibelium 30 mg/d) proved to be therapeutically effective.

Long-term results of migraine prophylaxis with flunarizine and beta-blockers

We followed-up 64 migraine patients after discontinuation of successful interval prophylaxis with flunarizine, propranolol or metoprolol, to investigate how long the therapeutic success would last, if further prophylaxis would be successful again, and what factors would influence the prognosis. We found that 16 out of 64 patients experienced a lasting reduction of migraine frequency, whereas 48 patients did improve initially, but later experienced a relapse. Further prophylaxis was effective in 29, poorly effective in 11, and ineffective in 8 of these patients; in 7 of the 8 non-responders prophylaxis was not changed. Negative prognostic factors were frequent attacks, a history of analgesic abuse and/or analgesic withdrawal therapy and ineffective previous prophylaxis. In conclusion, the therapeutic success decreases dramatically in the majority of patients several months after discontinuation of prophylaxis; further prophylaxis is more effective if the substance class is changed; increased analgesic intake is the most important prognostic factor. As a strategy for migraine prophylaxis we propose sequential changing of interval prophylaxis or--in patients with negative prognostic factors--long-term prophylaxis.

Flunarizine versus metoprolol in migraine prophylaxis: a double-blind, randomized parallel group study of efficacy and tolerability

The prophylactic effect of flunarizine and metoprolol was studied in a multi-center randomized, double-blind trial of 149 patients with migraine with or without aura. After a 4-week placebo run-in period, patients were randomly allocated to treatment with flunarizine 10 mg daily or metoprolol 200 mg daily for 16 weeks (parallel group design). Both drugs reduced the number of migraine days per month by 37% (95% confidence interval 21-53%) compared with the placebo run-in period. All efficacy parameters were significantly reduced by both drugs and no significant difference was found between the two drugs at any time of the treatment period. However, calculation of the 95% confidence limits showed that each drug may have a superiority of more than 100% on a single main effect parameter. The most common adverse experiences were day-time sedation (both drugs) and weight gain (flunarizine). Depression was the most serious side-effect occurring in 8% on flunarizine and 3% on metoprolol. We conclude that both drugs are effective in the prevention of migraine attacks but a higher number of dropouts occurred on flunarizine because of depression or weight gain.

[Trial of amitriptyline versus flunarizine as treatment of vestibular diseases. A preliminary study]

109 patients with vestibular disease were included in two different treatments with amitriptyline (Group A:53 patients with depressive symptoms), or flunarizine (Group B: 56 patients). Vertiginous symptoms, basic vestibular exploration, depressive disorder, cochlear symptoms, vegetative disorders and headache were evaluated. Among the patients treated with amitriptyline a significant decrease in the vertiginous symptoms were observed. The possible mechanism of action were analyzed too.

Flunarizine in migraine prophylaxis: an Indian trial

Flunarizine, a calcium channel blocker is considered useful in migraine prophylaxis. We report the first Indian trial with this drug. Fifteen patients with migraine were studied in a 6 months double-blind, placebo-controlled crossover trial. Flunarizine was superior to placebo in reducing the severity and duration of the individual attacks though there was no statistically significant effect on frequency of migraine attacks. The side effects most frequently caused by flunarizine were weight gain and daytime sleepiness.

Synthesis and biological activity of 11-[4-(cinnamyl)-1-piperazinyl]- 6,11-dihydrodibenz[b,e]oxepin derivatives, potential agents for the treatment of cerebrovascular disorders

A series of 11-[4-(cinnamyl)-1-piperazinyl]-6,11-dihydrodibenz[b,e] oxepins and related compounds were synthesized and evaluated for their protective activities against complete ischemia, normobaric hypoxia, lipidperoxidation and convulsion. Structure-activity relationship studies of this series led to the finding of (E)-1-(3-fluoro-6,11-dihydrodibenz[b,e]oxepin-11-yl)-4-(3- phenyl-2-propenyl)piperazine dimaleate (50), AJ-3941 with the most appropriate property for combined pharmacological activities. Compound 50 also shows an inhibitory effect against cerebral edema as well when orally given to rats.

