Tacrine

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.