Effect of naratriptan on myocardial blood flow and coronary vasodilator reserve in migraineurs

Therapeutic Options for Migraines in the Microsurgical Patient: A Scoping Review

BACKGROUND

There exists an increasing array of treatments proposed to prevent, alleviate, and abort symptoms of a migraine; however, for patients who undergo reconstructive microsurgery, caution must be taken to preserve vascular integrity. This study is the first-to-date scoping review of vascular and bleeding risk of current migraine therapies, with the purpose of identifying potential therapeutic agents for postoperative migraine management appropriate for microsurgical patients.

METHODS

Currently available migraine therapeutics were compiled from the UpToDate software system and the American Academy of Family Physicians. A PubMed literature review was performed for each therapeutic's effect on bleeding or vascular involvement. Data were compiled into tables of abortive, symptom-controlling and prophylactic, and nonpharmacologic treatments. Expert microsurgeons reviewed the data to provide recommendations for optimized patient care.

RESULTS

Triptans and other ergot derivatives demonstrated strong evidence of vasoconstriction and were greatly advised against for immediate postmicrosurgical use. Novel pharmaceutical therapies such as lasmiditan and calcitonin gene-related peptide antagonists have no literature indicating potential for vasoconstriction or hematoma and remain an investigational option for abortive medical treatment. For symptom control, acetaminophen appears the safest option, with clinical judgment and further research needed for use of nonsteroidal antiinflammatory drugs. Alternative treatment techniques may include migraine prophylaxis with botulinum toxin injection or nutraceutical treatment by means of magnesium supplementation or coenzyme Q10 administration, minimizing the need for additional medication in the postoperative setting.

CONCLUSIONS

Patients undergoing reconstructive microsurgery have a unique medical profile limiting the therapeutic options available to treat migraines. This review provides preliminary evidence to be considered as a guide for prescribing therapeutics for migraine in the postoperative setting.

Managing Migraines: Options for Acute Abortive Treatment

Introduction

Triptans, ergotamine derivatives and nonsteroidal anti-inflammatory drugs are front-line agents used in the acute abortive therapy of migraines. In this article, these medications are reviewed and a treatment algorithm suggested.

Methods

A comprehensive review of the literature from 1990 to 2008 was conducted using PubMed, MEDLINE and The Cochrane Library to explore the underlying pathophysiology of migraines and comparatively assess the acute and chronic treatment options available in their management. The information obtained from all literature searches was further categorized as level 1, 2 or 3 based on pre-defined peer-reviewed criteria.

Conclusion:

This review is able to present a relatively preliminary but practical migraine treatment algorithm. Although there is no standard universal treatment strategy to manage migraine headaches in all patients, this review has been put forth to serve as a clinical guideline to assist health professionals in deciding the most appropriate treatment for migraine headaches.

Effects of sumatriptan and eletriptan on diseased epicardial coronary arteries

BACKGROUND

Triptans are contraindicated in patients with known or suspected coronary artery disease (CAD); however, few studies have evaluated triptans in patients with obstructive CAD to quantify the vasoconstrictive effect on diseased coronary vessels.

METHODS

Patients undergoing percutaneous transluminal coronary angioplasty for symptomatic single-vessel CAD were randomised to one of three parallel cohorts to receive (1) 6 mg intravenously (IV) infused eletriptan plus subcutaneous (SC) placebo, (2) IV infused placebo plus 6 mg SC sumatriptan or (3) IV infused placebo plus SC placebo, as simultaneous administrations in a double-blind manner. Serial arteriograms, hemodynamic indices, electrocardiography and triptan plasma concentrations were obtained.

RESULTS

. Fifteen minutes after triptan challenge, median (95% confidence interval) changes in coronary artery diameter (CADM) at the focal point of the stenosed segment were: dilation of 2.6% (-5.0, 11.4), eletriptan 6 mg IV (n = 18); constriction of 6.8% (-12.6, 0.4), sumatriptan 6 mg SC (n = 17), and constriction of 4.5% (-7.0, 7.9), placebo (n = 10). One patient had angiographic evidence of a new thrombus at the stenosis site, necessitating termination of study infusion and successful stenting of the lesion. There was no correlation between effects on CADM and triptan concentration, or between hemodynamic or electrocardiograph changes and the presence (n = 13) or absence (n = 33) of chest pain.

CONCLUSIONS

Triptans had very little effect on diseased epicardial coronary arteries in a small group of angina sufferers with established CAD. Results should be interpreted cautiously since there may be instances where even modest triptan-associated epicardial constriction is sufficient to precipitate myocardial ischemia in patients with severe obstructive CAD.

Evaluating the safety and tolerability profile of acute treatments for migraine

Among the medications that have been used as acute treatments for migraine are nonspecific agents, including nonsteroidal anti-inflammatory drugs (NSAIDs), analgesics (either single or combination), and narcotics, as well as migraine-specific medications, including ergot alkaloids and triptans (5-hydroxytryptamine 1B/1D agonists). All of these drugs have side effects that vary in type and severity. Side effects of nonspecific medications, including gastrointestinal (GI) and renal effects with NSAIDs and cognitive effects and the potential for abuse with narcotics and butalbital-containing medications, have been documented over time, as these medications have been used for various indications. Side effects of the migraine-specific medications include GI and vascular symptoms with the ergots; for the triptans, they include chest and neurologic symptoms. Although adverse events are reported fairly frequently in patients receiving triptans, they are usually mild, and few patients discontinue therapy because of them. The most serious adverse events are cardiovascular. Because of potential vasoconstrictor effects--mild and transient increases in blood pressure and mild and transient effects on coronary artery tone--triptans as a class are contraindicated in patients with established or clinically suspected cardiovascular disease, specifically ischemic heart disease and uncontrolled hypertension. Other adverse events, including the potential for drug-drug interactions, are less common. Therefore, consideration should be given to the tolerability and safety of medications before their use as abortive medications for the treatment of migraine headache.

