Razadyne Information
Razadyne (Galantamine hydrobromide) Description
Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) is galantamine hydrobromide, a reversible, competitive acetylcholinesterase inhibitor. Galantamine hydrobromide is known chemically as (4a,6,8a)-4a,5,9,10,11,12-hexahydro-3-methoxy-11-methyl-6-benzofuro[3a,3,2-][2]benzazepin-6-ol hydrobromide. It has an empirical formula of CHNO •HBr and a molecular weight of 368.27. Galantamine hydrobromide is a white to almost white powder and is sparingly soluble in water. The structural formula for galantamine hydrobromide is:
Razadyne (Galantamine hydrobromide) ER is available in opaque hard gelatin extended-release capsules of 8 mg (white), 16 mg (pink), and 24 mg (caramel) containing galantamine hydrobromide, equivalent to respectively 8, 16 and 24 mg galantamine base. Inactive ingredients include gelatin, diethyl phthalate, ethylcellulose, hypromellose, polyethylene glycol, titanium dioxide and sugar spheres (sucrose and starch). The 16 mg capsule also contains red ferric oxide. The 24 mg capsule also contains red ferric oxide and yellow ferric oxide.
Razadyne (Galantamine hydrobromide) for oral use is available in circular biconvex film-coated immediate-release tablets of 4 mg (off-white), 8 mg (pink), and 12 mg (orange-brown). Each 4, 8, and 12 mg (base equivalent) tablet contains 5.126, 10.253, and 15.379 mg of galantamine hydrobromide, respectively. Inactive ingredients include colloidal silicon dioxide, crospovidone, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, propylene glycol, talc, and titanium dioxide. The 4 mg tablets contain yellow ferric oxide. The 8 mg tablets contain red ferric oxide. The 12 mg tablets contain red ferric oxide and FD&C yellow #6 aluminum lake.
Razadyne (Galantamine hydrobromide) is also available as a 4 mg/mL oral solution. The inactive ingredients for this solution are methyl parahydroxybenzoate, propyl parahydroxybenzoate, sodium saccharin, sodium hydroxide and purified water.
Razadyne (Galantamine hydrobromide) Clinical Pharmacology
Although the etiology of cognitive impairment in Alzheimer's disease (AD) is not fully understood, it has been reported that acetylcholine-producing neurons degenerate in the brains of patients with Alzheimer's disease. The degree of this cholinergic loss has been correlated with degree of cognitive impairment and density of amyloid plaques (a neuropathological hallmark of Alzheimer's disease).
Galantamine, a tertiary alkaloid, is a competitive and reversible inhibitor of acetylcholinesterase. While the precise mechanism of galantamine's action is unknown, it is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by cholinesterase. If this mechanism is correct, galantamine's effect may lessen as the disease process advances and fewer cholinergic neurons remain functionally intact. There is no evidence that galantamine alters the course of the underlying dementing process.
Galantamine is well absorbed with absolute oral bioavailability of about 90%. It has a terminal elimination half-life of about 7 hours and pharmacokinetics are linear over the range of 8-32 mg/day.
The maximum inhibition of acetylcholinesterase activity of about 40% was achieved about one hour after a single oral dose of 8 mg galantamine in healthy male subjects.
(see also )
Multiple metabolic pathways and renal excretion are involved in the elimination of galantamine so no single pathway appears predominant. Based on studies, CYP2D6 and CYP3A4 were the major enzymes involved in the metabolism of galantamine. CYP2D6 was involved in the formation of O-desmethyl-galantamine, whereas CYP3A4 mediated the formation of galantamine-N-oxide. Galantamine is also glucuronidated and excreted unchanged in urine.
Razadyne (Galantamine hydrobromide) Clinical Trials
The effectiveness of Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) as a treatment for Alzheimer's disease is demonstrated by the results of 5 randomized, double-blind, placebo-controlled clinical investigations in patients with probable Alzheimer's disease, 4 with the immediate-release tablet and 1 with the extended-release capsule [diagnosed by NINCDS-ADRDA criteria, with Mini-Mental State Examination scores that were≥ 10 and ≤ 24]. Doses studied with the tablet formulation were 8-32 mg/day given as twice daily doses. In 3 of the 4 studies with the tablet, patients were started on a low dose of 8 mg, then titrated weekly by 8 mg/day to 24 or 32 mg as assigned. In the fourth study (USA 4-week Dose-Escalation Fixed-Dose Study) dose escalation of 8 mg/day occurred over 4 week intervals. The mean age of patients participating in these 4 Razadyne (Galantamine hydrobromide) trials was 75 years with a range of 41 to 100. Approximately 62% of patients were women and 38% were men. The racial distribution was White 94%, Black 3% and other races 3%. Two other studies examined a three times daily dosing regimen; these also showed or suggested benefit but did not suggest an advantage over twice daily dosing.
