Rilutek (Tablet, Film Coated)
The recommended dose for RILUTEK is 50 mg every 12 hours. No increased benefit can be expected from higher daily doses, but adverse events are increased. RILUTEK tablets should be taken at least an hour before, or two hours after, a meal to avoid a food-related decrease in bioavailability.<br/>Special Populations:<br/>Patients with Impaired Hepatic Function: see WARNINGS, PRECAUTIONS, CLINICAL PHARMACOLOGY.
RILUTEK' (riluzole) is a member of the benzothiazole class. Chemically, riluzole is 2-amino-6-(trifluoromethoxy)benzothiazole. Its molecular formula is CHFNOS and its molecular weight is 234.2. Its structural formula is as follows: Riluzole is a white to slightly yellow powder that is very soluble in dimethylformamide, dimethylsulfoxide and methanol, freely soluble in dichloromethane, sparingly soluble in 0.1 N HCl and very slightly soluble in water and in 0.1 N NaOH. RILUTEK is available as a capsule-shaped, white, film-coated tablet for oral administration containing 50 mg of riluzole. Each tablet is engraved with "RPR 202" on one side.<br/>Inactive Ingredients: Core: anhydrous dibasic calcium phosphate, USP; microcrystalline cellulose, NF; anhydrous colloidal silica, NF; magnesium stearate, NF; croscarmellose sodium, NF. Film coating: hypromellose, USP; polyethylene glycol 6000; titanium dioxide, USP.
Mechanism of Action: 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. The mode of action of RILUTEK 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. Riluzole has also been shown, in a single study, to delay median time to death in a transgenic mouse model of ALS. These mice express human superoxide dismutase bearing one of the mutations found in one of the familial forms of human ALS. It is also neuroprotective in various in vivo experimental models of neuronal injury involving excitotoxic mechanisms. In in vitro tests, riluzole protected cultured rat motor neurons from the excitotoxic effects of glutamic acid and prevented the death of cortical neurons induced by anoxia. Due to its blockade of glutamatergic neurotransmission, riluzole also exhibits myorelaxant and sedative properties in animal models at doses of 30 mg/kg (about 20 times the recommended human daily dose) and anticonvulsant properties at a dose of 2.5 mg/kg (about 2 times the recommended human daily dose).<br/>Pharmacokinetics: Riluzole is well-absorbed (approximately 90%), with average absolute oral bioavailability of about 60% (CV=30%). Pharmacokinetics are linear over a dose range of 25 to 100 mg given every 12 hours. A high fat meal decreases absorption, reducing AUC by about 20% and peak blood levels by about 45%. The mean elimination half-life of riluzole is 12 hours (CV=35%) after repeated doses. With multiple-dose administration, riluzole accumulates in plasma by about twofold and steady-state is reached in less than 5 days. Riluzole is 96% bound to plasma proteins, mainly to albumin and lipoproteins over the clinical concentration range. The 50 mg market tablet was equivalent, with respect to AUC, to the tablet used in the dose ranging clinical trials, while the Cwas approximately 30% higher. Both tablets have been used in clinical trials. However, if doses greater than those recommended are given, it is likely that higher plasma levels will be achieved, the safety of which has not been established .<br/>Metabolism and Elimination: Riluzole is extensively metabolized to six major and a number of minor metabolites, not all of which have been identified. Some metabolites appear pharmacologically active in in vitro assays. The metabolism of riluzole is mostly hepatic and consists of cytochrome P450-dependent hydroxylation and glucuronidation. There is marked interindividual variability in the clearance of riluzole, probably attributable to variability of CYP 1A2 activity, the principal isozyme involved in N-hydroxylation. In vitro studies using liver microsomes show that hydroxylation of the primary amine group producing N-hydroxyriluzole is the main metabolic pathway in human, monkey, dog and rabbit. In humans, cytochrome P450 1A2 is the principal isozyme involved in N-hydroxylation. In vitro studies predict that CYP 2D6, CYP 2C19, CYP 3A4 and CYP 2E1 are unlikely to contribute significantly to riluzole metabolism in humans. Whereas direct glucuroconjugation of riluzole (involving the glucurotransferase isoform UGT-HP4) is very slow in human liver microsomes, N-hydroxyriluzole is readily conjugated at the hydroxylamine group resulting in the formation of O- (>90%) and N-glucuronides. Following a single 150 mg dose ofC-riluzole to 6 healthy males, 90% and 5% of the radioactivity was recovered in the urine and feces respectively over a period of 7 days. Glucuronides accounted for more than 85% of the metabolites in urine. Only 2% of a riluzole dose was recovered in the urine as unchanged drug.