Idiopathic headache as a possible risk factor for phantom tooth pain

Following tooth pulp extirpation, some subjects suffer from persistent pain which affects edentate sites in absence of any local pathology. As regards this peculiar pain, called phantom tooth pain (PTP), what is puzzling is the fact there is a low prevalence of PTP in a very large population showing identical conditions of tooth pulp extirpation. The present investigation indicates that PTP mainly affects migraine (M) and cluster headache (CH) sufferers, whereas it does not affect subjects who have a negative personal and family history for idiopathic headache (IH). These results circumscribe the presence of PTP to a specific section of the population. The present results, besides indicating that PTP may be the result of a peculiar neuronal predisposition relating to IH pathogenesis, suggests some practical therapeutic hints. In fact, successful anti- M and anti-CH prophylactic treatment greatly improve PTP syndrome.

Double-blind placebo-controlled trial of flunarizine as add-on therapy in refractory childhood epilepsy

Flunarizine (FLN) has been suggested as an add-on treatment in drug-resistant epilepsy patients. In view of the discordant experiences and of the paucity of controlled trials in children, we studied its effectiveness in 20 patients aged 6 to 18 years (10 males and 10 females), affected by drug-resistant epilepsy. 14 had symptomatic generalized epilepsy (the Lennox-Gastaut syndrome in 10; other forms in 4); 3 had cryptogenic generalized epilepsy (the Lennox-Gastaut syndrome in 2; myoclonic absences epilepsy in 1); 3 had symptomatic partial epilepsy (temporal lobe epilepsy). 7 of them were withdrawn: only 1 because of side effects. An initial four-month baseline pretrial period was followed by two four-month periods of administration of FLN or a placebo, under double blind conditions, in a randomized sequence. Preexisting antiepileptic (AEDs) medication was maintained at a constant dose throughout the study. FLN was administered as drops in a single evening dose of 5 mg (patients less than 10 years) or 10 mg. (patients greater than 10 years). During the pretrial phase, after phase 1 and phase 2, a waking EEG was recorded and blood samples were taken for hematology, hepatic-function tests, and AED serum levels. The evaluation of the activity of FLN was based on the total number of seizures. A 30-60% reduction in seizure frequency was found in 5 out of the 13 patients completing the trial (no changes occurred in the remainders). This result did not appear to be due to changes in the plasma levels of the AEDs. No significant differences were seen in the EEG paroxysmal activity in the three phases of the study. Side effects were rare. The serum FLN levels ranged between 16.4 and 109 ng/ml. It seems that the antiepileptic properties of FLN need further validation, particularly in childhood.

Flunarizine in migraine: a minireview

Flunarizine is a non-selective calcium antagonist. It distributes preferentially in the adipose tissue and passes the blood brain barrier. Numerous controlled clinical studies have established that flunarizine is efficacious in migraine prophylaxis, including double-blind studies in which the drug was compared with placebo or other antimigraine drugs. To avoid side effects a special schedule or administration is necessary. Flunarizine has no myogenic effect on smooth muscle cells of the vessles. It is said to be the only calcium antagonist able to protect brain cells against hypoxic damage. In addition, the considerable body of information which shows flunarizine capable of directly influencing the central nervous system, suggests that the drug's anti-migraine action may depend on its ability to influence central phenomena.

[Raynaud's phenomenon and calcium blocking agents. A preliminary open study with flunarizine]

Raynaud's phenomenon (Raynaud's disease), an accessual vascular acrosyndrome characterised by an important constriction of distal arterioles, has still no specific pharmacological therapy. In the last years, the use of calcium-entry-blockers (nifedipine, diltiazem, verapamil, nicardipine), drugs able to control the contractility of the vessels, showed some positive results. Considering this data, we appraised the efficacy of flunarizine, another calcium-entry-blocker, in a preliminary study of 28 patients (23 females, 5 males, aged between 15 and 48 years) suffering from Raynaud's disease. Apart from a statistically insignificant improvement of subjective symptoms (i.e. acroparesthesias, cold extremities) flunarizine (10 mg/day for 1 month) did not have positive results. Finally, this drug caused some side-effects: drowsiness, increase of weight and appetite, but without a real necessity for withdrawal of therapy.

rCBF-SPECT in brain infarction: when does it predict outcome?

