Extended-Release Orphenadrine Citrate Tablets - Managing Muscle Pain and Spasms with Ease

Overview:

Orphenadrine citrate ER (extended-release) tablet is a muscle relaxant used to treat various musculoskeletal pains and conditions. It is the citrate salt of Orphenadrine (2-dimethylamino ethyl-2-methyl benzhydryl ether citrate), which is a crystalline white-colored powder with a bitter taste. This drug shows restricted solubility in water but is slightly soluble in alcohol. It is mainly odorless. The drug is often an available adjunct in Ibuprofen, Aspirin, Codeine, Caffeine, and Paracetamol. Orphenadrine citrate ER tablets (100 mg) were approved by the FDA (Food and Drug Administration) on January 29, 1999, as a muscle relaxant for use in treating pain and discomfort caused by musculoskeletal conditions. The article provides detailed information about this drug.

Uses of Orphenadrine Citrate ER Tablets:

Orphenadrine citrate ER (extended-release) tablets are used for the treatment of muscle pain or spasms, as an adjunct to other medications, physical therapy, and rest, for relief from various musculoskeletal conditions.

Dose and Administration

Orphenadrine citrate ER tablets:

For adults - The recommended drug dosage is two tablets, each of 100 mg (milligram), twice a day, that is, one tablet in the morning and the second one in the evening.

Uses In Specific Population

Pediatric Use: The safety and effectiveness of Orphenadrine are not yet established in pediatric patients. Therefore the drug is not recommended for young children below the age of 12.

Geriatric Use: The drug can cause anticholinergic reactions; it should be cautiously prescribed to elderly people, starting from a lesser dosage initially to avoid adverse effects.

Pregnancy: There is no clinical study conducted to evaluate its effect on reproduction and no controlled data on drug safety and effectiveness in the human population. Also, the limited studies conducted on animal population shows the occurrence of fetal damage. Therefore the drug should not be prescribed to pregnant women. In case of emergency needs, the potential risks and benefits of the drug, along with the person’s need for the drug should be thoroughly evaluated.

Breastfeeding: There is no data present on whether the drug is excreted into human milk or animal milk. Also, there is no information about the effects of this drug on breastfed infants and the production of milk. Therefore, Orphenadrine should be cautiously prescribed by considering the health and developmental benefits of the infant, the clinical needs of the mother for Orphenadrine, and also the potential side effects of the drug and underlying maternal condition on the infant.

For Patients:

Why Are Orphenadrine Citrate ER Tablets Prescribed?

Orphenadrine citrate ER (extended-release) tablets are used for the treatment of muscle pain or spasms along with other treatments, including physical therapy and rest. The drug helps to get rid of the discomfort and pain caused by sprains, strains, and other injuries to the muscles. This drug belongs to a class of medication known as skeletal muscle relaxants, and it works by altering the perception of pain felt by the body.

How Should the Drug Be Used?

The drug is available as a long-acting or extended-release tablet that can be taken through the mouth. The drug is usually prescribed by the doctor to be taken twice a day and at the same time every day. A person should carefully read all the directions given on the label or prescription, and they must ask the pharmacist or doctor if they do not understand any part of the instructions. Also, a person should not alter the drug dosage without consulting a doctor and thus should take it as directed. It should be taken in exact dosage and frequency, as prescribed by the doctor.

What Precautions Should Be Taken Before Taking this Drug?

The following precautions must be taken before taking Orphenadrine citrate ER tablets:

• The doctor must be informed about any allergic reactions to this drug or any other medication or any ingredients present in Orphenadrine or extended-release tablets.

• A person should also inform the doctor about all the non-prescription and prescription drugs that they are taking or are planning to take. These include nutritional supplements, herbal products, vitamins, sleeping pills and sedatives, medication for depression, or medications for colds and allergies.

• The doctor must also be informed if a person is pregnant, planning to get pregnant, breastfeeding, or becoming pregnant during the treatment with Orphenadrine.