<br/>Special Populations:<br/>Hepatic Impairment: The area-under-the-curve (AUC) of riluzole, after a single 50 mg oral dose, increases by about 1.7-fold in patients with mild chronic liver insufficiency (n=6; Child-Pugh's score A) and by about 3-fold in patients with moderate chronic liver insufficiency (n=6; Child-Pugh's score B) compared to healthy volunteers (n=12) . The pharmacokinetics of riluzole have not been studied in patients with severe hepatic impairment.<br/>Renal Impairment: There is no significant difference in pharmacokinetic parameters between patients with moderate (n=5; creatinine clearance 30���50 ml.min) and severe (n=7; creatinine clearance<30 ml.min) renal insufficiency and healthy volunteers (n=12) after a single oral dose of 50 mg riluzole. The pharmacokinetics of riluzole have not been studied in patients undergoing hemodialysis.<br/>Age: The pharmacokinetic parameters of riluzole after multiple dose administration (4.5 days of treatment at 50 mg riluzole b.i.d.) are not affected in the elderly (���70 years).<br/>Gender: No gender effect on riluzole pharmacokinetics has been found in young or elderly healthy subjects. However, in one placebo-controlled clinical trial with population pharmacokinetics, riluzole mean clearance was found to be 30% lower in female patients (corresponding to an approximate increase in AUC of 45%) as compared to male patients. No favorable or adverse effects of riluzole in relation to gender were seen in controlled trials, however.<br/>Smoking: Patients who smoke cigarettes eliminate riluzole 20% faster than non-smoking patients, based on a population pharmacokinetic analysis on data from 128 ALS patients, of whom 19 were smokers. However, there is no need for dosage adjustment in these patients.<br/>Race: Clearance of riluzole in Japanese subjects native to Japan was found to be 50% lower as compared to Caucasians after normalizing for body weight. Although it is not clear if this difference is due to genetic or environmental factors (e.g., smoking, alcohol, coffee, and dietary preferences), it is possible that Japanese subjects may possess a lower capacity (oxidative and/or conjugative) for metabolizing riluzole. There are no studies, however, of lower doses in Japanese subjects .<br/>Clinical Trials: The efficacy of RILUTEK as a treatment of ALS was established in two adequate and well-controlled trials in which the time to tracheostomy or death was longer for patients randomized to RILUTEK than for those randomized to placebo. These studies admitted patients with either familial or sporadic ALS, a disease duration of less than 5 years, and a baseline forced vital capacity greater than or equal to 60%. In one study, performed in France and Belgium, 155 ALS patients were followed for at least 13 months (maximum duration 18 months) after being randomized to either 100 mg/day (given 50 mg BID) of RILUTEK or placebo. Figure 1, which follows, displays the survival curves for time to death or tracheostomy. The vertical axis represents the proportion of individuals alive without tracheostomy at various times following treatment initiation (horizontal axis). Although these survival curves were not statistically significantly different when evaluated by the analysis specified in the study protocol (Logrank test p=0.12), the difference was found to be significant by another appropriate analysis (Wilcoxon test p=0.05). As seen, the study showed an early increase in survival in patients given riluzole. Among the patients in whom treatment failed during the study (tracheostomy or death) there was a difference between the treatment groups in median survival of approximately 90 days. There was no statistically significant difference in mortality at the end of the study. In the second study, performed in both Europe and North America, 959 ALS patients were followed for at least 1 year (North American centers) and up to 18 months (European centers) after being randomized to either 50, 100, 200 mg/day of RILUTEK or placebo. Figure 2, which follows, displays the survival curves for time to death or tracheostomy for patients randomized to either 100 mg/day of RILUTEK or placebo. Although these survival curves were not statistically significantly different when evaluated by the analysis specified in the study protocol (Logrank test p = 0.076), the difference was found to be significantby another appropriate analysis (Wilcoxon test p = 0.05). Not displayed in Figure 2 are the results of 50 mg/day of RILUTEK which could not be statistically distinguished from placebo and the results of 200 mg/day which are essentially identical to 100 mg/day. As seen, the study showed an early increase in survival in patients given riluzole. Among the patients in whom treatment failed during the study (tracheostomy or death) there was a difference between the treatment groups in median survival of approximately 60 days. There was no statistically significant difference in mortality at the end of the study. Although riluzole improved early survival in both studies, measures of muscle strength and neurological function did not show a benefit.
RILUTEK is contraindicated in patients who have a history of severe hypersensitivity reactions to riluzole or any of the tablet components.
