The difference between non-selective and beta 1-selective beta-blockers in their effect on platelet function in migraine patients

The history and rationale of the development of new drugs for migraine treatment

Migraine is one of the most prevalent and disabling diseases in the world. Migraine attack treatments and prophylactic treatments of this disease are essential to lessen its individual, social, and economic impact. This is a narrative review of the main drugs used for treating migraine, as well as the experimental models and the theoretical frameworks that led to their development. Ergot derivatives, triptans, non-steroid anti-inflammatory drugs, tricyclic antidepressants, beta-blockers,: flunarizine,: valproic acid,: topiramate, onabotulinumtoxin A, ditans, monoclonal antibodies against CGRP and its receptor, and gepants are discussed. Possible therapeutic targets for the development of new drugs that are under development are also addressed. Many of the drugs currently in use for treating migraine were developed for the treatment of other diseases, but have proven effective for the treatment of migraine, expanding knowledge about the disease. With a better understanding of the pathophysiology of migraine, new drugs have been and continue to be developed specifically for the treatment of this disease.

Beta-blockers for the prevention of headache in adults, a systematic review and meta-analysis

BACKGROUND

Headaches are a common source of pain and suffering. The study's purpose was to assess beta-blockers efficacy in preventing migraine and tension-type headache.

METHODS

Cochrane Register of Controlled Trials; MEDLINE; EMBASE; ISI Web of Science, clinical trial registries, CNKI, Wanfang and CQVIP were searched through 21 August 2018, for randomized trials in which at least one comparison was a beta-blocker for the prevention of migraine or tension-type headache in adults. The primary outcome, headache frequency per month, was extracted in duplicate and pooled using random effects models.

DATA SYNTHESIS

This study included 108 randomized controlled trials, 50 placebo-controlled and 58 comparative effectiveness trials. Compared to placebo, propranolol reduced episodic migraine headaches by 1.5 headaches/month at 8 weeks (95% CI: -2.3 to -0.65) and was more likely to reduce headaches by 50% (RR: 1.4, 95% CI: 1.1-1.7). Trial Sequential Analysis (TSA) found that these outcomes were unlikely to be due to a Type I error. A network analysis suggested that beta-blocker's benefit for episodic migraines may be a class effect. Trials comparing beta-blockers to other interventions were largely single, underpowered trials. Propranolol was comparable to other medications known to be effective including flunarizine, topiramate and valproate. For chronic migraine, propranolol was more likely to reduce headaches by at least 50% (RR: 2.0, 95% CI: 1.0-4.3). There was only one trial of beta-blockers for tension-type headache.

CONCLUSIONS

There is high quality evidence that propranolol is better than placebo for episodic migraine headache. Other comparisons were underpowered, rated as low-quality based on only including single trials, making definitive conclusions about comparative effectiveness impossible. There were few trials examining beta-blocker effectiveness for chronic migraine or tension-type headache though there was limited evidence of benefit.

REGISTRATION

Prospero (ID: CRD42017050335).

WITHDRAWN: Propranolol for migraine prophylaxis

BACKGROUND

Propranolol is one of the most commonly prescribed drugs for migraine prophylaxis.

OBJECTIVES

We aimed to determine whether there is evidence that propranolol is more effective than placebo and as effective as other drugs for the interval (prophylactic) treatment of patients with migraine.

SEARCH METHODS

Potentially eligible studies were identified by searching MEDLINE/PubMed (1966 to May 2003) and the Cochrane Central Register of Controlled Trials (Issue 2, 2003), and by screening bibliographies of reviews and identified articles.

SELECTION CRITERIA

We included randomised and quasi-randomised clinical trials of at least 4 weeks duration comparing clinical effects of propranolol with placebo or another drug in adult migraine sufferers.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted information on patients, methods, interventions, outcomes measured, and results using a pre-tested form. Study quality was assessed using two checklists (Jadad scale and Delphi list). Due to the heterogeneity of outcome measures and insufficient reporting of the data, only selective quantitative meta-analyses were performed. As far as possible, effect size estimates were calculated for single trials. In addition, results were summarised descriptively and by a vote count among the reviewers.

