2.1 Recommended Dosage and Administration

Administer galantamine hydrobromide extended-release capsules once daily in the morning, preferably with food. Ensure adequate fluid intake during treatment.

The recommended starting dosage of galantamine hydrobromide extended-release capsules is 8 mg/day. Increase to the initial maintenance dosage of 16 mg/day after a minimum of 4 weeks. A further increase to 24 mg/day may be attempted after a minimum of 4 weeks at 16 mg/day. Increase dosage based upon assessment of clinical benefit and tolerability of the previous dosage.

The dosage of galantamine hydrobromide extended-release capsules shown to be effective in a controlled clinical trial is 16 to 24 mg/day.

2.2 Dosage in Patients with Hepatic Impairment

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 extended-release capsules in patients with severe hepatic impairment (Child-Pugh score of 10 to 15) is not recommended [see Clinical Pharmacology (12.3)].

2.3 Dosage in Patients with Renal Impairment

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 extended-release capsules is not recommended [see Clinical Pharmacology (12.3)].

2.4 Treatment Interruption

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 hydrobromide extended-release capsules 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.

2.5 Switching to Galantamine Hydrobromide Extended-release Capsules from Galantamine Tablets

Patients currently being treated with galantamine tablets can convert to galantamine hydrobromide extended-release capsules by taking their last dose of galantamine tablets in the evening and starting galantamine hydrobromide extended-release capsules once daily treatment the next morning. Converting from galantamine tablets to galantamine hydrobromide extended-release capsules should occur at the same total daily dosage.

5.1 Serious Skin Reactions

Serious skin reactions (Stevens-Johnson syndrome and acute generalized exanthematous pustulosis) have been reported in patients receiving galantamine hydrobromide extended-release capsules. 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.

5.2 Anesthesia

Galantamine, as a cholinesterase inhibitor, is likely to exaggerate the neuromuscular blocking effects of succinylcholine-type and similar neuromuscular blocking agents during anesthesia.

5.3 Cardiovascular Conditions

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 [see Adverse Reactions (6.1, 6.2)]. 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]).

5.4 Gastrointestinal Conditions

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 with galantamine, the patient’s weight should be monitored.

5.5 Genitourinary Conditions

Although this was not observed in clinical trials with galantamine, cholinomimetics may cause bladder outflow obstruction.

5.6 Neurological Conditions

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 hydrobromide extended-release capsules.

An increase in cholinergic tone may worsen symptoms related to extrapyramidal disorders [see Adverse Reactions (6.2)].

5.7 Pulmonary Conditions

Because of its cholinomimetic action, galantamine hydrobromide extended-release capsules 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.

5.8 Deaths in Patients with Mild Cognitive Impairment (MCI)

In two randomized placebo-controlled trials of 2 years duration in patients with mild cognitive impairment (MCI), a total of 13 patients on galantamine (n=1,026) and 1 patient on placebo (n=1,022) 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 was markedly lower than the rate in placebo-treated patients in trials of galantamine in Alzheimer’s disease or other dementias (0.7 per 1,000 person years compared to 22 to 61 per 1,000 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 1,000 person years compared to 23 to 31 per 1,000 person years, respectively), the relative difference was much less. When the Alzheimer’s disease and other dementia studies were pooled (n=6,000), 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.

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The most common adverse reactions (≥5%) in galantamine-treated patients from double-blind clinical trials were nausea, vomiting, diarrhea, dizziness, headache, and decreased appetite.

The most common adverse reactions associated with discontinuation (≥1%) in galantamine-treated patients from double-blind clinical trials were nausea (6.2%), vomiting (3.3%), decreased appetite (1.5%), and dizziness (1.3%).

The safety of the extended-release capsule and immediate-release tablet formulations of galantamine was evaluated in 3,956 galantamine-treated patients who participated in 8 placebo-controlled clinical studies and 1,454 patients in 5 open-label clinical studies with mild to moderate dementia of the Alzheimer’s type. In clinical studies, the safety profile of once-daily treatment with extended-release galantamine was similar in frequency and nature to that seen with tablets. The information presented in this section was derived from pooled double-blind studies and from pooled open-label data.

