Galantamine Oral Solution

Galantamine Oral Solution USP, 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.

Serious adverse reactions are discussed in more detail in the following sections of the labeling:

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 in galantamine-treated patients from double-blind clinical trials (≥5%) 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 3956 galantamine-treated patients who participated in 8 placebo-controlled clinical studies and 1454 subjects 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 Drug Reactions Reported by ≥1% of Galantamine-Treated Patients in Pooled Placebo-Controlled, Double-Blind Clinical Trials

The majority of these adverse events 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=3956) 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=1454) 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=3956) and 56 (2.2%) placebo patients (n=2546) 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=1454) discontinued due to an adverse reaction. Those events with an incidence of ≥0.5% included nausea (43, 3%), 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%).

Postmarketing Experience

The following additional adverse reactions have been identified during post-approval use of galantamine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency:

Immune System Disorders: Hypersensitivity

Psychiatric Disorders: Hallucinations

Nervous System Disorders: Seizures

Ear and Labyrinth Disorders: Tinnitus

Vascular Disorders: Hypertension

Hepatobiliary Disorders: Hepatitis, Increased hepatic enzyme

Skin and Subcutaneous Tissue Disorders: Steven-Johnson syndrome, Acute generalized exanthematous pustulosis, Erythema multiforme

Use with Anticholinergics

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

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)].

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 galantamineoverdosage. Intravenous atropine sulfate titrated to effect is recommended at an initial dose of 0.5 mg to 1 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 co-administered with quaternary anticholinergics. It is not known whether galantamine 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.

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.