In each study, the primary effectiveness of Razadyne (Galantamine hydrobromide) was evaluated using a dual outcome assessment strategy as measured by the Alzheimer's Disease Assessment Scale (ADAS-cog) and the Clinician's Interview Based Impression of Change that required the use of caregiver information (CIBIC-plus).
The ability of Razadyne (Galantamine hydrobromide) to improve cognitive performance was assessed with the cognitive sub-scale of the Alzheimer's Disease Assessment Scale (ADAS-cog), a multi-item instrument that has been extensively validated in longitudinal cohorts of Alzheimer's disease patients. The ADAS-cog examines selected aspects of cognitive performance including elements of memory, orientation, attention, reasoning, language and praxis. The ADAS-cog scoring range is from 0 to 70, with higher scores indicating greater cognitive impairment. Elderly normal adults may score as low as 0 or 1, but it is not unusual for non-demented adults to score slightly higher.
The patients recruited as participants in each study using the tablet formulation had mean scores on ADAS-cog of approximately 27 units, with a range from 5 to 69. Experience gained in longitudinal studies of ambulatory patients with mild to moderate Alzheimer's disease suggests that they gain 6 to 12 units a year on the ADAS-cog. Lesser degrees of change, however, are seen in patients with very mild or very advanced disease because the ADAS-cog is not uniformly sensitive to change over the course of the disease. The annualized rate of decline in the placebo patients participating in Razadyne (Galantamine hydrobromide) trials was approximately 4.5 units per year.
The ability of Razadyne (Galantamine hydrobromide) to produce an overall clinical effect was assessed using a Clinician's Interview Based Impression of Change that required the use of caregiver information, the CIBIC-plus. The CIBIC-plus is not a single instrument and is not a standardized instrument like the ADAS-cog. Clinical trials for investigational drugs have used a variety of CIBIC formats, each different in terms of depth and structure. As such, results from a CIBIC-plus reflect clinical experience from the trial or trials in which it was used and cannot be compared directly with the results of CIBIC-plus evaluations from other clinical trials. The CIBIC-plus used in the trials was a semi-structured instrument based on a comprehensive evaluation at baseline and subsequent time-points of 4 major areas of patient function: general, cognitive, behavioral and activities of daily living. It represents the assessment of a skilled clinician based on his/her observation at an interview with the patient, in combination with information supplied by a caregiver familiar with the behavior of the patient over the interval rated. The CIBIC-plus is scored as a seven point categorical rating, ranging from a score of 1, indicating “markedly improved,” to a score of 4, indicating “no change” to a score of 7, indicating “marked worsening.” The CIBIC-plus has not been systematically compared directly to assessments not using information from caregivers (CIBIC) or other global methods.
Razadyne (Galantamine hydrobromide) Indications And Usage
Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) is indicated for the treatment of mild to moderate dementia of the Alzheimer's type.
Razadyne (Galantamine hydrobromide) Contraindications
Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) is contraindicated in patients with known hypersensitivity to galantamine hydrobromide or to any excipients used in the formulation.
Razadyne (Galantamine hydrobromide) Warnings
Because of their pharmacological action, cholinesterase inhibitors have vagotonic effects on the sinoatrial and atrioventricular nodes, leading to bradycardia and AV block. These actions may be particularly important to patients with supraventricular cardiac conduction disorders or to patients taking other drugs concomitantly that significantly slow heart rate. Postmarketing surveillance of marketed anticholinesterase inhibitors has shown, however, that bradycardia and all types of heart block have been reported in patients both with and without known underlying cardiac conduction abnormalities. Therefore all patients should be considered at risk for adverse effects on cardiac conduction.
In randomized controlled trials, bradycardia was reported more frequently in galantamine-treated patients than in placebo-treated patients, but was rarely severe and rarely led to treatment discontinuation. The overall frequency of this event was 2-3% for galantamine doses up to 24 mg/day compared with <1% for placebo. No increased incidence of heart block was observed at the recommended doses.