Preclinical neuropharmacology of naratriptan

The basic CNS neuropharmacology of naratriptan is reviewed here. Naratriptan is a second-generation triptan antimigraine drug, developed at a time when CNS activity was thought not to be relevant to its therapeutic effect in migraine. It was, however, developed to be a more lipid-soluble, more readily absorbed and less readily metabolized variant on preexisting triptans and these variations conferred on it a higher CNS profile. Naratriptan is a 5-HT(1B/1D) receptor agonist with a highly selective action on migraine pain and nausea, without significant effect on other pain or even other trigeminal pain. Probable sites of therapeutic action of naratriptan include any or all of: the cranial vasculature; the peripheral terminations of trigeminovascular sensory nerves; the first-order synapses of the trigeminovascular sensory system; the descending pain control system; and the nuclei of the thalamus. Naratriptan may prevent painful dilatation of intracranial vessels or reverse such painful dilatation. Naratriptan can prevent the release of sensory peptides and inhibit painful neurogenic vasodilatation of intracranial blood vessels. At the first order synapse of the trigeminal sensory system, naratriptan can selectively suppress neurotransmission from sensory fibers from dural and vascular tissue, while sparing transmission from other trigeminal fibers, probably through inhibition of neuropeptide transmitter release. In the periaqueductal gray matter and in the nucleus raphe magnus, naratriptan selectively activates inhibitory neurons which project to the trigeminal nucleus and spinal cord and which exert inhibitory influences on trigeminovascular sensory input. Naratriptan has also a therapeutic effect on the nausea of migraine, possibly exerting its action at the level of the nucleus tractus solitarius via the same mechanisms by which it inhibits trigeminovascular nociceptive input. The incidence of naratriptan-induced adverse effects in the CNS is low and it is not an analgesic for pain other than that of vascular headache. In patients receiving selective serotonin uptake inhibitors (SSRIs) naratriptan may cause serotonin syndrome-like behavioral side effects. The mechanism of action involved in the production of behavioral and other CNS side effects of naratriptan is unknown.

2-(Anilino)imidazolines and 2-(benzyl)imidazoline derivatives as h5-HT1D serotonin receptor ligands

2-(Anilino)imidazolines were identified as novel human 5-HT(1D) receptor ligands, but offered no particular advantage over previously reported 2-(benzyl)imidazolines. Pharmacokinetic and functional data were obtained for selected 2-(benzyl)imidazoline derivatives.

Cardiovascular tolerability and safety of triptans: a review of clinical data

Triptans are not widely used in clinical practice despite their well-established efficacy, endorsement by the US Headache Consortium, and the demonstrable need to employ effective intervention to reduce migraine-associated disability. Although the relatively restricted use of triptans may be attributed to several factors, research suggests that prescribers' concerns about cardiovascular safety prominently figure in limiting their use. This article reviews clinical data--including results of clinical trials, postmarketing studies and surveillance, and pharmacodynamic studies--relevant to assessing the cardiovascular safety profile of the triptans. These data demonstrate that triptans are generally well tolerated. Chest symptoms occurring during use of triptans are usually nonserious and usually not attributed to ischemia. Incidence of triptan-associated serious cardiovascular adverse events in both clinical trials and clinical practice appears to be extremely low. When they do occur, serious cardiovascular events have most often been reported in patients at significant cardiovascular risk or in those with overt cardiovascular disease. Adverse cardiovascular events also have occurred, however, in patients without evidence of cardiovascular disease. Several lines of evidence suggest that nonischemic mechanisms are responsible for sumatriptan-associated chest symptoms, although the mechanism of chest symptoms has not been determined to date. Importantly, most of the clinical trials and clinical practice data on triptans are derived from patients without known cardiovascular disease. Therefore, the conclusions of this review cannot be extended to patients with cardiovascular disease. The cardiovascular safety profile of triptans favors their use in the absence of contraindications.

Tolerability of the triptans: clinical implications

The triptans represent a relatively new class of compounds effective in the treatment of migraine. The safety and tolerability of these drugs have been extensively investigated since the first triptan (sumatriptan) became commercially available. A report on a very large population of patients tested during clinical trials and in postmarketing studies, confirms that these drugs are safe and well tolerated when correctly used. Adverse events are frequently reported, but are usually mild and only a few patients discontinue therapy because of them. These adverse events include, in particular, the so-called 'triptan symptoms' (tingling, sensation of warmth, etc.). The exact mechanism of chest symptoms reported by 20% of patients with migraine treated with triptans remains unclear, but are exceptionally related to a cardiac mechanism. CNS adverse events (i.e. somnolence) are also reported, but it is a matter of debate whether they are related to the pharmacological properties (i.e. lipophilicity) of the drug or are symptoms of the disease itself. The potential risk for drug overuse must be taken into account when the triptans are given to patients with a high frequency of migraine attacks. Clinical interaction of triptans with other drugs metabolised in the liver may theoretically influence the incidence of adverse events, but there is little evidence to support this assumption. There is no evidence of a teratogenic risk of triptans in pregnant women taking these drugs.

Functional Imaging for the Monitoring of Clinical Outcomes of Pharmacotherapy

Functional and anatomic imaging have been used almost exclusively for diagnostic purposes. Because pharmacotherapy is expected to alter organ function, functional imaging is ideally suited to assess drug effects. The application of functional imaging techniques for this purpose has recently emerged. This paper reviews application of radiopharmaceuticals and nuclear imaging techniques to the assessment of pharmacologic effects in neurology, psychiatry, cardiology, and oncology.