GALANTAMINE HYDROBROMIDE- galantamine hydrobromide solution
Roxane Laboratories, Inc
Galantamine hydrobromide oral solution is indicated for the treatment of mild to moderate dementia of the Alzheimer’s type.
The recommended starting dosage of Galantamine hydrobromide oral solutionis 4 mg twice a day (8 mg/day). The dosage should be increased to the initial maintenance dosage 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).
Dosage increases should be based upon assessment of clinical benefit and tolerability of the previous dose.
Galantamine hydrobromide oral solutionshould 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 more than three days, the patient should be restarted at the lowest dosage and the dosage escalated to the current dose.
The abrupt withdrawal of galantamine in those patients who had been receiving dosages in the effective range was not associated with an increased frequency of adverse events in comparison with those continuing to receive the same dosages of that drug. The beneficial effects of galantamine hydrobromide oral solution are lost, however, when the drug is discontinued.
In patients with moderate hepatic impairment (Child-Pugh score of 7 to 9), the dosage should generally not exceed 16 mg/day. The use of galantamine hydrobromide oral solution in patients with severe hepatic impairment (Child-Pugh score of 10 to15) is not recommended.
In patients with creatinine clearance of 9 to 59 mL/min, the dosage should generally not exceed 16 mg/day. In patients with creatinine clearance less than 9 mL/min, the use of galantamine hydrobromide oral solution is not recommended [see Clinical Pharmacology (12.3)].
Galantamine hydrobromide oral solution, 4 mg/mL is a clear, colorless to pale yellow solution supplied in 100 mL bottles with a calibrated (in milligrams and milliliters) syringe. The minimum calibrated volume is 0.5 mL, while the maximum calibrated volume is 4 mL.
Galantamine hydrobromide oral solution is contraindicated in patients with known hypersensitivity to galantamine hydrobromide or to any excipients used in the formulation.
Serious skin reactions (Stevens-Johnson syndrome and acute generalized exanthematous pustulosis) have been reported in patients receiving galantamine. Inform patients and caregivers that the use of galantamine should be discontinued at the first appearance of a skin rash, unless the rash is clearly not drug-related. If signs or symptoms suggest a serious skin reaction, use of this drug should not be resumed and alternative therapy should be considered.
Galantamine, as a cholinesterase inhibitor, is likely to exaggerate the neuromuscular blocking effects of succinylcholine-type and similar neuromuscular blocking agents during anesthesia.
Because of their pharmacological action, cholinesterase inhibitors have vagotonic effects on the sinoatrial and atrioventricular nodes, leading to bradycardia and AV block. 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.
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 twice daily 0.4% [3/692]; 8 mg twice daily 1.3% [7/552]; 12 mg twice daily 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 galantamine have shown no increase, relative to placebo, in the incidence of either peptic ulcer disease or gastrointestinal bleeding.
Galantamine, as a predictable consequence of its pharmacological properties, has been shown to produce nausea, vomiting, diarrhea, anorexia, and weight loss. During therapy, the patient’s weight should be monitored.
Although this was not observed in clinical trials with galantamine, cholinomimetics may cause bladder outflow obstruction.
Cholinesterase inhibitors are believed to have some potential to cause generalized convulsions [see Adverse Reactions (6.2)]. Seizure activity may also be a manifestation of Alzheimer’s disease. Patients with Alzheimer’s disease should be monitored closely for seizures while taking galantamine.
Because of its cholinomimetic action, galantamine should be prescribed with care to patients with a history of severe asthma or obstructive pulmonary disease. Respiratory function should be monitored closely for the occurrence of respiratory adverse effects.
In two randomized placebo controlled trials of 2 years duration in subjects with mild cognitive impairment (MCI), a total of 13 subjects on galantamine (n=1026) and 1 patient on placebo (n=1022) died. The deaths were due to various causes which could be expected in an elderly population; about half of the galantamine deaths appeared to result from various vascular causes (myocardial infarction, stroke, and sudden death).
Although the difference in mortality between galantamine- and placebo-treated groups in these two studies was significant, the results are highly discrepant with other studies of galantamine. Specifically, in these two MCI studies, the mortality rate in the placebo-treated patients in trials of galantamine in Alzheimer’s disease or other dementias (0.7 per 1000 person years compared to 22 to 61 per 1000 person years, respectively). Although the mortality rate in the galantamine-treated MCI patients was also lower than that observed in galantamine-treated patients in Alzheimer’s disease and other dementia trials (10.2 per 1000 person years compared to 23 to 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 galantamine group. Furthermore, in the MCI studies, no patients 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.
The following are discussed in more detail in other sections of the labeling:
- Serious skin reactions [see Warnings and Precautions (5.1)]
- Deaths in subjects with mild cognitive impairment (MCI) [see Warnings and Precautions (5.8)]
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