There are several pharmaceutical options for patients suffering from dementia, including those that seek to improve neurotransmitter functions in the brain. Cholinesterase inhibitors, a family of drugs that attempt to increase the volume and activity of neurotransmitters; can help improve memory, thought and judgment in patients in the early to moderate stages of degenerative dementia.

What Are Cholinesterase Inhibitors?

Cholinesterase inhibitors, also known as acetylcholinesterase inhibitors (AChEI), are chemical compounds that prevent the acetylcholinesterase enzymes from serving their function of breaking down acetylcholine, an important neurotransmitter. This preventative action increases the activity levels and duration of acetylcholine.

AChEIs are found in many natural poisons, venoms and insecticides. These kinds of inhibitors have been harnessed as medicines and made pharmaceutically available for the treatment of not only dementia, but also as antidotes and glaucoma treatment. Examples of cholinesterase inhibitors include Donepezil (branded as Aricept), Galantamine (branded as Reminyl) and Rivastigmine (branded as Exelon).

How Do Cholinesterase Inhibitors Treat Dementia?

Alzheimer's disease and other forms of degenerative dementia have shown a decreased level of activity in the neurotransmitter acetylcholine, which is key to several neurological processes including memory, judgment and thought. Cholinesterase inhibitors serve multiple functions—primarily to increase concentrations of this neurotransmitter in the brain, and also to promote communication between them.

In cases of early to moderate degenerative dementia, these drugs have proven effective in improving cognitive functions in the average patient. However, these effects vary from patient to patient; some show signs of improvement, some remain in the state of when the medicine was first used and others show continued signs of deterioration.

When used in treating dementia, cholinesterase inhibitors need to go through a titration phase—a dosage that is increased gradually to minimize the possible side effects, by building up a steady tolerance to them. If a patient stops taking the drug, within four to six weeks, they will gradually deteriorate to the level of someone who had not taken the drug.

Possible Side Effects

Unfortunately, cholinesterase inhibitors do carry some side effects, both minor and severe. Successful titration of the drug may help reduce or possibly prevent some of these side effects, but the risks still exist. The three most common side effects are nausea, vomiting and diarrhea, especially in the first few weeks. Other side effects include:

  • Trouble with vision
  • Dizziness, fainting spells and frequent stumbling or falling
  • Incontinence, or an increased urge to urinate
  • Nervousness, irritability or acute confusion
  • Skin irritation or hives
  • A lowered pulse or labored breathing
  • Severe stomach pain
  • Short, jerky movements
  • Unusual bruising or bleeding
  • Indigestion and/or lack of appetite
  • Joint pain

Be sure to understand these side effects thoroughly, and consult a medical professional if any become severe.

As long as you are aware of the side effects, and gradually increase the dosage under your physician's direction, cholinesterase inhibitors can be a valuable pharmaceutical treatment for early stages of dementia. By promoting the activity of the neurotransmitter acetylcholine, patients can experience improved thought, boosted mood and a higher sense of judgment and awareness.