Donepezil Pharmacology

On this episode I discuss the pharmacology of donepezil.

Donepezil is an acetylcholinesterase inhibitor. In dementia, that is a deficiency in acetylcholine and donepezil helps preserve this neurotransmitter.

Donepezil can cause weight loss, GI upset, and diarrhea. This is an important monitoring parameter in our dementia patients.

There is the possibility for donepezil to cause bradycardia and insomnia. Keep an eye out for these adverse effects as they can and do happen in real practice.

Anticholinergics are notorious for blunting the effects of donepezil. We must look out for drug interactions from older anticholinergics like diphenhydramine, amitriptyline, and hydroxyzine.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Memantine Pharmacology

Memantine is classified as an NMDA receptor antagonist. Memantine pharmacology is complex as is the pharmacology of any medication working in the brain. This drug can help reduce the activity of glutamate, an excitatory neurotransmitter which can play a role in Alzheimer’s dementia.

Memantine has an extended release dosage form that is dosed once per day compared to twice per day for the immediate release. However, the cost of the extended release is much more expensive, so it is recommended to begin with the immediate release.

Memantine is cleared by the kidney. In patients with reduced kidney function, you must review to assess if the memantine dose needs to be adjusted.

When using memantine or other dementia medications, be sure to look out for medications that can cause dementia type symptoms. CNS depressants like benzodiazepines, sleep medicines, and anticholinergics are all examples of meds that could exacerbate dementia.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!