Patients treated with galantamine up to 24 mg/day using the recommended dosing schedule showed a dose-related increase in risk of syncope (placebo 0.7% [2/286]; 4 mg BID 0.4% [3/692]; 8 mg BID 1.3% [7/552]; 12 mg BID 2.2% [6/273]).
Through their primary action, cholinomimetics may be expected to increase gastric acid secretion due to increased cholinergic activity. Therefore, patients should be monitored closely for symptoms of active or occult gastrointestinal bleeding, especially those with an increased risk for developing ulcers, e.g., those with a history of ulcer disease or patients using concurrent nonsteroidal anti-inflammatory drugs (NSAIDS). Clinical studies of Razadyne (Galantamine hydrobromide) have shown no increase, relative to placebo, in the incidence of either peptic ulcer disease or gastrointestinal bleeding.
Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) , as a predictable consequence of its pharmacological properties, has been shown to produce nausea, vomiting, diarrhea, anorexia, and weight loss (see ).
Razadyne (Galantamine hydrobromide) Precautions
Caregivers should be instructed about the recommended dosage and administration of Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) (galantamine hydrobromide). Razadyne (Galantamine hydrobromide) ER Extended-Release Capsules should be administered once daily in the morning, preferably with food (although not required). Razadyne (Galantamine hydrobromide) Tablets and Oral Solution should be administered twice per day, preferably with the morning and evening meals. Dose escalation (dose increases) should follow a minimum of four weeks at prior dose.
Patients and caregivers should be advised that the most frequent adverse events associated with use of the drug can be minimized by following the recommended dosage and administration.
Patients and caregivers should be advised to ensure adequate fluid intake during treatment. If therapy has been interrupted for several days or longer, the patient should be restarted at the lowest dose and the dose escalated to the current dose.
Caregivers should be instructed in the correct procedure for administering Razadyne (Galantamine hydrobromide) Oral Solution. In addition, they should be informed of the existence of an Instruction Sheet (included with the product) describing how the solution is to be administered. They should be urged to read this sheet prior to administering Razadyne (Galantamine hydrobromide) Oral Solution. Caregivers should direct questions about the administration of the solution to either their physician or pharmacist.
In two randomized placebo controlled trials of 2 years duration in subjects with mild cognitive impairment (MCI), a total of 13 subjects on Razadyne (Galantamine hydrobromide) (n=1026) and 1 subject on placebo (n=1022) died. The deaths were due to various causes which could be expected in an elderly population; about half of the Razadyne (Galantamine hydrobromide) deaths appeared to result from various vascular causes (myocardial infarction, stroke, and sudden death).
Although the difference in mortality between Razadyne (Galantamine hydrobromide) and placebo-treated groups in these two studies was significant, the results are highly discrepant with other studies of Razadyne (Galantamine hydrobromide) . Specifically, in these two MCI studies, the mortality rate in the placebo-treated subjects was markedly lower than the rate in placebo-treated patients in trials of Razadyne (Galantamine hydrobromide) in Alzheimer's disease or other dementias (0.7 per 1000 person years compared to 22-61 per 1000 person years, respectively). Although the mortality rate in the Razadyne (Galantamine hydrobromide) -treated MCI subjects was also lower than that observed in Razadyne (Galantamine hydrobromide) -treated patients in Alzheimer's disease and other dementia trials (10.2 per 1000 person years compared to 23-31 per 1000 person years, respectively), the relative difference was much less. When the Alzheimer's disease and other dementia studies were pooled (n=6000), the mortality rate in the placebo group numerically exceeded that in the Razadyne (Galantamine hydrobromide) group. Furthermore, in the MCI studies, no subjects in the placebo group died after 6 months, a highly unexpected finding in this population.
Individuals with mild cognitive impairment demonstrate isolated memory impairment greater than expected for their age and education, but do not meet current diagnostic criteria for Alzheimer's disease.
(see also
In a 24-month oral carcinogenicity study in rats, a slight increase in endometrial adenocarcinomas was observed at 10 mg/kg/day (4 times the Maximum Recommended Human Dose [MRHD] on a mg/m basis or 6 times on an exposure [AUC] basis) and 30 mg/kg/day (12 times MRHD on a mg/m basis or 19 times on an AUC basis). No increase in neoplastic changes was observed in females at 2.5 mg/kg/day (equivalent to the MRHD on a mg/m basis or 2 times on an AUC basis) or in males up to the highest dose tested of 30 mg/kg/day (12 times the MRHD on a mg/m and AUC basis).
