Trihexyphenidyl 2mg Tablets

Trihexyphenidyl is a synthetic tertiary amine anticholinergic agent that acts as a muscarinic acetylcholine receptor antagonist. It blocks cholinergic impulses in the central nervous system, particularly in the basal ganglia, thereby reducing the imbalance between acetylcholine and dopamine that contributes to Parkinsonian symptoms. It also exerts some direct antispasmodic effect on smooth muscle.

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Hallucinations (seeing or hearing things that are not there)
Feeling agitated or experiencing a change in behavior
Confusion or memory problems
Difficulty urinating
Rapid heartbeat
Severe constipation or stomach pain, which may indicate a serious bowel problem
Muscle weakness
New or worsening trouble controlling body movements
Changes in vision, eye pain, or severe eye irritation
Fever
Inability to sweat during physical activity or in warm temperatures
Enlarged pupils
Neuroleptic malignant syndrome (NMS), a rare but potentially deadly condition that can occur when this medication is stopped suddenly or the dose is lowered. Symptoms of NMS include:
+ Fever
+ Muscle cramps or stiffness
+ Dizziness
+ Severe headache
+ Confusion or changes in thinking
+ Rapid or abnormal heartbeat
+ Excessive sweating

Other Possible Side Effects

Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:

Dizziness or drowsiness
Upset stomach or vomiting
Constipation
Headache
Dry mouth
Feeling nervous or excitable

This is not an exhaustive list of possible side effects. If you have questions or concerns, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced.
If you have been diagnosed with narrow-angle glaucoma.
* If you have a history of tardive dyskinesia, a severe muscle disorder.

This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe to take this medication in conjunction with your other treatments and health issues. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

Before operating a vehicle or engaging in any activity that requires your full attention, wait until you understand how this medication affects you. It is also crucial to discuss the use of alcohol, marijuana, or other forms of cannabis, as well as prescription or over-the-counter (OTC) medications that may cause drowsiness, with your doctor beforehand.

Do not abruptly discontinue this medication without first consulting your doctor, as this may increase your risk of experiencing side effects. If it becomes necessary to stop taking this drug, your doctor will provide guidance on how to gradually taper off the medication to minimize potential risks.

Patients with narrow-angle glaucoma should be aware that this condition may lead to vision loss. It is vital to consult with your doctor regarding this potential risk. Additionally, adhere to your doctor's recommendations for regular eye pressure checks and vision tests.

There is a risk of heat stroke associated with this medication, particularly in hot weather or during physical activity. Therefore, it is crucial to exercise caution and stay hydrated. If you are 60 years or older, use this medication with caution, as you may be more susceptible to side effects.

If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is essential to discuss the potential benefits and risks of this medication to both you and your baby to make an informed decision.

• Other anticholinergic agents (e.g., atropine, scopolamine, benztropine, antihistamines like diphenhydramine, tricyclic antidepressants, phenothiazines): Increased risk of severe anticholinergic effects (e.g., paralytic ileus, urinary retention, heat stroke, confusion, hallucinations).
• Potassium chloride (oral solid formulations): Increased risk of gastrointestinal lesions due to delayed gastric emptying.

• CNS depressants (e.g., alcohol, opioids, benzodiazepines, sedatives): Additive CNS depression (drowsiness, dizziness).
• Metoclopramide: Antagonism of prokinetic effect.
• Dopamine agonists (e.g., levodopa): May enhance dyskinesias or psychiatric side effects in some patients, though often used concomitantly in Parkinson's disease.
• Antacids/Adsorbent antidiarrheals: May reduce absorption of trihexyphenidyl if given concurrently.

• Dry mouth
• Blurred vision
• Constipation
• Urinary retention
• Dizziness
• Drowsiness
• Nausea
• Nervousness
• Confusion
• Hallucinations
• Agitation
• Tachycardia
• Heat intolerance/reduced sweating

Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal studies have shown adverse effects, but there are no adequate and well-controlled studies in pregnant women.

Trihexyphenidyl is excreted into breast milk. Use is generally not recommended due to potential for anticholinergic effects in the infant (e.g., sedation, constipation, urinary retention) and potential for decreased milk supply in the mother.

Safety and efficacy have not been established in pediatric patients. Use is generally not recommended.

Elderly patients are more susceptible to the anticholinergic side effects of trihexyphenidyl, including confusion, hallucinations, memory impairment, urinary retention, and constipation. Start with lower doses and titrate slowly. Monitor closely for CNS and peripheral anticholinergic effects. Avoid in patients with cognitive impairment or dementia.

• Trihexyphenidyl is particularly effective for reducing tremor and rigidity in Parkinson's disease, but less effective for bradykinesia.
• It is commonly used to manage drug-induced extrapyramidal symptoms (EPS) caused by antipsychotics, especially dystonia and akathisia.
• Due to its anticholinergic properties, it should be used with extreme caution or avoided in patients with narrow-angle glaucoma, prostatic hypertrophy, urinary retention, or gastrointestinal obstruction.
• Patients should be advised about the risk of anhidrosis and heat stroke, especially during hot weather or strenuous activity.
• Abrupt discontinuation can lead to withdrawal symptoms, including worsening of Parkinsonian symptoms, anxiety, and insomnia. Taper gradually.
• Cognitive impairment and hallucinations are significant concerns, especially in the elderly; monitor closely and consider dose reduction or discontinuation if these occur.

• Other anticholinergic agents (e.g., benztropine, procyclidine)
• Dopamine agonists (e.g., pramipexole, ropinirole, rotigotine) for Parkinson's disease
• Levodopa/carbidopa for Parkinson's disease
• Amantadine for Parkinson's disease and drug-induced EPS
• Beta-blockers (e.g., propranolol) for tremor
• Benzodiazepines (e.g., lorazepam) for acute dystonia or akathisia (drug-induced EPS)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more details. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide information about the medication taken, the amount, and the time it happened.