MAIN RESULTS

A total of 58 trials with 5072 participants met the inclusion criteria. The 58 selected trials included 26 comparisons with placebo and 47 comparisons with other drugs. The methodological quality of the majority of trials was unsatisfactory. The principal shortcomings were high dropout rates and insufficient reporting and handling of this problem in the analysis. Overall, the 26 placebo-controlled trials showed clear short-term effects of propranolol over placebo. Due to the lack of studies with long-term follow up, it is unclear whether these effects are stable after stopping propranolol. The 47 comparisons with calcium antagonists, other beta-blockers, and a variety of other drugs did not yield any clear-cut differences. Sample size was, however, insufficient in most trials to establish equivalence.

AUTHORS' CONCLUSIONS

Although many trials have relevant methodological shortcomings, there is clear evidence that propranolol is more effective than placebo in the short-term interval treatment of migraine. Evidence on long-term effects is lacking. Propranolol seems to be as effective and safe as a variety of other drugs used for migraine prophylaxis.

Is the effect of antihypertensive drugs on platelet aggregability and fibrinolysis clinically relevant?

Hypertension is associated with decreased fibrinolytic potential, mainly expressed as elevated plasma plasminogen activator inhibitor type 1 (PAI-1) levels, and increased platelet aggregability, which may account in part for the increased risk of atherosclerosis and its clinical complications in hypertensive patients. The effects of antihypertensive drugs on this prothrombotic state have been investigated and controversial findings have been reported, possibly because of differences in study designs, patients selected, and methodology used. Scarce and conflicting data exist about the effects of diuretics and beta-adrenoceptor antagonists on the fibrinolytic system, whereas ACE inhibitors have generally been reported to improve the fibrinolytic balance by decreasing plasma PAI-1 levels, calcium channel antagonists have been shown to increase tissue plasminogen activator (tPA) activity, and angiotensin II type 1 (AT(1)) receptor antagonists seem to exert neutral effects. beta-Adrenoceptor antagonists, calcium channel antagonists, and AT(1)-receptor antagonists have been reported to exert anti-aggregatory effects on platelets, while contrasting data exist about the influence of ACE inhibitors. Clinical implications of the changes induced by antihypertensive drugs on the fibrinolytic balance and platelet function are still debated. In particular, the question of whether these changes may translate into different degrees of cardiovascular protection in hypertensive patients remains unanswered. While awaiting more information from clinical trials, the choice of antihypertensive drugs, particularly in high-risk patients, should take into account effects beyond their BP-lowering efficacy. Selected agents should have a favorable, or at least neutral, impact on fibrinolytic function and platelet activity.

Propranolol for migraine prophylaxis

BACKGROUND

Propranolol is one of the most commonly prescribed drugs for migraine prophylaxis.

OBJECTIVES

We aimed to determine whether there is evidence that propranolol is more effective than placebo and as effective as other drugs for the interval (prophylactic) treatment of patients with migraine.

SEARCH STRATEGY

Potentially eligible studies were identified by searching MEDLINE/PubMed (1966 to May 2003) and the Cochrane Central Register of Controlled Trials (Issue 2, 2003), and by screening bibliographies of reviews and identified articles.

SELECTION CRITERIA

We included randomised and quasi-randomised clinical trials of at least 4 weeks duration comparing clinical effects of propranolol with placebo or another drug in adult migraine sufferers.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted information on patients, methods, interventions, outcomes measured, and results using a pre-tested form. Study quality was assessed using two checklists (Jadad scale and Delphi list). Due to the heterogeneity of outcome measures and insufficient reporting of the data, only selective quantitative meta-analyses were performed. As far as possible, effect size estimates were calculated for single trials. In addition, results were summarised descriptively and by a vote count among the reviewers.

MAIN RESULTS

A total of 58 trials with 5072 participants met the inclusion criteria. The 58 selected trials included 26 comparisons with placebo and 47 comparisons with other drugs. The methodological quality of the majority of trials was unsatisfactory. The principal shortcomings were high dropout rates and insufficient reporting and handling of this problem in the analysis. Overall, the 26 placebo-controlled trials showed clear short-term effects of propranolol over placebo. Due to the lack of studies with long-term follow up, it is unclear whether these effects are stable after stopping propranolol. The 47 comparisons with calcium antagonists, other beta-blockers, and a variety of other drugs did not yield any clear-cut differences. Sample size was, however, insufficient in most trials to establish equivalence.