• The person should also inform the doctor about their past or present medical history, if any, such as if they have or have ulcers, glaucoma, myasthenia gravis, intestinal or urinary tract blockage, irregular heartbeat, kidney or liver disease, and enlarged prostate.

• In case a person is planning to undergo any minor or major surgery, they must inform the doctor about taking Orphenadrine.

• If a person is 65 years or older, they must ask the doctor about the benefits and risks of taking Orphenadrine, as it is not safe for older people, and therefore they should not usually take this medication. Other medications used to treat the same condition are considered much safer for these patients.

• The drug is also known to make a person drowsy. Therefore, one must avoid driving a vehicle or operating heavy machinery while taking this medication unless they are aware of how the drug affects them.

• A person consuming alcohol must also consult with the doctor about the safe use of alcohol with Orphenadrine, as the side effects from the drug become more severe with alcohol.

What Are the Side Effects of the Drug?

Common Side Effects:

• Drowsiness.

• Constipation.

• Dry mouth.

• Vomiting.

• Blurred vision.

• Upset stomach.

• Headache.

• Blurred vision.

• Dizziness.

• Difficulty urinating.

Severe Side Effects:

• Fainting.

• Skin rash.

• Irregular or fast heartbeat.

• Confusion.

• Hallucinations.

Overdose:

In case of an intentional or accidental drug overdose, the poison control department must be contacted, and if a person has troubled breathing, collapses, or has seizures, then emergency medical help must be availed immediately.

The treatment of drug overdose from Orphenadrine includes intensive monitoring, evacuation or cleaning away of stomach content if necessary, charcoal therapy at repeated doses, and necessary supportive treatment for any adverse reactions.

Missed Dose:

In case a person misses the drug dose, they should take it as soon as they remember. But if it is already time for the next scheduled dose, the missed dose should be skipped, and the regular dosage must be taken. Do not take a double dosage to compensate for the missed drug dose, as it can cause overdose or adverse effects.

Drug Supply, Storage, and Disposal:

Supply

Orphenadrine Citrate ER Tablets, 100 mg (milligrams), is a white, round, convex tablet. It has “G” imprinted on one side and “2011” on the other side.

The drug is supplied in

• Bottles of 100: NDC (National Drug Code) 0115-2011-01.

• Bottles of 500: NDC 0115-2011-02.

Storage

The drug should be stored in its air-airtight container at room temperature of about 15 to 30 degrees Celsius (59 to 86 degrees Fahrenheit). It must be stored away from the children in a dry and moisture-free environment.

Disposal

Expired or unneeded tablets of this drug should be disposed of safely so that nobody can consume them accidentally. However, the medication should not be flushed off in toilets; rather, it should be disposed of through a take-back program by contacting the nearest pharmacist or local recycling or garbage department. In addition, one can follow the FDA’s (Food and Drug Administration) guidelines for safe drug disposal if a person cannot have access to a take-back program.

The medications should be safely stored under the lock and away from children to prevent poisoning from drugs.

For Doctors:

Clinical Pharmacology:

Mechanism of Action

The drug is known to bind and inhibit both N-methyl-D-aspartate (NMDA) receptors and H1 receptors. Orphenadrine can restore the motor disturbances induced by hyperkinesia, a neuroleptic. The stimulating effects of the cholinergic system are increased by the dopamine deficiency in the striatum, which is further counteracted by the anticholinergic effects of the Orphenadrine. This produces a mood-elevating effect and thus relaxes the discomfort and pain caused by skeletal muscle spasms.

Pharmacodynamics

The drug is recommended as an adjunct to physical therapy, rest, and other treatment options for relieving musculoskeletal pain. The drug produces anticholinergic effects, specifically a central effect, and a very weak peripheral effect. The drug also shows local anesthetic and antihistaminic properties. Due to an increase in dopamine, Parkinson's syndrome occurs as a result of an imbalance between dopaminergic and cholinergic neurotransmission in the basal ganglia. Therefore Orphenadrine has the potential to restore this disturbed equilibrium and produce favorable effects on the tremors and rigidity of Parkinson’s syndrome. This causes less effect on bradykinesia.