Commonly-Observed Adverse Reactions in Double-Blind, Placebo-Controlled Clinical Trials

Table 1 lists the adverse reactions reported in ≥1% of galantamine-treated patients in 8 placebo-controlled, double-blind clinical trials.


Table 1. Adverse Reactions Reported by ≥1% of Galantamine-Treated Patients in Pooled Placebo-Controlled, Double-Blind Clinical Trials

The majority of these adverse reactions occurred during the dose-escalation period. In those patients who experienced the most frequent adverse reaction, nausea, the median duration of the nausea was 5 to 7 days.

Other Adverse Reactions Observed in Clinical Trials of Galantamine

The following adverse reactions occurred in <1% of all galantamine-treated patients (N=3,956) in the above double-blind, placebo-controlled clinical trial data sets. In addition, the following also includes all adverse reactions reported at any frequency rate in patients (N=1,454) who participated in open-label studies. Adverse reactions listed in Table 1 above were not included below:

Metabolism and Nutrition Disorders: Dehydration

Nervous System Disorders: Dysgeusia, Hypersomnia, Paresthesia

Eye Disorders: Blurred vision

Cardiac Disorders: First degree atrioventricular block, Palpitations, Sinus bradycardia, Supraventricular extrasystoles

Vascular Disorders: Flushing, Hypotension

Gastrointestinal Disorders: Retching

Skin and Subcutaneous Tissue Disorders: Hyperhidrosis

Musculoskeletal and Connective Tissue Disorders: Muscular weakness

Discontinuations Due to Adverse Reactions

In the 8 placebo-controlled studies of adults, 418 (10.6%) galantamine-treated patients (N=3,956) and 56 (2.2%) placebo patients (N=2,546) discontinued due to an adverse reaction. Those events with an incidence of ≥0.5% in the galantamine-treated patients included nausea (245, 6.2%), vomiting (129, 3.3%), decreased appetite (60, 1.5%), dizziness (50, 1.3%), diarrhea (31, 0.8%), headache (29, 0.7%), and decreased weight (26, 0.7%). The only event with an incidence of ≥0.5% in placebo patients was nausea (17, 0.7%).

In the 5 open-label studies, 103 (7.1%) patients (N=1,454) discontinued due to an adverse reaction. Those events with an incidence of ≥0.5% included nausea (43, 3.0%), vomiting (23, 1.6%), decreased appetite (13, 0.9%), headache (12, 0.8%), decreased weight (9, 0.6%), dizziness (8, 0.6%), and diarrhea (7, 0.5%).

6.2 Postmarketing Experience

The following additional adverse reactions have been identified during post-approval use of galantamine hydrobromide extended-release capsules. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

Immune System Disorders: Hypersensitivity

Psychiatric Disorders: Hallucinations

Nervous System Disorders: Seizures, extrapyramidal disorder [see Warnings and Precautions (5.6)] 

Ear and Labyrinth Disorders: Tinnitus

Cardiac Disorders: Complete atrioventricular block 

Vascular Disorders: Hypertension

Hepatobiliary Disorders: Hepatitis, increased hepatic enzyme

Skin and Subcutaneous Tissue Disorders: Stevens-Johnson syndrome, acute generalized exanthematous pustulosis, Erythema multiforme

7.1 Use with Anticholinergics

Galantamine has the potential to interfere with the activity of anticholinergic medications [see Clinical Pharmacology (12.3)].

7.2 Use with Cholinomimetics and Other Cholinesterase Inhibitors

A synergistic effect is expected when cholinesterase inhibitors are given concurrently with succinylcholine, other cholinesterase inhibitors, similar neuromuscular blocking agents or cholinergic agonists such as bethanechol [see Clinical Pharmacology (12.3)].

8.1 Pregnancy

Risk Summary

There are no adequate data on the developmental risk associated with the use of galantamine hydrobromide extended-release capsules in pregnant women. In studies conducted in animals, administration of galantamine during pregnancy resulted in developmental toxicity (increased incidence of morphological abnormalities and decreased growth in offspring) at doses similar to or greater than those used clinically (see Data).

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown.

