Rizatriptan

Pharmaceuticals -> Listed in ZINC15

Pharmaceuticals

178-180

178 - 180 °C

Danger

H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P203, P260, P261, P264, P264+P265, P270, P271, P280, P304+P340, P305+P351+P338, P318, P319, P337+P317, P403+P233, P405, and P501 (click each P-code to see the statement)

The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory.

Gastrointestinal decontamination, (i.e., gastric lavage followed by activated charcoal) should be considered in patients suspected of an overdose with Rizatriptan. Clinical and electrocardiographic monitoring should be continued for at least 12 hours, even if clinical symptoms are not observed. (L1712)

Rapid following oral administration. Bioavailability is 45%. Food has no effect on the bioavailability of rizatriptan. However, administering rizatriptan with food will delay by 1 hour the time to reach peak plasma concentration. The rate of absorption is not affected by the presence of a migraine attack.

Three distinct pharmacological actions have been implicated in the antimigraine effect of the triptans: (1) stimulation of presynaptic 5-HT1D receptors, which serves to inhibit both dural vasodilation and inflammation; (2) direct inhibition of trigeminal nuclei cell excitability via 5-HT1B/1D receptor agonism in the brainstem and (3) vasoconstriction of meningeal, dural, cerebral or pial vessels as a result of vascular 5-HT1B receptor agonism.

Drug-Induced Liver Injury Severity and Toxicity (DILIst)

rizatriptan

DILI Negative

Oral

DOI:10.1016/j.drudis.2019.09.022

N02CC04

N - Nervous system

QN - Nervous system

Rizatriptan relieves migraine-associated symptoms. Rizatriptan is reported to reach the maximum plasma concentrations more quickly and produces a more rapid onset of pain relief than other triptans, such as [sumatriptan]; however, it has a relatively shorter elimination half-life than other triptans. Rizatriptan causes transient increases in blood pressure to some extent. _In vitro_, rizatriptan was shown to contract isolated human coronary arteries; however, since the EC₅₀ for this effect is high, rizatriptan is not expected to cause myocardial ischemia at therapeutic plasma concentrations in patients with normal coronary circulation. Rizatriptan has a weak affinity for other 5-HT1 receptor subtypes (5-HT_1A, 5-HT_1E, 5-HT_1F) and the 5-HT₇ receptor but has no significant activity at 5-HT₂, 5-HT₃, alpha- and beta-adrenergic, dopaminergic, histaminergic, muscarinic or benzodiazepine receptors.

There are several physiological and molecular processes implicated in the pathophysiology of migraine. Vasodilation of intracranial extracerebral blood vessels, particularly those supplying the dura mater, has been associated with migraine pain. Activation of the trigeminovascular system leads to the release of vasoactive neuropeptides (such as substance P, calcitonin gene-related peptide (CGRP), and neurokinin A) from the trigeminal nerve innervating the intracranial vessels and dura mater. Vasoactive neuropeptides cause perivascular inflammation and vasodilation in the periphery. Migraine-associated nausea and vomiting are thought to arise from the activation of central and nociceptive sensory neurons that project to autonomic brain-stem nuclei and higher subcortical and cortical pain processing centres. An imbalance in serotonin (5-HT) levels has also been documented: 5-HT binds to 5-HT_1B and 5-HT_1D receptors to promote trigeminal neuronal firing and vasoconstriction. Rizatriptan is a selective agonist at the 5-HT_1B and 5-HT_1D receptors on intracranial blood vessels and sensory nerves of the trigeminal system. It binds to these receptors with high affinity. The exact mechanism of action of rizatriptan has not been fully elucidated; however, several documented pharmacological actions of rizatriptan may contribute to its antimigraine effects. Rizatriptan causes vasoconstriction of intracranial extracerebral blood vessels, which is thought to occur primarily via 5-HT_1B receptors. Rizatriptan also inhibits nociceptive neurotransmission in trigeminal pain pathways. It attenuates the release of vasoactive neuropeptides by the trigeminal nerve, which is thought to occur via neurogenic and central 5-HT_1D receptors. Rizatriptan inhibited neurogenic dural vasodilation and plasma protein extravasation in animal studies.

Rizatriptan primarily undergoes oxidative deamination mediated by monoamine oxidase-A (MAO-A) to form triazolomethyl-indole-3-acetic acid, which is not pharmacologically active. N-monodesmethyl-rizatriptan is a minor metabolite with a pharmacological activity comparable to the parent compound's. Plasma concentrations of N-monodesmethyl-rizatriptan are approximately 14% of those of the parent compound, which is eliminated at a similar rate. Other pharmacologically inactive minor metabolites include the N-oxide, the 6-hydroxy compound, and the sulfate conjugate of the 6-hydroxy metabolite.

Rizatriptan is metabolized by monoamine oxidase A isoenzyme (MAO-A) to an inactive indole acetic acid metabolite. In addition, several other inactive metabolites are formed. An active metabolite, N-monodesmethyl-rizatriptan, with pharmacological activity similar to that of the parent compound has been identified in small concentrations (14%) in the plasma. Route of Elimination: Approximately 14% of an oral dose is excreted in urine as unchanged rizatriptan while 51% is excreted as indole acetic acid metabolite, indicating substantial first pass metabolism. Half Life: 2-3 hours

51086HBW8G

RIZATRIPTAN

Mechanisms of Action [MoA] - Serotonin 1b Receptor Agonists

Mechanisms of Action [MoA] - Serotonin 1d Receptor Agonists

Established Pharmacologic Class [EPC] - Serotonin-1b and Serotonin-1d Receptor Agonist

Rizatriptan is a Serotonin-1b and Serotonin-1d Receptor Agonist. The mechanism of action of rizatriptan is as a Serotonin 1b Receptor Agonist and Serotonin 1d Receptor Agonist.

Rizatriptan is readily absorbed (approximately 90%) following oral administration; however, the mean oral absolute bioavailability of the rizatriptan tablet is about 45%, owing to extensive first-pass metabolism. The Tmax is approximately one to 1.5 hours. The presence of a migraine headache did not appear to affect the absorption or pharmacokinetics of rizatriptan. Food has no significant effect on the bioavailability of rizatriptan but delays the time to reach peak concentration by an hour. In clinical trials, rizatriptan was administered without regard to food. The bioavailability and Cmax of rizatriptan were similar following the administration of rizatriptan tablets and rizatriptan orally disintegrating tablets. Still, the absorption rate is somewhat slower with orally disintegrating tablets, with Tmax delayed by up to 0.7 hours. The AUC of rizatriptan is approximately 30% higher in females than males. No accumulation occurred on multiple dosing.

Following oral administration of a single 10 mg of ¹⁴C-rizatriptan, the total radioactivity of the administered dose recovered over 120 hours in urine and feces was 82% and 12%, respectively. Following oral administration of 14C-rizatriptan, rizatriptan accounted for about 17% of circulating plasma radioactivity. Approximately 14% of an oral dose is excreted in urine as unchanged rizatriptan, while 51% is excreted as indole acetic acid metabolite, indicating substantial first-pass metabolism.

The mean volume of distribution is approximately 140 L in male subjects and 110 L in female subjects.

An early study involving healthy subject reported plasma clearance of 1042 mL/min in males and 821 mL/min in females; however, this difference in clearance rates is not thought to be clinically relevant.