Pharmacokinetics

Absorption: The drug is completely absorbed via the gastrointestinal tract.

Distribution: Not available (Not fully established in humans).

Metabolism: The biotransformation of the drug mainly occurs in the liver. Pharmacologically active metabolites are N-dimethyl orphenadrine and N-dimethyl orphenadrine.

Elimination: The route of elimination is unknown, but it is expected to be eliminated mainly via urine. About eight percent of the unaltered drug can be recovered in the urine.

Ingredients

Active Ingredients: Orphenadrine citrate.

Inactive Ingredients: Magnesium stearate, lactose monohydrate, ethyl-cellulose, and colloidal anhydrous silica.

Dose Form and Strength

The drug is available as a tablet (extended-release), oral form, and each tablet contains 100 mg of Orphenadrine citrate.

Adverse Effects

• The mild-anticholinergic action of the drug is mainly responsible for the adverse reactions caused by Orphenadrine.

• The adverse effects usually occur due to higher drug doses. The initial symptoms experienced by the person are dry mouth, and as the drug dosage is increased per day, side effects include palpitations, urinary retention, tachycardia, blurred vision, vomiting, nausea, increased ocular tension, dizziness, headache, constipation, agitation, hypersensitivity reactions, drowsiness, gastric irritation, tremors, hallucinations, and rarely dermatoses, and urticaria.

• In fewer cases, mental confusion and aplastic anemia may also occur due to higher drug dosage.

These adverse effects can be treated by reducing the drug dosage of the person and followed by continuous monitoring.

Contraindications

Orphenadrine citrate ER tablets are contraindicated in the following conditions:

• Peptic ulcers.

• Glaucoma.

• Intestinal obstructions.

• Urinary tract blockage.

• Prostatic hypertrophy.

• Myasthenia gravis.

• Drug hypersensitivity.

Drug Interactions: The known drug interactions of Orphenadrine citrate ER tablets include

• Aclidinium.

• Alcohol.

• Amoxapine.

• Anticholinergic medications (Atropine, Scopolamine).

• Antihistamines (Chlorpheniramine, Diphenhydramine, Hydroxyzine).

• Antipsychotics (Haloperidol, Quetiapine, Risperidone).

• Barbiturates (Phenobarbital).

• Benzodiazepines (Clonazepam, Diazepam, Lorazepam).

• Benztropine.

• Brimonidine.

• Botulinum toxin.

• Buprenorphine.

• Buspirone.

• Cannabis.

• Carbamazepine.

• Chloral hydrate.

• Clonidine.

• Dimenhydrinate.

• Domperidone.

• Donepezil.

• Efavirenz.

• Entacapone.

• Eszopiclone.

• Gabapentin.

• Galantamine.

• Glycopyrrolate.

• Glycopyrronium.

• Guanfacine.

• Ipratropium.

• Lamotrigine.

• levetiracetam.

• MAO inhibitors (Maprotiline, Phenelzine, Moclobemide).

• Methadone.

• Metoclopramide.

• Mirabegron.

• Narcotic pain relievers (Codeine, Fentanyl, Morphine).

• Other muscle relaxants (Baclofen, Cyclobenzaprine, Methocarbamol, Tizanidine).

• Phenytoin.

• Potassium chloride.

• Pramipexole.

• Pyridostigmine.

• Rivastigmine.

• Ropinirole.

• Rufinamide.

• St. John's wort.

• Scopolamine.

• Tetrabenazine.

• Thiazide diuretics (Hydrochlorothiazide, Metolazone).

• Tiotropium.

• Topiramate.

• Tramadol.

• Trazodone.

• Tricyclic antidepressants (Amitriptyline, Clomipramine, Desipramine, Nortriptyline).

• Umeclidinium.

• Valerian.

• Valproic acid.

• Zolpidem.

• Zopiclone.