Riluzole HCl
Riluzole HCl - General Information
A glutamate antagonist (receptors, glutamate) used as an anticonvulsant (anticonvulsants) and to prolong the survival of patients with amyotrophic lateral sclerosis. [PubChem]
Pharmacology of Riluzole HCl
Riluzole HCl, a member of the benzothiazole class, is indicated for the treatment of patients with amyotrophic lateral sclerosis (ALS). Riluzole HCl extends survival and/or time to tracheostomy. It is also neuroprotective in various in vivo experimental models of neuronal injury involving excitotoxic mechanisms. The etiology and pathogenesis of amyotrophic lateral sclerosis (ALS) are not known, although a number of hypotheses have been advanced. One hypothesis is that motor neurons, made vulnerable through either genetic predisposition or environmental factors, are injured by glutamate. In some cases of familial ALS the enzyme superoxide dismutase has been found to be defective.
Riluzole HCl for patients
Patients should be advised to report any febrile illness to their physicians.
Patients and caregivers should be advised that RILUTEK should be taken on a regular basis and at the same time of the day (e.g., in the morning and evening) each day. If a dose is missed, take the next tablet as originally planned.
Patients should be warned about the potential for dizziness, vertigo, or somnolence and advised not to drive or operate machinery until they have gained sufficient experience on RILUTEK to gauge whether or not it affects their mental and/or motor performance adversely.
Whether alcohol increases the risk of serious hepatotoxicity with RILUTEK is unknown; therefore, patients being treated with RILUTEK should be discouraged from drinking excessive amounts of alcohol.
Patients should also be made aware that RILUTEK should be stored at temperatures between 20°-25°C (68°-77°F) and protected from bright light.
RILUTEK must be kept out of the reach of children.
Riluzole HCl Interactions
There have been no clinical studies designed to evaluate the interaction of riluzole with other drugs.
As with all drugs, the potential for interaction by a variety of mechanisms is a possibility.
Hepatotoxic Drugs: The clinical trials in ALS excluded patients on concomitant medications which were potentially hepatotoxic, (e.g., allopurinol, methyldopa, sulfasalazine). Accordingly, there is no information about the safety of administering RILUTEK in conjunction with such medications. If the practitioner chooses to prescribe such a combination, caution should be exercised.
Drugs Highly Bound To Plasma Proteins: Riluzole is highly bound (96%) to plasma proteins, binding mainly to serum albumin and to lipoproteins. The effect of riluzole (up to 5 mcg/mL) on warfarin (5 mcg/mL) binding did not wshow any displacement of warfarin. Conversely, riluzole binding was unaffected by the addition of warfarin, digoxin, imipramine and quinine at high therapeutic concentrations.
Effect of Other Drugs On Riluzole Metabolism: In vitro studies using human liver microsomal preparations suggest that CYP 1A2 is the principal isozyme involved in the initial oxidative metabolism of riluzole and, therefore, potential interactions may occur when riluzole is given concurrently with agents that affect CYP 1A2 activity. Potential inhibitors of CYP 1A2 (e.g., caffeine, pheriacetin, theophylline, amitriptyline, and quinolones) could decrease the rate of riluzole elimination, while inducers of CYP 1A2(e.g., cigarette smoke, charcoal broiled food, rifampicin, and omeprazole) could increase the rate of riluzole elimination.
Effect of Riluzole On the Metabolism of Other Drugs: CYP 1A2 is the principal isoenzyme involved in the initial oxidative metabolism of riluzole; potential interactions may occur when riluzole is given concurrently with other agents which are also metabolized primarily by CYP 1A2 (e.g., theophylline, caffeine and tacrine). Currently, it is not known whether riluzole has any potential for enzyme induction in humans.
Drug Laboratory Test Interactions: None known
Riluzole HCl Contraindications
RILUTEK is contraindicated in patients who have a history of severe hypersensitivity reactions to riluzole or any of the tablet components.
Additional information about Riluzole HCl
Riluzole HCl Indication: For the treatment of amyotrophic lateral sclerosis (ALS, Lou Gehrig's Disease)
Mechanism Of Action: The mode of action of riluzole is unknown. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release, 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Riluzole
Synonyms: Not Available
Drug Category: Anesthetics; Anticonvulsants; Excitatory Amino Acid Antagonists; Neuroprotective Agents
Drug Type: Small Molecule; Approved
Other Brand Names containing Riluzole: Rilutek; Riluzole HCl;
Absorption: Riluzole is well-absorbed (approximately 90%), with average absolute oral bioavailability of about 60% (CV=30%). A high fat meal decreases absorption, reducing AUC by about 20% and peak blood levels by about 45%.
Toxicity (Overdose): Not Available
Protein Binding: 96% bound to plasma proteins, mainly to albumin and lipoprotein over the clinical concentration range.
Biotransformation: Riluzole is extensively metabolized to six major and a number of minor metabolites, which have not all been identified to date. Metabolism is mostly hepatic, consisting of cytochrome P450–dependent hydroxylation and glucuronidation. CYP1A2 is the primary isozyme involved in N-hydroxylation; CYP2D6, CYP2C19, CYP3A4, and CYP2E1 are considered unlikely to contribute significantly to riluzole metabolism in humans.
Half Life: The mean elimination half-life of riluzole is 12 hours (CV=35%) after repeated doses.
Dosage Forms of Riluzole HCl: Tablet Oral
Chemical IUPAC Name: 6-(trifluoromethoxy)-1,3-benzothiazol-2-amine
Chemical Formula: C8H5F3N2OS
Riluzole on Wikipedia: https://en.wikipedia.org/wiki/Riluzole
Organisms Affected: Humans and other mammals
