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Generic Name: Tacrine
Brand Name(s):
Information updated: April 1, 2000
Overview
Although Cognex is by no means a brand-new drug, it has only recently been
approved for the treatment of Alzheimer's disease.
This medication is
not a cure, and not all patients respond well.
For some, however, Cognex
can slow the mental deterioration associated with this dread disease.
A
smaller proportion, perhaps 5 or 10 percent, may experience dramatic
improvement.
These individuals may regain the ability to recognize
family members or to participate in the daily life of the family, feeding and
dressing themselves, for example. Such improvements, while not permanent, are
usually welcome.
Side Effects and Interactions
Cognex can cause a number of side effects which
are more common at higher doses.
The most common include elevated liver
enzymes, nausea and vomiting, diarrhea, muscle aches, loss of appetite, and
trouble walking.
Chills, fever, nervousness, fainting, headache,
dizziness, swelling of the feet and legs, excessive sweating and increased
urination have also been reported.
Slower heart rate, increased stomach
acid, breathing difficulties and convulsions could cause special problems in
people with pre-existing conditions such as heart disease, ulcers, asthma or
epilepsy.
Notify the doctor immediately if the patient develops a rash,
yellow eyes or skin, very pale or black tarry stools, or if vomiting of material
resembling coffee grounds occurs. These could indicate a serious adverse
reaction.
If a person on Cognex needs an operation, be sure to tell the
surgeon about the medication, as it could alter the response to drugs used in
surgery.
Cognex slows the body's elimination of the asthma drug
theophylline and blood levels can double. If both drugs are needed, the doctor
should monitor theophylline blood levels and adjust the dose if
necessary.
Any gastrointestinal side effects should be treated
cautiously, as some common stomach medicines, such as Pro-Banthine, are likely
to interact with Cognex.
In addition, Tagamet can increase the amount of
Cognex circulating in the body.
Because Cognex has not been widely
prescribed for very long, there may be other drug interactions that have not yet
been identified.
Capsaicin (cayenne) inhibits liver enzymes (CYP1A2) and
thus slows the metabolism of Cognex.
Ask your doctor and pharmacist to
check whether any other drug or herb you are taking is safe in combination with
Cognex.
Special Precautions
Response to Cognex seems to improve as the dose increases. Some individuals cannot tolerate Cognex, however, especially at higher doses.
Reversible liver enzyme elevations have occurred.
Patients on Cognex should have liver function monitored on a regular basis.
People with liver problems may require closer supervision.
Taking the Medicine
Because food reduces the absorption of Cognex, the medicine should be taken on an empty stomach
(one hour before meals or two hours after).
It is best taken at the same time each day to
maintain consistent blood levels.
Discontinuing this medicine abruptly may worsen the
patient's condition noticeably, so if the medicine must be stopped check with the doctor about how to withdraw gradually.
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Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio.
© 2000