Galantamine was not carcinogenic in a 6-month oral carcinogenicity study in transgenic (P 53-deficient) mice up to 20 mg/kg/day, or in a 24-month oral carcinogenicity study in male and female mice up to 10 mg/kg/day (2 times the MRHD on a mg/m basis and equivalent on an AUC basis).
Galantamine produced no evidence of genotoxic potential when evaluated in the Ames or reverse mutation assay, mouse lymphoma assay, micronucleus test in mice, or chromosome aberration assay in Chinese hamster ovary cells.
No impairment of fertility was seen in rats given up to 16 mg/kg/day (7 times the MRHD on a mg/m basis) for 14 days prior to mating in females and for 60 days prior to mating in males.
Pregnancy Category B: In a study in which rats were dosed from day 14 (females) or day 60 (males) prior to mating through the period of organogenesis, a slightly increased incidence of skeletal variations was observed at doses of 8 mg/kg/day (3 times the Maximum Recommended Human Dose [MRHD] on a mg/m basis) and 16 mg/kg/day. In a study in which pregnant rats were dosed from the beginning of organogenesis through day 21 post-partum, pup weights were decreased at 8 and 16 mg/kg/day, but no adverse effects on other postnatal developmental parameters were seen. The doses causing the above effects in rats produced slight maternal toxicity. No major malformations were caused in rats given up to 16 mg/kg/day. No drug related teratogenic effects were observed in rabbits given up to 40 mg/kg/day (32 times the MRHD on a mg/m basis) during the period of organogenesis.
There are no adequate and well-controlled studies of Razadyne (Galantamine hydrobromide) in pregnant women. Razadyne (Galantamine hydrobromide) should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Razadyne (Galantamine hydrobromide) Adverse Reactions
Other adverse events from post-approval controlled and uncontrolled clinical trials and post-marketing experience observed in patients treated with Razadyne (Galantamine hydrobromide) include:
Body as a Whole – General Disorders:
Psychiatric Disorders:
Gastrointestinal System Disorders:
Hepatobiliary Disorders:
Metabolic& Nutritional Disorders:
Nervous System Disorders:
Eye disorders:
These adverse events may or may not be causally related to the drug.
Razadyne (Galantamine hydrobromide) Overdosage
Because strategies for the management of overdose are continually evolving, it is advisable to contact a poison control center to determine the latest recommendations for the management of an overdose of any drug.
As in any case of overdose, general supportive measures should be utilized. Signs and symptoms of significant overdosing of galantamine are predicted to be similar to those of overdosing of other cholinomimetics. These effects generally involve the central nervous system, the parasympathetic nervous system, and the neuromuscular junction. In addition to muscle weakness or fasciculations, some or all of the following signs of cholinergic crisis may develop: severe nausea, vomiting, gastrointestinal cramping, salivation, lacrimation, urination, defecation, sweating, bradycardia, hypotension, respiratory depression, collapse and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved.
Tertiary anticholinergics such as atropine may be used as an antidote for Razadyne (Galantamine hydrobromide) overdosage. Intravenous atropine sulfate titrated to effect is recommended at an initial dose of 0.5 to 1.0 mg i.v. with subsequent doses based upon clinical response. Atypical responses in blood pressure and heart rate have been reported with other cholinomimetics when coadministered with quaternary anticholinergics. It is not known whether Razadyne (Galantamine hydrobromide) and/or its metabolites can be removed by dialysis (hemodialysis, peritoneal dialysis, or hemofiltration). Dose-related signs of toxicity in animals included hypoactivity, tremors, clonic convulsions, salivation, lacrimation, chromodacryorrhea, mucoid feces, and dyspnea.
In one postmarketing report, one patient who had been taking 4 mg of galantamine daily for a week inadvertently ingested eight 4 mg tablets (32 mg total) on a single day. Subsequently, she developed bradycardia, QT prolongation, ventricular tachycardia and torsades de pointes accompanied by a brief loss of consciousness for which she required hospital treatment. Two additional cases of accidental ingestion of 32 mg (nausea, vomiting, and dry mouth; nausea, vomiting, and substernal chest pain) and one of 40 mg (vomiting), resulted in brief hospitalizations for observation with full recovery. One patient who was prescribed 24 mg/day and had a history of hallucinations over the previous two years, mistakenly received 24 mg twice daily for 34 days and developed hallucinations requiring hospitalization. Another patient, who was prescribed 16 mg/day of oral solution, inadvertently ingested 160 mg (40 mL) and experienced sweating, vomiting, bradycardia, and near-syncope one hour later, which necessitated hospital treatment. His symptoms resolved within 24 hours.
