Memantine Hydrochloride 14 mg Capsule, Extended Release, 90-count

8 USE IN SPECIFIC POPULATIONS

8.1Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of memantine hydrochloride extended-release capsules in pregnant women. Adverse developmental effects (decreased body weight and skeletal ossification) were observed in the offspring of rats administered memantine during pregnancy at doses associated with minimal maternal toxicity. These doses are higher than those used in humans at the maximum recommended daily dose of memantine hydrochloride extended-release capsules [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 Oral administration of memantine (0, 2, 6, or 18 mg/kg/day) to rats during the period of organogenesis resulted in decreased skeletal ossification in fetuses at the highest dose tested.

The higher no-effect dose for adverse developmental effects (6 mg/kg) is 2 times the maximum recommended human daily dose (MRHD) of memantine hydrochloride extended-release capsules (28 mg) on a body surface area (mg/m 2 ) basis. Oral administration of memantine to rabbits (0, 3, 10, or 30 mg/kg/day) during the period of organogenesis resulted in no adverse developmental effects. The highest dose tested is approximately 20 times the MRHD of memantine hydrochloride extended-release capsules on a mg/m 2 basis.

In rats, memantine (0, 2, 6, or 18 mg/kg/day) was administered orally prior to and throughout mating and, in females, through the period of organogenesis or continuing throughout lactation to weaning. Decreased skeletal ossification in fetuses and decreased body weight in pups were observed at the highest dose tested. The higher no-effect dose for adverse developmental effects (6 mg/kg/day) is 2 times the MRHD of memantine hydrochloride extended-release capsules on a mg/m 2 basis.

Oral administration of memantine (0, 2, 6, or 18 mg/kg/day) to rats from late gestation throughout lactation to weaning, resulted in decreased pup weights at the highest dose tested. The higher no-effect dose (6 mg/kg/day) is approximately 2 times the MRHD of memantine hydrochloride extended-release capsules on a mg/m 2 basis.

8.2Lactation Risk Summary There are no data on the presence of memantine in human milk, the effects on the breastfed infant, or the effects of memantine hydrochloride extended-release capsules on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for memantine hydrochloride extended-release capsules and any potential adverse effects on the breastfed infant from memantine hydrochloride extended-release capsules or from the underlying maternal condition.

8.4Pediatric Use Safety and effectiveness in pediatric patients have not been established. Memantine failed to demonstrate efficacy in two 12-week controlled clinical studies of 578 pediatric patients aged 6-12 years with autism spectrum disorders (ASD), including autism, Asperger’s disorder and Pervasive Development Disorder - Not Otherwise Specified (PDD-NOS). Memantine has not been studied in pediatric patients under 6 years of age or over 12 years of age.

Memantine treatment was initiated at 3 mg/day and the dose was escalated to the target dose (weight-based) by week 6. Oral doses of memantine 3, 6, 9, or 15 mg extended-release capsules were administered once daily to patients with weights < 20 kg, 20-39 kg, 40-59 kg and ≥ 60 kg, respectively. In a randomized, 12-week double-blind, placebo-controlled parallel study (Study A) in patients with autism, there was no statistically significant difference in the Social Responsiveness Scale (SRS) total raw score between patients randomized to memantine (n = 54) and those randomized to placebo (n = 53).

In a 12-week responde…

8.1Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of memantine hydrochloride extended-release capsules in pregnant women. Adverse developmental effects (decreased body weight and skeletal ossification) were observed in the offspring of rats administered memantine during pregnancy at doses associated with minimal maternal toxicity. These doses are higher than those used in humans at the maximum recommended daily dose of memantine hydrochloride extended-release capsules [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 Oral administration of memantine (0, 2, 6, or 18 mg/kg/day) to rats during the period of organogenesis resulted in decreased skeletal ossification in fetuses at the highest dose tested.

The higher no-effect dose for adverse developmental effects (6 mg/kg) is 2 times the maximum recommended human daily dose (MRHD) of memantine hydrochloride extended-release capsules (28 mg) on a body surface area (mg/m 2 ) basis. Oral administration of memantine to rabbits (0, 3, 10, or 30 mg/kg/day) during the period of organogenesis resulted in no adverse developmental effects. The highest dose tested is approximately 20 times the MRHD of memantine hydrochloride extended-release capsules on a mg/m 2 basis.

In rats, memantine (0, 2, 6, or 18 mg/kg/day) was administered orally prior to and throughout mating and, in females, through the period of organogenesis or continuing throughout lactation to weaning. Decreased skeletal ossification in fetuses and decreased body weight in pups were observed at the highest dose tested. The higher no-effect dose for adverse developmental effects (6 mg/kg/day) is 2 times the MRHD of memantine hydrochloride extended-release capsules on a mg/m 2 basis.

