Name: Tacrine

Side effects

Common Adverse Events Leading to Discontinuation

In clinical trials, approximately 17% of the 2706 patients who received Cognex® (tacrine) and 5% of the 1886 patients who received placebo withdrew permanently because of adverse events. It should be noted that some of the placebo-treated patients were exposed to Cognex® (tacrine) prior to receiving placebo due to the variety of study designs used, including crossover studies. Transaminase elevations were the most common reason for withdrawals during Cognex® (tacrine) treatment (8% of all Cognex® (tacrine) -treated patients, or 212 of 456 patients withdrawn). The controlled clinical trial protocols required that any patient with an ALT/SGPT elevation > 3 X ULN be withdrawn, because of concern about potential hepatotoxicity. Apart from withdrawals due to transaminase elevations, 244 patients (9%) withdrew for adverse events while receiving Cognex® (tacrine) .

Other adverse events that most frequently led to the withdrawal of tacrine-treated patients in clinical trials were nausea and/or vomiting (1.5%), agitation (0.9%), rash (0.7%), anorexia (0.7%), and confusion (0.5%). These adverse events also most frequently led to the withdrawal of placebo-treated patients, although at lower frequencies (0.1% to 0.2%).

Most Frequent Adverse Clinical Events Seen in Association With the Use of Tacrine

The events identified here are those that occurred at an absolute incidence of at least 5% of patients treated with Cognex® (tacrine) , and at a rate at least 2-fold higher in patients reated with Cognex (tacrine) ®than placebo.

The most common adverse events associated with the use of Cognex® (tacrine) were elevated transaminases, nausea and/or vomiting, diarrhea, dyspepsia, myalgia, anorexia, and ataxia. Of these events, nausea and/or vomiting, diarrhea, dyspepsia, and anorexia appeared to be dose-dependent.

Adverse Events Reported in Controlled Trials

The events cited in the tables below reflect experience gained under closely monitored conditions of clinical trials with a highly selected patient population. In actual clinical practice or in other clinical trials, these frequency estimates may not apply, as the conditions of use, reporting behavior, and the kinds of patients treated may differ.

Table 3 lists treatment-emergent signs and symptoms that occurred in at least 2% of patients with Alzheimer's disease in placebo-controlled trials and who received the recommended regimen for dose introduction and titration of Cognex® (see DOSAGE AND ADMINISTRATION).

Table 3. Adverse Events Occurring in at Least 2% of Patients Receiving Cognex® (tacrine) at a Starting Dose of 40 mg/day with Titration in 40 mg/day Increments Every 6 Weeks in Controlled Clinical Trials [Number (%) of Patients]

Adverse Events
N = 634
N = 342
  Elevated Transaminasea 184 (29) 5 (2)
  Headache 67 (11) 52 (15)
  Fatigue 26 (4) 9 (3)
  Chest Pain 24 (4) 18 (5)
  Weight Decrease 21 (3) 4 (1)
  Back Pain 15 (2) 14 (4)
  Asthenia 15 (2) 7 (2)
  Nausea and/or Vomiting 178 (28) 29 (9)
  Diarrhea 99 (16) 18 (5)
  Dyspepsia 57 (9) 22 (6)
  Anorexia 54 (9) 11 (3)
  Abdominal Pain 48 (8) 24 (7)
  Flatulence 22 (4) 5 (2)
  Constipation 24 (4) 8 (2)
  Purpura 15 (2) 8 (2)
  Myalgia 54 (9) 18 (5)
  Dizziness 73 (12) 39 (11)
  Confusion 42 (7) 24 (7)
  Ataxia 36 (6) 12 (4)
  Insomnia 37 (6) 18 (5)
  Somnolence 22 (4) 11 (3)
  Tremor 14 (2) 2 (

Tacrine and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Tacrine falls into category C:

In animal studies, pregnant animals were given this medication and had some babies born with problems. No well-controlled studies have been done in humans, though. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.


There are no well-controlled studies that have been done in pregnant women. Tacrine should be used during pregnancy only if the possible benefit outweighs the possible risk to the unborn baby.


No studies have been done in animals, and no well-controlled studies have been done in pregnant women. Tacrine should be given to a pregnant woman only if clearly needed.

Tacrine Dosage

Take tacrine exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The Tacrine dose your doctor recommends will be based on the following (use any or all that apply):

  • the condition being treated
  • other medical conditions you have
  • other medications you are taking
  • how you respond to this medication
  • your weight
  • your height
  • your age
  • your gender

Tacrine is available in the following doses:

  • Tacrine 10 Mg Oral Capsule
  • Tacrine 20 Mg Oral Capsule
  • Tacrine 30 Mg Oral Capsule
  • Tacrine 40 Mg Oral Capsule

Uses For tacrine

Tacrine is used to treat the symptoms of mild to moderate Alzheimer's disease. Tacrine will not cure Alzheimer's disease, and it will not stop the disease from getting worse. However, tacrine can improve thinking ability in some patients with Alzheimer's disease.

In Alzheimer's disease, many chemical changes take place in the brain. One of the earliest and biggest changes is that there is less of a chemical messenger called acetylcholine (ACh). ACh helps the brain to work properly. Tacrine slows the breakdown of ACh, so it can build up and have a greater effect. However, as Alzheimer's disease gets worse, there will be less and less ACh, so tacrine may not work as well.

Tacrine may cause liver problems. While taking tacrine, you must have blood tests regularly to see if the medicine is affecting your liver.

tacrine was available only with your doctor's prescription. Tacrine (Cognex®) was withdrawn from the US market in May 2012.