Data

Animal Data

In rats, administration of galantamine (oral doses of 2, 8, or 16 mg/kg/day), from day 14 (females) or day 60 (males) prior to mating and continuing in females through the period of organogenesis, resulted in an increased incidence of fetal skeletal variations at the two highest doses, which were associated with maternal toxicity. The no-effect dose for embryo-fetal developmental toxicity in rats (2 mg/kg/day) is approximately equal to the maximum recommended human dose (MRHD) of 24 mg/day on a body surface area (mg/m2) basis. When galantamine (oral doses of 4, 12, 28, or 40 mg/kg/day) was administered to pregnant rabbits throughout the period of organogenesis, small increases in fetal visceral malformations and skeletal variations were observed at the highest dose which was associated with maternal toxicity. The no-effect dose for embryo-fetal developmental toxicity in rabbits (28 mg/kg/day) is approximately 20 times the MRHD on a mg/m2 basis. In a study in which pregnant rats were orally dosed with galantamine (2, 8, or 16 mg/kg/day) from the beginning of organogenesis through day 21 post-partum, pup weights were decreased at birth and during the lactation period at the two highest doses. The no-effect dose for pre- and postnatal developmental toxicity in rats (2 mg/kg/day) is approximately equal to the MRHD on a mg/m2 basis.

8.2 Lactation

Risk Summary
There are no data on the presence of galantamine in human milk, the effects on the breastfed infant, or the effects of galantamine hydrobromide extended-release capsules on milk production.  
The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for galantamine hydrobromide extended-release capsules and any potential adverse effects on the breastfed infant from galantamine hydrobromide extended-release capsules or from the underlying maternal condition.

8.4 Pediatric Use

The safety and effectiveness in pediatric patients have not been established.

8.5 Geriatric Use

Eight double-blind, placebo-controlled clinical trials and 5 open-label trials in a total of 6,519 patients have investigated galantamine hydrobromide extended-release capsules in the treatment of mild to moderate dementia of the Alzheimer’s type [see Adverse Reactions (6.1) and Clinical Studies (14)]. The mean age of patients enrolled in these clinical studies was 75 years; 78% of these patients were between 65 and 84 years of age, and 10% of patients were 85 years of age or older.

8.6 Hepatic Impairment

In patients with moderate hepatic impairment, a dosage adjustment is recommended. The use of galantamine hydrobromide extended-release capsules in patients with severe hepatic impairment is not recommended [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3)].

8.7 Renal Impairment

In patients with a creatinine clearance of 9 to 59 mL/min, a dosage adjustment is recommended. The use of galantamine hydrobromide extended-release capsules in patients with creatinine clearance less than 9 mL/min is not recommended [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].

12.1 Mechanism of Action

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.

12.2 Pharmacokinetics

The pharmacokinetics of galantamine are linear over a dose range of 8 to 32 mg/day.    

Absorption and Distribution

Galantamine is absorbed with time to peak concentration of about 1 hour. The absolute bioavailability of galantamine is about 90%. Food did not affect the AUC of galantamine, but Cmax was decreased by 25% and Tmax was delayed by 1.5 hours, when galantamine was administered with food. The mean volume of distribution of galantamine is 175 L.

The plasma protein binding of galantamine is 18% at therapeutically relevant concentrations. In whole blood, galantamine is mainly distributed to blood cells (52.7%). The blood to plasma concentration ratio of galantamine is 1.2.

Metabolism and Elimination

Galantamine is metabolized by hepatic cytochrome P450 enzymes, glucuronidated, and excreted unchanged in the urine. In vitro studies indicate that cytochrome CYP2D6 and CYP3A4 were the major cytochrome P450 isoenzymes involved in the metabolism of galantamine, and inhibitors of both pathways increase oral bioavailability of galantamine modestly. O-demethylation, mediated by CYP2D6 was greater in extensive metabolizers of CYP2D6 than in poor metabolizers. In plasma from both poor and extensive metabolizers, however, unchanged galantamine and its glucuronide accounted for most of the sample radioactivity.

In studies of oral 3H-galantamine, unchanged galantamine and its glucuronide, accounted for most plasma radioactivity in poor and extensive CYP2D6 metabolizers. Up to 8 hours post-dose, unchanged galantamine accounted for 39 to 77% of the total radioactivity in the plasma, and galantamine glucuronide for 14 to 24%. By 7 days, 93 to 99% of the radioactivity had been recovered, with about 95% in urine and about 5% in the feces. Total urinary recovery of unchanged galantamine accounted for, on average, 32% of the dose and that of galantamine glucuronide for another 12% on average.