RILUTEK 50 mg tablets are white, film-coated, capsule-shaped and engraved with "RPR 202" on one side. RILUTEK is supplied in bottles of 60 tablets, NDC 0075-7700-60. STORE AT CONTROLLED ROOM TEMPERATURE 20�����25��C (68�����77��F) AND PROTECT FROM BRIGHT LIGHT. KEEP OUT OF THE REACH OF CHILDREN.
dailymed-ingredient:anhydrous_colloidal_silica, dailymed-ingredient:anhydrous_dibasic_calcium_phosphate, dailymed-ingredient:croscarmellose_sodium, dailymed-ingredient:hypromellose, dailymed-ingredient:magnesium_stearate, dailymed-ingredient:microcrystalline_cellulose, dailymed-ingredient:polyethylene_glycol_6000, dailymed-ingredient:titanium_dioxide
No specific antidote or information on treatment of overdosage with RILUTEK is available. In the event of overdose, RILUTEK therapy should be discontinued immediately. Experience with riluzole overdose in humans is limited. Neurological and psychiatric symptoms, acute toxic encephalopathy with stupor, coma, and methemoglobinemia have been observed in isolated cases. Treatment should be supportive and directed toward alleviating symptoms. Severe methemoglobinemia may be rapidly reversible after treatment with methylene blue. The estimated oral median lethal dose is 94 mg/kg and 39 mg/kg for male mice and rats, respectively.
Rilutek (Tablet, Film Coated)
The most commonly observed AEs associated with the use of RILUTEK more frequently than placebo treated patients were: asthenia, nausea, dizziness, decreased lung function, diarrhea, abdominal pain, pneumonia, vomiting, vertigo, circumoral paresthesia, anorexia, and somnolence. Asthenia, nausea, dizziness, diarrhea, anorexia, vertigo, somnolence, and circumoral paresthesia were dose related. Approximately 14% (n = 141) of the 982 individuals with ALS who received RILUTEK in pre-marketing clinical trials discontinued treatment because of an adverse experience. Of those patients who discontinued due to adverse events, the most commonly reported were: nausea, abdominal pain, constipation, and ALT elevations. In a dose response study in ALS patients, the rates of discontinuation of RILUTEK for asthenia, nausea, abdominal pain, and ALT elevation were dose related.<br/>Incidence in Controlled ALS Clinical Studies: Table 1 lists treatment-emergent signs and symptoms that occurred in at least 2% of patients with ALS treated with RILUTEK (n=794) participating in placebo-controlled trials and were numerically greater in the patients treated with RILUTEK 100 mg/day than with placebo or for which a dose response relationship is suggested. The prescriber should be aware that these figures cannot be used to predict the frequency of adverse experiences in the course of usual medical practice where patient characteristics and other factors may differ from those prevailing during clinical studies. Inspection of these frequencies, however, does provide the prescriber with one basis to estimate the relative contribution of drug and non-drug factors to the AE incidences in the population studied.<br/>Other Adverse Events Observed: Other events which occurred in more than 2% of patients treated with RILUTEK 100 mg/day but equally or more frequently in the placebo group included: accidental injury, apnea, bronchitis, constipation, death, dysphagia, dyspnea, flu syndrome, heart arrest, increased sputum, pneumonia, and respiratory disorder. The overall adverse event profile for RILUTEK was similar between females and males, and was independent of age. Because the largest non-white racial subgroup was only 2% of patients exposed to RILUTEK (18/794) in placebo-controlled trials, there are insufficient data to support a statement regarding the distribution of adverse experience reports by race. In ALS studies, dizziness did occur more commonly in females (11%) than in males (4%). There was not a difference between females and males in the rates of discontinuation of RILUTEK for individualadverse experiences.