Cogentin improves muscle control and has been shown to decrease rigidity and tremors associated with Parkinson’s disease. It is also sometimes used to treat people with bipolar disorder who have developed parkinsonism. Cogentin comes in 0.5, 1, and 2 mg tablets to be taken orally, usually at bedtime, and in some cases, an injection is provided. One dose per day will typically suffice to treat symptoms of parkinsonism. Your doctor may start you on a small dose to see how you respond. 

Uses

Medications often used to treat bipolar disorder, such as typical and atypical antipsychotic drugs, may cause drug-induced parkinsonism, the medical term for symptoms that mimic Parkinson’s disease. Drug-induced parkinsonism may cause: 

A decrease in facial expressionsDifficulty starting and controlling movementSlowed movementSoft voiceStiffness of the trunk, arms, or legsTremor

Before Taking

Before prescribing Cogentin, your doctor will evaluate your symptoms and any co-occurring medical conditions that may be affected by the use of this medication. They will also consider the other medications that you are currently taking before deciding if Cogentin is the right choice for your needs. 

Precautions and Contraindications

Cogentin may interact with certain drugs, including antidepressants, sleeping pills, painkillers, antihistamines, anti-diarrheal medications, some antacids, and other medications. It’s important that you speak with your doctor about any potential interactions. This includes telling your doctor about any supplements, herbs, or vitamins that you might also be taking. They may interact with the medication or might change the way the drug works in your body.

Other Anticholinergics

In addition to Cogentin, Artane (trihexyphenidyl) may also be prescribed to treat parkinsonism. Artane is available in tablet and liquid elixir forms. Be sure to tell your doctor if you are currently taking another anticholinergic medication.

Dosage

Your doctor will often start you at a lower dose and may gradually increase this dose to achieve the desired effect. Treatment is often initiated at a low dose and increased by 0.5 mg increments every five to six days until reaching a dose that provides optimal relief without excess side effects. A typical dose for adults is 1 to 4 mg once or twice per day. You should always take only the amount that your doctor has prescribed. Your specific dosage will depend on your needs, age, and weight. The timing of the dosage may also vary depending on your individual needs. For some individuals, a full dose taken right before bed produces the best results. Others find that they need a divided dose taken at different points during the day to help manage their symptoms. If you miss a dose, take it as soon as you remember unless it is almost time for your next dose. If that is the case, simply skip the missed dose. Do not take two doses at once.

Overdose

If you or a loved one have potentially overdosed on Cogentin, call your local poison control center and/or 911 immediately. Symptoms of overdose include:

Clumsiness or unsteadiness Severe drowsiness  Severe dryness of mouth, nose, or throat Fast heartbeat Hallucinations (seeing, hearing, or feeling things that are not there) Mood or mental changes Seizures Shortness of breath or troubled breathing Trouble sleeping Warmth, dryness, and flushing of the skin

Other Cogentin side effects not listed above may also occur in some patients. If you notice any other side effects, be sure to check with your doctor.

Modifications

Cogentin is not recommended for children below the age of three. For kids ages three and up, the use and dose must be determined by the child’s doctor, but the recommended daily dose is 0.02-0.05 milligram per kilogram of body weight.  Caution should be used when prescribing to older adults, since it may produce bladder, bowel, and central nervous system effects.

How to Take and Store

Cogentin tablets are taken by mouth either once a day as a single dose at bedtime or two to four times a day with meals. This medication should also be taken at least one hour before taking an antacid or anti-diarrhea medication, which may affect how Cogentin is absorbed. If you are taking Cogentin to treat extrapyramidal symptoms associated with the use of antipsychotics, your doctor may instruct you to take it on a regular schedule or to only take it as needed. The medication may cause sleepiness or dizziness. Do not drive or operate machinery until you determine how the medication will affect you.  Cogentin should be stored at room temperature in a closed container. It should be kept away from direct sunlight, moisture, heat, and freezing temperatures. 

Side Effects 

The following are common side effects of ​Cogentin. You should check with your doctor if they don’t go away or worsen:

Common

Blurred vision Constipation Decreased sweatingDifficult or painful urination (especially in older men)DrowsinessDryness of mouth, nose, or throat

The following are less common side effects of Cogentin. 

Dizziness or lightheadedness when getting up from a lying down or sitting positionEuphoriaHeadacheMemory impairments (especially in the elderly)NervousnessStomach upset or painUnusual excitement

Severe

Notify your doctor immediately if you experience any of the above rare side effects of Cogentin, as well as these below:

ConfusionEye painSkin rashRapid heart rateHallucinations

Warnings and Interactions

Cogentin can also lead to serious health issues as well as drug interactions. This include:

Allergic Reaction

Allergic reactions may be mild or serious. Mild reactions include skin rashes that may go away if the dosage is decreased. Severe reactions can include swelling of the face and throat, trouble breathing, and hives. If you have a reaction, call your doctor or seek emergency services if symptoms are severe.

Heat Stroke

Cogentin can interfere with the body’s ability to sweat and cool down. This can increase the risk for heat stroke, particularly when it is very hot outside. Staying well-hydrated and avoiding excessive sun exposure may help.

Mental Health Effects

This medication may also lead to symptoms of confusion, excitement, or hallucinations. These risks tend to be more serious in older adults, people who are taking larger doses of Cogentin, and people with a history of mental health conditions.

Muscle Weakness

People who take higher doses of Cogentin may be more likely to experience symptoms of muscle weakness. If you experience this symptom, talk to your doctor about lowering your dose.

Drug Interactions

Cogentin can also interact with a variety of medications and supplements. Taking this medication while using alcohol or other CNS depressants will lead to increased drowsiness. Other medications that may interact with Cogentin include tricyclic antidepressants and haloperidol. Brisbane (AU): Codon Publications; 2018. doi: 10.15586/codonpublications.parkinsonsdisease.2018.ch9