After i.v. or oral administration, about 20% of the dose was excreted as unchanged galantamine in the urine in 24 hours, representing a renal clearance of about 65 mL/min, about 20 to 25% of the total plasma clearance of about 300 mL/min. Galantamine has a terminal half-life of about 7 hours.

Galantamine hydrobromide extended-release capsules 24 mg administered once daily under fasting conditions are bioequivalent to galantamine tablets 12 mg twice daily with respect to AUC24h and Cmin. The Cmax and Tmax of the extended-release capsules were lower and occurred later, respectively, compared with the immediate-release tablets, with Cmax about 25% lower and median Tmax occurring about 4.5 to 5 hours after dosing. Dose-proportionality is observed for galantamine hydrobromide extended-release capsules over the dose range of 8 to 24 mg daily and steady state is achieved within a week. There was no effect of age on the pharmacokinetics of galantamine hydrobromide extended-release capsules. CYP2D6 poor metabolizers had drug exposures that were approximately 50% higher than for extensive metabolizers.

There are no appreciable differences in pharmacokinetic parameters when galantamine hydrobromide extended-release capsules are given with food compared to when they are given in the fasted state.

Specific Populations

Elderly

Data from clinical trials in patients with Alzheimer’s disease indicate that galantamine concentrations are 30 to 40% higher in those patients than in healthy young subjects.

Gender and Race

A population pharmacokinetic analysis (on 539 men and 550 women) indicates that galantamine clearance is about 20% lower in women than in men (which is explained by a lower body weight in women) and that race (n=1,029 White, 24 Black, 13 Asian and 23 other) did not affect the clearance of galantamine.

Hepatic Impairment

Following a single 4 mg dose of galantamine tablets, the pharmacokinetics of galantamine in subjects with mild hepatic impairment (n=8; Child-Pugh score of 5 to 6) were similar to the pharmacokinetics of galantamine in healthy subjects. In patients with moderate hepatic impairment (n=8; Child Pugh score of 7 to 9), galantamine clearance was decreased by about 25% compared to galantamine clearance in normal volunteers. Exposure to galantamine would be expected to increase further with increasing degree of hepatic impairment [see Dosage and Administration (2.2) and Use in Specific Populations (8.6)].

Renal Impairment

Following a single 8 mg dose of galantamine tablets, AUC increased by 37% and 67% in patients with moderate and severe renal impairment, respectively, compared with normal volunteers [see Dosage and Administration (2.3) and Use in Specific Populations (8.7)].

Drug-Drug Interactions

Multiple metabolic pathways and renal excretion are involved in the elimination of galantamine so no single pathway appears predominant. Based on in vitro 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.

Effect of Other Drugs on Galantamine

• CYP3A4 Inhibitors:

Ketoconazole

Ketoconazole, a strong inhibitor of CYP3A4 and an inhibitor of CYP2D6, when administered at a dose of 200 mg two times a day for 4 days, increased the AUC of galantamine by 30%.

Erythromycin

Erythromycin, a moderate inhibitor of CYP3A4, when administered at a dose of 500 mg four times a day for 4 days, affected the AUC of galantamine minimally (10% increase).

• CYP2D6 Inhibitors:

A population pharmacokinetics analysis on a database of 852 patients with Alzheimer’s disease showed that the clearance of galantamine was reduced about 25-33% by the concurrent administration of amitriptyline (n=17), fluoxetine (n=48), fluvoxamine (n=14), and quinidine (n=7), all of which are known inhibitors of CYP2D6.

Paroxetine

Paroxetine, a strong inhibitor of CYP2D6, when administered at a dose of 20 mg/day for 16 days, increased the oral bioavailability of galantamine by about 40%.

• H2 Antagonists

Galantamine was administered as a single dose of 4 mg on Day 2 of a 3-day treatment with either cimetidine (800 mg daily) or ranitidine (300 mg daily). Cimetidine increased the bioavailability of galantamine by approximately 16%. Ranitidine had no effect on the pharmacokinetics of galantamine.

• Memantine

Memantine, an N-methyl-D-aspartate receptor antagonist, when administered at a dose of 10 mg two times a day, had no effect on the pharmacokinetics of galantamine (16 mg/day) at steady state.