We prospectively studied 26 patients with ischemic stroke within 24 hr, after 2 wk, and after 6 mo with thallium-201-diethyldithiocarbamate single-photon emission computed tomography (SPECT) and neurologic and functional assessments. The admission flow deficits correlated with outcome. The admission and 6-mo scores correlated with clinical conditions at each time. At 2 wk, the flow deficits were smaller and did not correlate with clinical parameters. Nor did the presence or absence of hyperfixation of the radiopharmaceutical. Six months after the infarct, the flow defect had decreased in 9 of 15 patients in whom three serial scans were available, with better clinical improvement than in the remaining six whose flow deficits increased. More patients in the first group had been treated randomly with the calcium-entry blocker flunarizine. SPECT imaging of rCBF within 24 hr after stroke correlates with clinical outcome and condition, whereas rCBF imaging at 2 wk after the stroke shows no clinical correlation.

Infrarenal aortic occlusion in the rabbit to assess the effect of flunarizine in the prevention of ischemic spinal cord injury

Infrarenal aortic occlusion in rabbits to produce paraplegia is possible in large series and can be achieved without any side-effects of anesthetic drugs. This model was tested for its suitability to investigate the use of calcium-channel blockers, which potentially reduce or prevent ischemic spinal cord damage. In a pilot study 26 rabbits were treated with 0.1 mg/kg Flunarizine i.v. prior to occlusion and 38 animals served as control. Groups were compared where the aorta was occluded for 10, 15, 20, 25 or 30 min. No reduction of paraplegia in the Flunarizine groups was observed, apart from in the 15-min occlusion subset: here the number of unaffected animals was significantly greater (p less than 0.05). At histopathological examination the number of ischemic spinal cord segments was reduced (p less than 0.03). It is concluded that Flunarizine could not reduce the cellular damage of the spinal-cord due to complete and global ischemia after an aortic occlusion interval exceeding 15 min. The narrow interval between potential recovery (15 min) and definite paraplegia (20 min) makes this rabbit paraplegia model less appropriate for testing of calcium-channel blockers which are presumed to have a moderate effect on the reduction of spinal cord ischemia.

[Pharmacokinetics and pharmacodynamics of flunarizine in multimorbid, geriatric patients with vertigo]

Ten multimorbid, geriatric, hospitalised patients, mean age 76 years, were treated for vertigo and received 10 mg flunarizine (CAS 52468-60-7; Sibelium) daily for 3 weeks. The study of the pharmacokinetics and pharmacodynamics of this dosage scheme revealed that the kinetics did not change during the three weeks of therapy. The terminal half-life is 7.3 +/- 3.3 days. Since a steady state concentration is only to be expected after about 5 half-lives, this condition was not fully met yet in most patients after three weeks. The data obtained from the patients examined are essentially identical with those in young and old healthy subjects. The unchanged kinetics during long-term treatment prevent side-effects due to cumulation on the one hand or the decrease of plasma levels to inactive concentrations resulting from enzyme induction. There was not measurable anti-aggregator effect on thrombocytes or erythrocytes. The effectiveness in connection with vertigo seems to be due to a direct labyrinth depressor activity and/or to a selective vasospecific action. No side-effects were observed during the three weeks of therapy.

Comparison of the calcium entry blockers nimodipine and flunarizine on human cerebral and temporal arteries: role in cerebrovascular disorders

The effect of the calcium entry blockers flunarizine and nimodipine on isolated human cerebral and temporal arteries has been studied. Flunarizine induced only weak relaxation of precontracted temporal arteries in contrast to the response seen in cerebral arteries. Nimodipine invariably induced strong relaxation of both types of vessel. The effect of the calcium entry blockers on potassium (K+)-, noradrenaline (NA)- and 5-hydroxytryptamine (5-HT)-induced contraction was also examined. In general, the K(+)-induced contraction was inhibited by both calcium entry blockers, nimodipine being more potent than flunarizine, the cerebral artery being more sensitive. The response to K+ consisted of two phases; the second, slowly developing phase of contraction was more sensitive to either blocker than the initial, fast phase of contraction. Flunarizine was significantly more potent in inhibiting NA-induced contraction of the human cerebral than of the temporal artery, and there was no difference in its action on 5-HT-induced contraction of either artery. The same pattern was found for nimodipine, which was more potent in every aspect. Both calcium entry blockers induced a parallel shift in calcium-induced contraction studied by application of calcium to vessels preincubated in calcium free medium. Flunarizine was more potent on cerebral than on temporal arteries and there was no difference between the two vessels in this action of nimodipine. However, the latter was more potent than flunarizine in preventing calcium-induced contraction. The clinical implications of the two agents are discussed in relation to cerebrovascular disorders.