REVIEWERS' CONCLUSIONS

Although many trials have relevant methodological shortcomings, there is clear evidence that propranolol is more effective than placebo in the short-term interval treatment of migraine. Evidence on long-term effects is lacking. Propranolol seems to be as effective and safe as a variety of other drugs used for migraine prophylaxis.

Platelet P1, P4-Di (adenosine-51) tetraphosphate (AP4A) in migraine patients before and during beta-adrenoceptor blockade

P1,P4-Di(adenosine-51) tetraphosphate (AP4A) is a metabolically inactive nucleotide which can be released from platelet dense granules. This study was designed firstly, to investigate whether platelet content of AP4A was decreased in patients with classical migraine and secondly, whether the content of AP4A was changed by beta-adrenoceptor blockade. No significant difference in platelet dense granule content of AP4A, was observed between 10 migraine patients and 10 normal controls. Both metoprolol, a beta 1-selective blocker and propranolol, a non-selective beta-blocker significantly decreased the migraine attack rate. However, while propranolol significantly reduced the platelet content of AP4A, metoprolol did not. Therefore, the present data suggest that platelet dense granule release, as estimated by the content of AP4A is not of major importance in migraine.

Platelet function in classic migraine during attack-free periods

It has been reported that migraine sufferers have an enhanced platelet activity, as well as an enhanced thromboembolic risk. In this study, 12 subjects with classic migraine were compared with 12 age- and sex-matched controls. The following parameters were tested: platelet aggregation; platelet content of ADP, ATP and cyclic-AMP (cAMP); plasma levels of cAMP, 6-keto-PGF1 alpha and thromboxane B2, serum levels of TxB2 and lipids. ADP- and adrenaline-induced platelet aggregation, platelet content of ADP, ATP and cAMP did not differ significantly between the groups. Platelets from migraine subjects, however, showed a decreased beta-adrenoceptor response to stimulation with isoprenaline when determined as platelet cAMP production in vitro. The prostacyclin metabolite 6-keto-PGF 1 alpha was significantly decreased in the migraine group. No difference were observed in TxB2. Plasma lipids were similar, except that the migraine cases had higher levels of LDL-cholesterol. These data do not confirm a general platelet malfunction in migraine patients, but suggest a decreased functional capacity of platelet beta-adrenoceptors and an altered metabolism of prostacyclin and LDL-cholesterol.

The effect of exercise on platelet beta-adrenoceptor function and platelet aggregation in healthy human volunteers

Plasma levels of adrenaline and noradrenaline, platelet cyclic-AMP (cAMP) content, platelet aggregation, platelet release of beta-thromboglobulin, and platelet factor 4 and serum content of thromboxane B2(TXB2) and 6-keto-PGF1 alpha were measured in 12 healthy male volunteers (age 38-72, mean 54.2 years) who were tested at rest and immediately after five min light cycle exercise. The plasma levels of adrenaline and noradrenaline increased significantly after exercise (P less than 0.01). The platelet cAMP level was not changed by exercise. The functional capacity of platelet beta-adrenoceptors, determined as cAMP production after beta-adrenoceptor stimulation in vitro, decreased highly significantly after exercise in all 12 volunteers (P less than 0.01). No alteration was observed in platelet aggregation induced by adrenaline or in platelet release of beta-thromboglobulin or platelet factor 4. No change was observed in the serum levels of TXB2 and 6-keto-PGF1 alpha.

IN CONCLUSION

light cycle exercise results in a decreased functional capacity of platelet beta-adrenoceptors, but has no effect on platelet aggregation or platelet release. This might indicate a concomitant and equal decreased functional capacity of platelet alpha-adrenoceptors.

Differential effects of timolol and metoprolol on platelet function at rest and during exercise

Ten male patients suffering from stable angina pectoris were studied at rest and immediately after exercise during treatment either with timolol (a non-selective beta-blocker) or with metoprolol (a beta 1-selective blocker). Timolol induced a significant increase in platelet aggregation and a reduction in platelet cyclic AMP, and it also raised the plasma adrenaline at rest and during exercise as compared to the pre-treatment level. Metoprolol had none of these effects. Prior to medication and during metoprolol treatment, exercise led to an increase in the peripheral platelet count, whereas timolol was associated with a reduction of platelets during physical effort. Neither drug affected platelet thromboxane B2 at rest. During exercise, its level was not affected in the pre-treatment period or during metoprolol treatment but it was sharply increased by timolol therapy.