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Cogentin Side Effects

Generic name: benztropine

Medically reviewed by Last updated on Oct 3, 2023.

Note: This document contains side effect information about benztropine. Some dosage forms listed on this page may not apply to the brand name Cogentin.

Applies to benztropine: oral tablet. Other dosage forms:

Serious side effects of Cogentin

Along with its needed effects, benztropine (the active ingredient contained in Cogentin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking benztropine:

Incidence not known

Get emergency help immediately if any of the following symptoms of overdose occur while taking benztropine:

Symptoms of overdose

Other side effects of Cogentin

Some side effects of benztropine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

For Healthcare Professionals

Applies to benztropine: compounding powder, injectable solution, oral tablet.


Adverse reactions are anticholinergic in nature and include dry mouth, constipation, tachycardia, and blurred vision.[Ref]

Nervous system

Frequency not reported: Numbness of fingers[Ref]


Frequency not reported: Toxic psychosis, including confusion, disorientation, memory impairment, visual hallucinations, exacerbation of preexisting psychotic symptoms, nervousness, depression[Ref]


Frequency not reported: Constipation, dry mouth, nausea, vomiting, paralytic ileus[Ref]


Frequency not reported: Blurred vision, dilated pupils[Ref]


Frequency not reported: Tachycardia[Ref]


Frequency not reported: Urinary retention, dysuria[Ref]


Frequency not reported: Allergic reaction[Ref]


Frequency not reported: Heatstroke, hyperthermia, fever[Ref]


Frequency not reported: Skin rash[Ref]


1. (2001) "Product Information. Cogentin (benztropine)." Merck & Co., Inc

2. Cerner Multum, Inc. "Australian Product Information."

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.