April 28, 2017
Recommended Topic Related To:


"Oct. 17, 2012 -- Extreme agitation, aggressiveness, and psychosis are common among people with Alzheimer's disease -- especially in its later stages -- and they are among the symptoms most often associated with admission to nursing homes.



(tacrine hydrochloride) Capsules, USP


Cognex® (tacrine hydrochloride) is a reversible cholinesterase inhibitor, known chemically as 1,2,3,4-tetrahydro-9-acridinamine monohydrochloride monohydrate. Tacrine hydrochloride is commonly referred to in the clinical and pharmacological literature as THA. It has an empirical formula of C13H14N2•HCl•H2O and a molecular weight of 252.74.

The molecular formula of tacrine hydrochloride is:

Cognex® (Tacrine Hydrochloride) Structural Formula Illustration

Tacrine hydrochloride is a white solid and is freely soluble in distilled water, 0.1N hydrochloric acid, acetate buffer (pH 4.0), phosphate buffer (pH 7.0 to 7.4), methanol, dimethylsulfoxide (DMSO), ethanol, and propylene glycol. The compound is sparingly soluble in linoleic acid and PEG 400.

Each capsule of Cognex® contains tacrine as the hydrochloride. Inactive ingredients are hydrous lactose, magnesium stearate, and microcrystalline cellulose. The hard gelatin capsules contain gelatin, NF; silicon dioxide, NF; sodium lauryl sulfate, NF; and the following dyes: 10 mg: D&C Yellow #10, FD&C Green #3, titanium dioxide; 20 mg: D&C Yellow #10, FD&C Blue #1, titanium dioxide; 30 mg: D&C Yellow #10, FD&C Blue #1, FD&C Red #40, titanium dioxide; 40 mg: D&C Yellow #10, FD&C Blue #1, FD&C Red #40, D&C Red #28, titanium dioxide.

Each 10-, 20-, 30-, and 40-mg Cognex® (tacrine) capsule for oral administration contains 12.75, 25.50, 38.25, and 51.00 mg of tacrine HCl, respectively.

What are the possible side effects of tacrine (Cognex)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • confusion, hallucinations;
  • extreme or sudden changes in behavior;
  • seizure (convulsions);
  • pain or burning when you urinate; or
  • nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects of tacrine...

Read All Potential Side Effects and See Pictures of Cognex »

What are the precautions when taking tacrine (Cognex)?

Consult your...

Read All Potential Precautions of Cognex »

Last reviewed on RxList: 4/18/2017
This monograph has been modified to include the generic and brand name in many instances.

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

WebMD Daily

Get breaking medical news.