Effect of Galantamine on Other Drugs

• In Vitro Studies

In vitro studies show that galantamine did not inhibit the metabolic pathways catalyzed by CYP1A2, CYP2A6, CYP3A4, CYP4A, CYP2C, CYP2D6 or CYP2E1. This indicates that the inhibitory potential of galantamine towards the major forms of cytochrome P450 is very low.

• In Vivo Studies

Warfarin

Multiple doses of galantamine at 24 mg/day had no effect on the pharmacokinetics of R- and S-warfarin (administered in a single dose of 25 mg) or on the increased prothrombin time induced by warfarin. The protein binding of warfarin was unaffected by galantamine.

Digoxin

Multiple doses of galantamine at 24 mg/day had no effect on the steady-state pharmacokinetics of digoxin (at a dose of 0.375 mg once daily) when those two drugs were coadministered. In that study, however, one healthy subject was hospitalized on account of 2nd and 3rd degree heart block and bradycardia.

12.5 Pharmacogenomics

CYP2D6 Poor Metabolizers
Approximately 7% of the normal population has a genetic variation that leads to reduced levels of activity of CYP2D6 isozyme. Such individuals have been referred to as poor metabolizers. After a single oral dose of 4 mg or 8 mg galantamine, CYP2D6 poor metabolizers demonstrated a similar Cmax and about 35% AUC∞ increase of unchanged galantamine compared to extensive metabolizers.

A total of 356 patients with Alzheimer’s disease enrolled in two Phase 3 studies were genotyped with respect to CYP2D6 (n=210 hetero-extensive metabolizers, 126 homo-extensive metabolizers, and 20 poor metabolizers). Population pharmacokinetic analysis indicated that there was a 25% decrease in median clearance in poor metabolizers compared to extensive metabolizers. Dosage adjustment is not necessary in patients identified as poor metabolizers as the dose of drug is individually titrated to tolerability.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

In a 24-month oral carcinogenicity study in rats, an increase in endometrial adenocarcinomas was observed at 10 mg/kg/day (4 times the MRHD of 24 mg/day on a mg/m2 basis or 6 times on a plasma exposure [AUC] basis) and 30 mg/kg/day (12 times MRHD on a mg/m2 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/m2 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/m2 and AUC basis).

Galantamine was not carcinogenic in a 6-month carcinogenicity study in transgenic (P 53-deficient) mice at oral doses up to 20 mg/kg/day, or in a 24-month carcinogenicity study in mice at oral doses up to 10 mg/kg/day (equivalent to the MRHD on a plasma AUC basis).

Mutagenesis
Galantamine was negative in a battery of in vitro (bacterial reverse mutation, mouse lymphoma tk, and chromosomal aberration in mammalian cells) and in vivo (mouse micronucleus) genotoxicity assays.

Impairment of Fertility

No impairment of fertility was seen in rats given up to 16 mg/kg/day (7 times the MRHD on a mg/m2 basis) for 14 days prior to mating in females and for 60 days prior to mating in males.

14.1 Study Outcome Measures

In each study, the primary effectiveness of galantamine 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 galantamine 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 galantamine trials was approximately 4.5 units per year.

The ability of galantamine 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.

14.3 Extended-Release Capsules

The efficacy of galantamine extended-release capsules was studied in a randomized, double-blind, placebo-controlled trial which was 6 months in duration and had an initial 4-week dose-escalation phase. In this trial, patients were assigned to one of 3 treatment groups: Galantamine extended-release capsules in a flexible dose of 16 to 24 mg once daily; galantamine tablets in a flexible dose of 8 to 12 mg twice daily; and placebo. The primary efficacy measures in this study were the ADAS-cog and CIBIC-plus. On the protocol-specified primary efficacy analysis at Month 6, a statistically significant improvement favoring galantamine extended-release capsules over placebo was seen for the ADAS-cog, but not for the CIBIC-plus. Galantamine extended-release capsules showed a statistically significant improvement when compared with placebo on the Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, a measure of function, and a secondary efficacy measure in this study. The effects of both galantamine extended-release capsules and galantamine tablets on the ADAS-cog, CIBIC-plus, and ADCS-ADL were similar in this study.