Doctors typically perform liver blood tests before prescribing Alzheimer's medications. Since Alzheimer's is a disease of the brain, a patient and his family may wonder why these tests are necessary. But as with other systemic medications, it's impossible to target Alzheimer's medicines directly at the brain. They affect other body functions, too, especially the liver.
History
Alzheimer's is a disease of old age characterized by dementia including memory loss as well as cognitive and personality changes. Diagnosis is made by taking a medical history, performing psychological and neurological exams as well as other laboratory tests, and by eliminating other causes for the symptoms. Treatments are aimed at minimizing symptoms, and at best only slow the progress of the disease.
Significance
The cause of Alzheimer's is not understood, but the disease is recognized postmortem by protein deposits in the brain. Therefore, medications have been developed that attempt to address the build up of protein plaque directly, in hopes that this will benefit Alzheimer's patients by slowing progress of the disease. Drugs that are thought to interfere with the build-up of protein plaque act within the liver, altering liver function and being metabolized by the liver at the same time.
Features
The liver performs several metabolic functions in the body. Primarily, it stores energy and filters toxins from the blood stream so they can be excreted. Toxins can be byproducts from normal body functions, or they may be substances that are ingested. Ingested toxins might be normal constituents of food, added food chemicals, recreational drugs like alcohol, or therapeutic drugs including prescriptions, over-the-counter medications and herbal supplements.
Function
Since liver function is altered by Alzheimer's medications, blood tests to measure liver enzymes are needed before drugs are prescribed. The initial blood test reveals the over all health of the liver and provides a baseline for comparing future blood test results. Liver enzymes within normal limits to let the doctor know that the patient is not suffering liver damage as a result of the medication. Liver function is monitored periodically as long as the patient is on medication.
Considerations
Other medications can also interfere with liver function and, consequently, interfere with Alzheimer's medication. A patient's family must make sure the doctor is aware of all medications, both over the counter and prescription, that the patient is taking. Herbal or vitamin supplements may also contain chemicals that interfere with prescribed drugs and should be reported to the doctor.
Prevention/Solution
If liver blood tests reveal abnormal liver enzyme levels during the course of the patient's treatment, the medication may be discontinued. Liver function usually returns to normal within several weeks of discontinuing the medication. Of course, more blood tests will be needed to follow the patient's recovery.
Potential
Some Alzheimer's medications are significantly more toxic to the liver than others and necessitate more frequent blood testing. Arguments are made that these medications are too risky and the potential benefits too minimal or unproven to make them worth prescribing. But others in the Alzheimer's community feel that since Alzheimer's is inevitably fatal and the course of the disease so devastating, current Alzheimer's patients may suffer more if potentially helpful drugs are withheld while awaiting further testing.
Tags: interfere with, Alzheimer medications, blood tests, Alzheimer disease, Alzheimer patients, blood test, body functions