03.04 Meds for Alzheimers

Okay let’s talk about medications used for Alzheimer’s Disease or Alzheimer’s Type Dementia.

There are two main drug classes - NMDA Receptor Blockers which are usually involved in early treatment and Acetylcholinesterase Inhibitors which are used later. But what I want you to understand right away is that no matter what treatment regimen we choose, Alzheimer’s is a progressive disease with NO cure. These medications only serve to slow down progression of the disease.

So the first class of drugs used for Alzheimer's is nmda receptor blockers. One theory of what causes Alzheimer's is that the nmda receptor is overactive. That means that it allows excessive amounts of calcium into the cells which makes the nerve cells overworked, causing them to break down over time. By blocking that receptor we can slow the degeneration of those nerve cells. The most common example of an nmda receptor blocker is memantine or Namenda. Big nursing considerations are that you should not give it with ketamine because it has the same mechanism of action and will cause an increased sedative effect. We also don't want to give with sodium bicarb because it can decrease excretion of the drug from the kidneys which can cause toxicity.

The second class of drugs used for Alzheimer's is cholinesterase Inhibitors, or acetylcholinesterase inhibitors. You may remember from the neuro course that acetylcholine is an important neurotransmitter for many things in the central nervous system including memory. acetylcholinesterase is the enzyme that breaks down acetylcholine. So, by blocking the enzyme we can increase levels of acetylcholine and therefore increase cholinergic activity within the brain. Remember cholinergic activity deals with rest and digest, so everything is slowing down and constricting. So, these are the 3 most common examples and their major considerations. For Donepezil, make sure you watch for bradycardia. Galantamine can cause bronchoconstriction so make sure you’re using caution in patients with asthma. And rivastigmine should be used in caution in sick sinus syndrome, PUD, lung issues, and urinary obstruction because of the cholinergic activity.

So, let’s recap - NMDA antagonists decrease the excessive activity at the NMDA receptor to organize cognition and slow the degeneration of nerve cells. There are also acetylcholinesterase inhibitors, which can also be called parasympathomimetics that will increase acetylcholine activity to help with memory. Just remember this means increased cholinergic activity so we may see digestive upset, bradycardia, and bronchoconstriction. And remember that there is no cure for Alzheimer’s Disease - these meds just help to slow the progression of the disease.

Okay, that’s all for alzheimer’s meds. Make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing!!