Idiopathic arterial calcification of infancy

We describe two twin sisters in whom calcification of different arteries was detected in the first weeks of life. Transient renal insufficiency, arterial hypertension, and skeletal abnormalities were also observed. One child had anasarca and heart decompensation at birth. Prenatal infarction of one kidney had occurred in the same infant. A kidney biopsy showed calcium deposits in all the layers of the arteries. Most findings in these patients are compatible with idiopathic arterial calcification of infancy (IACI). Investigation of calcium and phosphorus metabolism revealed spontaneously receding hypercalciuria, increased intraerythrocytic calcium levels, and transient X-ray abnormalities of the long bones. Treatment initially consisted of biphosphonate and later, the calcium antagonist flunarizin. A progressive diminution of the arterial calcification was observed in the course of both treatments.

Flunarizine, a calcium channel antagonist, is not neuroprotective when given after hypoxia-ischemia in the infant rat

21-day-old rats were subjected to unilateral carotid ligation, then, after 2 h of recovery, to 2 h of 8% hypoxia. Immediately following the insult they were treated with either flunarizine (30 mg/kg, i.p.) or with an equal volume of diluent. We have previously shown similar doses of flunarizine to be neuroprotective when given preinsult. After 5 days they were sacrificed for histological analysis. Cerebral injury was almost entirely confined to the ligated side. Full-thickness cortical infarction was noted in 55% of controls (n = 29) versus 36% of flunarizine-treated rats (n = 28; p = 0.14). Mean damage scores for all areas assessed including cortex, striatum, and hippocampus were not significantly different. These observations suggest that flunarizine is not significantly neuroprotective when given immediately after severe hypoxia-ischemia.

Comparative neuroprotective effects of pentobarbital, vinpocetine, flunarizine and ifenprodil on ischemic neuronal damage in the gerbil hippocampus

We studied the protective effects of pentobarbital, vinpocetine, flunarizine, and ifenprodil on delayed neuronal death using Mongolian gerbils. The animals were allowed to survive for 7 days after 5 min of cerebral ischemia induced by bilateral occlusion of the common carotid arteries. Hippocampal cell loss was quantified histologically 7 days following ischemia. Intraperitoneal application of pentobarbital (40 mg/kg) 30 min and vinpocetine (50 and 100 mg/kg) 10 min before ischemia significantly reduced neuronal cell loss in the CA1 sector. However, the intraperitoneal administration of flunarizine (10 and 30 mg/kg) and ifenprodil (10 and 30 mg/kg) 15 min before ischemia was not protective. The results suggest that pentobarbital and vinpocetine prevent ischemic neuronal damage, but not flunarizine and ifenprodil. These findings are of interest in relation to the mechanism of delayed neuronal death.

[The treatment of juvenile migraine using flunarizine or propranolol]

The clinical efficacy of flunarizine and propranolol for the prevention of migraine attacks was assessed in 33 children in a double blind study. After a run-in phase of one month, 32 patients started the active medication. A reduction in the number of migraine attacks was observed in 75% of the flunarizine group and in 73.8% of the propranolol group. Propranolol also reduced the severity of attacks. Transient side effects were observed in 3 of 17 of the flunarizine group and in 5 of 15 of the propranolol group. The most frequent side effect was increased fatigue, which required interruption of therapy in 2 patients of the propranolol group.

Significance of thromboxane A2 and prostaglandin I2 in acute necrotizing pancreatitis in rats

Plasma thromboxane concentrations were found to be significantly elevated in acute necrotizing pancreatitis in rats, whereas prostaglandin I2 levels were not. The significance of these alterations was investigated. Pancreatitis was induced by injecting 5% sodium taurocholate into the pancreatic duct. Iloprost (ZK 36374, a stable analog of prostaglandin I2, 25 ng/kg body weight) decreased the mortality rate from 100% to 50%. When treatment with iloprost was combined with simultaneous administration of either Sibelium (flunarizine R 14,950, 0.2 mg/kg body weight) or dazmegrel (UK 38,485, 50 mg/kg body weight) an additional decrease in the mortality rate was recorded. Dazmegrel is a selective thromboxane A2 synthetase inhibitor and flunarizine (a calcium entry blocker) also inhibits the effects of elevated thromboxane A2 levels. With flunarizine and iloprost the mortality rate was 40% (P less than 0.05); with dazmegrel and iloprost it was 10% (P less than 0.01). The results of the present study suggest that thromboxane A2 and prostaglandin I2 play a role in the course of acute necrotizing pancreatitis.