Razadyne (Galantamine hydrobromide) Dosage And Administration
The dosage of Razadyne (Galantamine hydrobromide) ER (galantamine hydrobromide) Extended-Release Capsules was shown to be effective in a controlled clinical trial is 16-24mg/day.
The recommended starting dose of Razadyne (Galantamine hydrobromide) ER is 8 mg/day. The dose should be increased to the initial maintenance dose of 16 mg/day after a minimum of 4 weeks. A further increase to 24 mg/day should be attempted after a minimum of 4 weeks at 16 mg/day. Dose increases should be based upon assessment of clinical benefit and tolerability of the previous dose.
Razadyne (Galantamine hydrobromide) ER should be administered once daily in the morning, preferably with food.
Patients currently being treated with Razadyne (Galantamine hydrobromide) tablets can convert to Razadyne (Galantamine hydrobromide) ER by taking their last dose of Razadyne (Galantamine hydrobromide) tablets in the evening and starting Razadyne (Galantamine hydrobromide) ER once daily treatment the next morning. Converting from Razadyne (Galantamine hydrobromide) to Razadyne (Galantamine hydrobromide) ER should occur at the same total daily dose.
The dosage of Razadyne (Galantamine hydrobromide) Tablets was shown to be effective in controlled clinical trials is 16-32 mg/day given as twice daily dosing. As the dose of 32 mg/day is less well tolerated than lower doses and does not provide increased effectiveness, the recommended dose range is 16-24 mg/day given in a BID regimen. The dose of 24 mg/day did not provide a statistically significant greater clinical benefit than 16 mg/day. It is possible, however, that a daily dose of 24 mg of Razadyne (Galantamine hydrobromide) might provide additional benefit for some patients.
The recommended starting dose of Razadyne (Galantamine hydrobromide) Tablets and Oral Solution is 4 mg twice a day (8 mg/day). The dose should be increased to the initial maintenance dose of 8 mg twice a day (16 mg/day) after a minimum of 4 weeks. A further increase to 12 mg twice a day (24 mg/day) should be attempted after a minimum of 4 weeks at 8 mg twice a day (16 mg/day). Dose increases should be based upon assessment of clinical benefit and tolerability of the previous dose.
Razadyne (Galantamine hydrobromide) Tablets and Oral Solution should be administered twice a day, preferably with morning and evening meals.
Patients and caregivers should be advised to ensure adequate fluid intake during treatment. If therapy has been interrupted for several days or longer, the patient should be restarted at the lowest dose and the dose escalated to the current dose.
Caregivers should be instructed in the correct procedure for administering Razadyne (Galantamine hydrobromide) Oral Solution. In addition, they should be informed of the existence of an Instruction Sheet (included with the product) describing how the solution is to be administered. They should be urged to read this sheet prior to administering Razadyne (Galantamine hydrobromide) Oral Solution. Caregivers should direct questions about the administration of the solution to either their physician or pharmacist.
The abrupt withdrawal of Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) in those patients who had been receiving doses in the effective range was not associated with an increased frequency of adverse events in comparison with those continuing to receive the same doses of that drug. The beneficial effects of Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) are lost, however, when the drug is discontinued.
Galantamine plasma concentrations may be increased in patients with moderate to severe hepatic impairment. In patients with moderately impaired hepatic function (Child-Pugh score of 7-9), the total daily dose should generally not exceed 16 mg/day. The use of Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) in patients with severe hepatic impairment (Child-Pugh score of 10-15) is not recommended.
For patients with moderate renal impairment the dose should generally not exceed 16 mg/day. In patients with severe renal impairment (creatinine clearance < 9 mL/min), the use of Razadyne (Galantamine hydrobromide) ER/Razadyne (Galantamine hydrobromide) is not recommended.
Razadyne (Galantamine hydrobromide) How Supplied
Razadyne (Galantamine hydrobromide) Tablets are imprinted “JANSSEN” on one side, and “G” and the strength “4”, “8”, or “12” on the other.
4 mg off-white tablet: bottles of 30 NDC 21695-184-30
12 mg orange-brown tablet: bottles of 30 NDC 21695-591-30
Razadyne (Galantamine hydrobromide) Principal Display Panel
Razadyne (Galantamine hydrobromide) Principal Display Panel
