| Indication |
For the treatment of mild to moderate dementia of the Alzheimer's
type. Has also been investigated in patients with mild cognitive
impairment who did not meet the diagnostic criteria for Alzheimer's
disease. |
| Pharmacodynamics |
Galantamine is a parasympathomimetic, specifically, a reversible
cholinesterase inhibitor. It is indicated for the treatment of mild to
moderate dementia of the Alzheimer's type. An early pathophysiological
feature of Alzheimer's disease that is associated with memory loss and
cognitive deficits is a deficiency of acetylcholine as a result of
selective loss of cholinergic neurons in the cerebral cortex, nucleus
basalis, and hippocampus. Galantamine 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 acetylcholinesterase. If this
proposed mechanism of action is correct, Galantamine's effect may
lessen as the disease progresses and fewer cholinergic neurons remain
functionally intact. There is no evidence that Galantamine alters the
course of the underlying dementing process. |
| Mechanism of action |
Galantamine is a phenanthrene alkaloid and a reversible,
competitive acetylcholinesterase inhibitor. It is not structurally
related to other acetylcholinesterase inhibitors. Galantamine's proposed
mechanism of action involves the reversible inhibition of
acetylcholinesterase, which prevents the hydrolysis of acetycholine,
leading to an increased concentration of acetylcholine at cholinergic
synapses. Galantamine also binds allosterically with nicotinic
acetylcholine receptors and may possibly potentiate the action of
agonists (such as acetylcholine) at these receptors. |
| Absorption |
Not Available |
| Volume of distribution |
|
| Protein binding |
18% |
| Metabolism |
Not Available |
| Route of elimination |
Galantamine is metabolized by hepatic cytochrome P450 enzymes, glucuronidated, and excreted unchanged in the urine. |
| Half life |
7 hours |
| Clearance |
- 300 mL/min [After IV. or oral administration]
|
| Toxicity |
LD50=75 mg/kg (rat) |