Oral administration of memantine (0, 2, 6, or 18 mg/kg/day) to rats from late gestation throughout lactation to weaning, resulted in decreased pup weights at the highest dose tested. The higher no-effect dose (6 mg/kg/day) is approximately 2 times the MRHD of memantine hydrochloride extended-release capsules on a mg/m 2 basis.

8.4Pediatric Use Safety and effectiveness in pediatric patients have not been established. Memantine failed to demonstrate efficacy in two 12-week controlled clinical studies of 578 pediatric patients aged 6-12 years with autism spectrum disorders (ASD), including autism, Asperger’s disorder and Pervasive Development Disorder - Not Otherwise Specified (PDD-NOS). Memantine has not been studied in pediatric patients under 6 years of age or over 12 years of age.

Memantine treatment was initiated at 3 mg/day and the dose was escalated to the target dose (weight-based) by week 6. Oral doses of memantine 3, 6, 9, or 15 mg extended-release capsules were administered once daily to patients with weights < 20 kg, 20-39 kg, 40-59 kg and ≥ 60 kg, respectively. In a randomized, 12-week double-blind, placebo-controlled parallel study (Study A) in patients with autism, there was no statistically significant difference in the Social Responsiveness Scale (SRS) total raw score between patients randomized to memantine (n = 54) and those randomized to placebo (n = 53).

In a 12-week responder-enriched randomized withdrawal study (Study B) in 471 patients with ASD, there was no statistically significant difference in the loss of therapeutic response rates between patients randomized to remain on full-dose memantine (n = 153) and those randomized to switch to placebo (n = 158). The overall safety profile of memantine in pediatric patients was generally consistent with the known safety profile in adults [see Adverse Reactions (6.1) ] . In Study A, the adverse reactions in the memantine group (n = 56) that were reported in at least 5% of patients and at least twice the frequency of the placebo group (N = 58) are listed in Table 2.

Table 2: Study A Commonly Reported Adverse Reactions with a Frequency ≥ 5% and Twice That of Placebo Adverse Reaction Memantine N = 56 Placebo N = 58 Cough 8.9% 3.4% Influenza 7.1% 3.4% Rhinorrhea 5.4% 0% Agitation 5.4% 1.7% Discontinuations due to Adverse Reactions a Aggression 3.6% 1.7% Irritability 1.8% 3.4% a Reported adverse reactions leading to discontinuation in more than one patient in either treatment group. The adverse reactions that were reported in at least 5% of patients in the 12-48 week open-label study to identify responders to enroll in Study B are listed in Table 3.

Table 3: 12-48 Week Open Label Lead-In study to Study B Commonly Reported Adverse Reactions with a Frequency ≥ 5% Adverse Reaction Memantine N = 903 Headache 8.0% Nasopharyngitis 6.3% Pyrexia 5.8% Irritability 5.4% Discontinuations due to Adverse Reactions a Irritability 1.2% Aggression 1.0% a At least 1% incidence of adverse reactions leading to premature discontinuation. In the randomized withdrawal study (Study B), the adverse reaction in patients randomized to placebo (n = 160) and reported in at least 5% of patients and twice that of the full-dose memantine treatment group (n = 157) was irritability (5.0% vs 2.5%).

Juvenile Animal Study In a juvenile animal study, male and female juvenile rats were administered memantine (15, 30, and 45 mg/kg/day) starting on postnatal day (PND) 14 through PND 70. Body weights were reduced at 45 mg/kg/day. Delays in sexual maturation were noted in male and female rats at doses ≥ 30 mg/kg/day.

Memantine induced neuronal lesions in several areas of the brain on PND 15 and 17 at doses ≥ 30 mg/kg/day. Behavioral toxicity (decrease percent of auditory startle habituation) was noted for animals in the 45 mg/kg/day dose group. The 15 mg/kg/day dose was considered the No-Observed-Adverse-Effect-Level (NOAEL) for this study.

In a second juvenile rat toxicity study, male and female juvenile rats were administered memantine (1, 3, 8, 15, 30, and 45 mg/kg/day) starting on postnatal day (PND) 7 through PND 70. Due to early memantine-related mortality, the 30 and 45 mg/kg/day dose groups were terminated without further evaluation. Memantine induced apoptosis or neuronal degeneration in several areas of the brain on PND…

8.5Geriatric Use The majority of people with Alzheimer’s disease are 65 years of age and older. In the clinical study of memantine hydrochloride extended-release, the mean age of patients was approximately 77 years; over 91% of patients were 65 years and older, 67% were 75 years and older, and 14% were at or above 85 years of age. The efficacy and safety data presented in the clinical trial sections were obtained from these patients.

There were no clinically meaningful differences in most adverse reactions reported by patient groups ≥ 65 years old and < 65 years old.