Drug Facts: Cognex (tacrine)

August 3, 2010

Generic name: tacrine

Available in 10 mg, 20 mg, 30 mg, and 40 mg capsules.

Why It’s Prescribed
To slow progression of symptoms during the early stages of Alzheimer’s. Because side effects can be severe, however, this drug is now rarely prescribed.

Who Benefits
Provides modest benefits in only about a third of people with mild to moderate Alzheimer’s. The disease will continue to progress despite treatment.

How it Works
Slows the breakdown of acetylcholine, a chemical that aids memory by transmitting messages between brain cells.

Dosage Guidelines
To start: 10 mg, four times a day. The dose may be increased to up to 40 mg four times a day.

Onset of Effect
Benefits, if any, may appear within several weeks of starting the drug.

Store in a tightly sealed container away from heat, moisture and light.

Missed Dose
Take as soon as you remember, or resume your normal schedule if your next dose is within two hours.

Long-term Use
See your doctor for regular tests and exams if you are taking this drug long term. The drug is taken long term and may move the clock back a few months, but the disease continues to progress. If the drug seems to stop working, your doctor may switch you to another Alzheimer’s drug.

Side Effects
Serious: Unsteadiness or clumsiness, severe vomiting, racing or pounding heartbeat, seizures, liver damage.
Most common: Nausea, vomiting.
Less common: Stomach pain or cramps, indigestions, sore or achy muscles, headaches, dizziness, loss of appetite, diarrhea, belching, rapid breathing, flushed skin, increased urination, insomnia, watery eyes or mouth, runny nose, swelling in the legs or feet.

Precautions & Special Concerns
You will need blood tests every couple weeks to check for signs of possible liver damage.

When to Call the Doctor
If you experience side effects or the drug seems to stop working.

In Case of Overdose: Symptoms & What to Do
Profuse sweating or salivation, seizures, muscle weakness, severe nausea or vomiting, rapid and weak pulse, slowed heartbeat, enlarged pupils in the eyes, irregular breathing. Call your doctor, emergency medical services, or poison control center immediately.

Drug Interactions
May interact with cimetidine, anti-inflammatory pain relievers, or theophylline. Antihistamines, antipsychotic drugs, and some drugs for incontinence may also diminish its effects, as may smoking (nicotine).

Food Interactions
No known food interactions. Avoid alcohol if you are taking this drug.

Disease Interactions
Consult your doctor if you have asthma, epilepsy or seizures, heart disease, an ulcer, bowel or liver disease, Parkinson’s disease, urinary tract problems, or have had a head injury.

Expert comment
“For some people with Alzheimer’s disease, this drug can lead to improvements that the family can see. In others, responses may only be detectable under special testing conditions, or there may be no measurable response at all. It is important that family members and physicians maintain realistic expectations for drug therapy and remember that, as with all current Alzheimer’s drugs, responses are generally only modest at best.” –Samuel E. Gandy, M.D., Ph.D., Scientific Advisory Board, Fisher Center for Alzheimer’s Research Foundation


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