<br/>Other Adverse Events Observed During All Clinical Trials: RILUTEK has been administered to 1713 individuals during all clinical trials, some of which were placebo-controlled. During these trials, all adverse events were recorded by the clinical investigators using terminology of their own choosing. To provide a meaningful estimate of the proportion of individuals having adverse events, similar types of events were grouped into a smaller number of standardized categories using modified COSTART dictionary terminology. The frequencies presented represent the proportion of the 1713 individuals exposed to RILUTEK who experienced an event of the type cited on at least one occasion while receiving RILUTEK. All reported events are included except those already listed in the previous table, those too general to be informative, and those not reasonably associated with the use of the drug. Events are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse events are defined as those occurring in at least 1/100 patients; infrequent adverse events are those occurring in 1/100 to 1/1000 patients; rare adverse events are those occurring in fewer than 1/1000 patients. Body as a Whole: Frequent: Hostility. Infrequent: Abscess, sepsis, photosensitivity reaction, cellulitis, face edema, hernia, peritonitis, attempted suicide, injection site reaction, chills, flu syndrome, intentional injury, enlarged abdomen, neoplasm. Rare: Acrodynia, hypothermia, moniliasis, rheumatoid arthritis. Digestive System: Infrequent: Increased appetite, intestinal obstruction, fecal impaction, gastrointestinal hemorrhage, gastrointestinal ulceration, gastritis, fecal incontinence, jaundice, hepatitis, glossitis, gum hemorrhage, pancreatitis, tenesmus, esophageal stenosis. Rare: Cheilitis, cholecystitis, hematemesis, melena, biliary pain, proctitis, pseudomembranous enterocolitis, enlarged salivary gland, tongue discoloration, tooth caries. Nervous System: Frequent: Agitation, tremor. Infrequent: Hallucinations, personality disorder, abnormal thinking, coma, paranoid reaction, manic reaction, ataxia, extrapyramidal syndrome, hypokinesia, urinary retention, emotional lability, delusions, apathy, hypesthesia, incoordination, confusion, convulsion, leg cramps, amnesia, dysarthria, increased libido, stupor, subdural hematoma, abnormal gait, delirium, depersonalization, facial paralysis, hemiplegia, decreased libido, myoclonus. Rare: Abnormal dreams, acute brain syndrome, CNS depression, dementia, cerebral embolism, euphoria, hypotonia, ileus, peripheral neuritis, psychosis, psychotic depression, schizophrenic reaction, trismus, wristdrop. Skin and Appendages: Infrequent: Skin ulceration, urticaria, psoriasis, seborrhea, skin disorder, fungal dermatitis. Rare: Anaphylactoid reaction, angioedema, contact dermatitis, erythema multiforme, furunculosis, skin moniliasis, skin granuloma, skin nodule. Respiratory System: Infrequent: Hiccup, pleural disorder, asthma, epistaxis, hemoptysis, yawn, hyperventilation, lung edema, hypoventilation, lung carcinoma, hypoxia, laryngitis, pleural effusion, pneumothorax, respiratory moniliasis, stridor. Cardiovascular System: Infrequent: Syncope, hypotension, heart failure, migraine, peripheral vascular disease, angina pectoris, myocardial infarction, ventricular extrasystoles, cerebral hemorrhage, atrial fibrillation, bundle branch block, congestive heart failure, pericarditis, lower extremity embolus, myocardial ischemia, shock. Rare: Bradycardia, cerebral ischemia, hemorrhage, mesenteric artery occlusion, subarachnoid hemorrhage, supraventricular tachycardia, thrombosis, ventricular fibrillation, ventricular tachycardia. Metabolic and Nutritional Disorders: Infrequent: Gout, respiratory acidosis, edema, thirst, hypokalemia, hyponatremia, weight gain. Rare: Generalized edema, hypercalcemia, hypercholesteremia. Endocrine System: Infrequent: Diabetes mellitus, thyroid neoplasia. Rare: Diabetes insipidus, parathyroid disorder. Hemic and Lymphatic System: Infrequent: Anemia, leukocytosis, leukopenia, ecchymosis. Rare: Neutropenia, aplastic anemia, cyanosis, hypochromic anemia, iron deficiency anemia, lymphadenopathy, petechiae, purpura. Musculoskeletal System: Infrequent: Arthrosis, myasthenia, bone neoplasm. Rare: Bone necrosis, osteoporosis, tetany. Special Senses: Infrequent: Amblyopia, ophthalmitis. Rare: Blepharitis, cataract, deafness, diplopia, ear pain, glaucoma, hyperacusis, photophobia, taste loss, vestibular disorder. Urogenital System: Infrequent: Urinary urgency, urine abnormality, urinary incontinence, kidney calculus, hematuria, impotence, prostate carcinoma, kidney pain, metrorrhagia, priapism. Rare: Amenorrhea, breast abscess, breast pain, nephritis, nocturia, pyelonephritis, enlarged uterine fibroids, uterine hemorrhage, vaginal moniliasis. Laboratory Tests: Infrequent: Increased gamma glutamyl transferase, abnormal liver function/tests, increased alkaline phosphatase, positive direct Coombs test, increased gamma globulins. Rare: increased lactic dehydrogenase.
RILUTEK is indicated for the treatment of patients with amyotrophic lateral sclerosis (ALS). Riluzole extends survival and/or time to tracheostomy.