Orphenadrine (Injection)

Orphenadrine is used to help relax specific muscles in your body and relieve the stiffness, pain, and discomfort caused by strains, sprains, or other injuries to your muscles. However, this medicine does not replace rest, exercise or physical therapy, or other treatments your doctor may recommend for your medical issue.

Orphenadrine works in the central nervous system (CNS) to create its muscle relaxant effects.

This medicine is available only with a prescription from your doctor.

Your doctor will provide you with only a few doses of this medicine until your condition gets better. After that, you will be moved to an oral medicine that works the same way. If you have any questions about this, speak with your doctor.

In deciding to use a medicine, you and your doctor must weigh the risks of taking the medicine against the benefits it may provide. For this medicine, consider the following:

Allergies

The dose of this medicine can vary for different patients. Follow your doctor's instructions or the directions on the label. The following information includes only average doses of this medicine. If your dose is different, do not change it unless your doctor advises you to do so.

The amount of medicine you take depends on its strength. The number of doses you take each day, the time between doses, and how long you take the medicine depends on the medical issue you are treating.

Pediatric

Appropriate studies have not been performed to determine how age affects the use of orphenadrine in children. Safety and efficacy have not been established.

Geriatric

There is no information available on how age affects the use of orphenadrine in older adults. However, elderly patients are more likely to have heart, liver, or kidney issues that may require caution when using orphenadrine.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication while breastfeeding. Weigh the potential benefits against the risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should not be used together. In other cases, two different medicines may be used together even if an interaction might happen. If you are receiving this medicine, it is very important that your healthcare provider knows if you are taking any of the medicines listed below. The following interactions are highlighted based on their potential importance and are not necessarily complete.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or may change some of the other medicines you take.

• Potassium Citrate

Using this medicine with any of the following medicines is usually not recommended, but may be necessary in some situations. If both medicines are prescribed together, your doctor may adjust the dose or the frequency of one or both medicines.

• Alfentanil
• Alprazolam
• Amantadine
• Amifampridine
• Benzhydrocodone
• Bromazepam
• Buprenorphine
• Butorphanol
• Calcium Oxybate
• Cannabidiol
• Cannabis
• Cetirizine
• Clobazam
• Clonazepam
• Clozapine
• Codeine
• Daridorexant
• Dexmedetomidine
• Dihydrocodeine
• Donepezil
• Doxylamine
• Esketamine
• Fentanyl
• Flibanserin
• Gabapentin
• Gabapentin Enacarbil
• Glucagon
• Glycopyrrolate
• Glycopyrronium Tosylate
• Hydrocodone
• Hydromorphone
• Ketamine
• Lacosamide
• Lemborexant
• Levocetirizine
• Levorphanol
• Lofexidine
• Loxapine
• Magnesium Oxybate
• Meperidine
• Methacholine
• Methadone
• Metoclopramide
• Midazolam
• Morphine
• Morphine Sulfate Liposome
• Nalbuphine
• Olanzapine
• Oxycodone
• Oxymorphone
• Pentazocine
• Phenobarbital
• Potassium Oxybate
• Pregabalin
• Primidone
• Quetiapine
• Remifentanil
• Remimazolam
• Revefenacin
• Ropeginterferon Alfa-2b-njft
• Scopolamine
• Secretin Human
• Sodium Oxybate
• Sufentanil
• Tapentadol
• Tiotropium
• Topiramate
• Tramadol
• Trazodone
• Zolpidem
• Zuranolone

Using this medicine with any of the following medicines may lead to a higher risk of certain side effects, but using both medicines may be necessary for your treatment. If both medicines are prescribed together, your doctor may adjust the dose or frequency of one or both medicines.

• Perphenazine

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be taken around the time of eating food or certain types of food because interactions may occur. Drinking alcohol or using tobacco with certain medicines may also cause interactions. Discuss with your healthcare provider about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Other medical issues may affect how this medicine works. Make sure to inform your doctor if you have any other medical problems, especially:

• Enlarged esophagus or
• Enlarged prostate or
• Glaucoma or
• Intestinal blockage or
• Myasthenia gravis or
• Stomach ulcer or
• Urinary tract blockage—Orphenadrine should not be used in patients with these conditions.

• Heart problems (e.g., fast or irregular heartbeats, heart failure)—Use with caution. Orphenadrine may worsen these conditions.

Along with its necessary effects, this medicine may cause some unwanted effects. Not all of these side effects may occur, but if they do, they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

Rare

• Cough
• Difficulty swallowing
• Dizziness
• Fast heartbeat
• Hives
• Itching
• Puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• Shortness of breath
• Skin rash
• Tightness in chest
• Unusual tiredness or weakness
• Wheezing

Incidence not known

• Abdominal or stomach pain
• Diarrhea
• Fast, pounding, or irregular heartbeat or pulse
• Fever
• Glaucoma
• Joint or muscle pain
• Nausea
• Numbness or tingling of face, hands, or feet
• Redness and soreness of eyes
• Shortness of breath
• Sores in mouth
• Swelling of feet or lower legs
• Vomiting

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

Symptoms of Overdose

• Blurred vision
• Confusion, delirium, or hallucinations
• Constipation
• Difficult urination
• Drowsiness
• Dry eyes, mouth, nose, or throat
• Eye pain
• Flushing or redness of face
• Troubled breathing

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Additionally, your health care professional may be able to tell you 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

• Anxiety
• Deep or fast breathing with dizziness
• Headache
• Irritability
• Itching skin
• Mental confusion
• Nervousness
• Numbness of feet, hands, and around mouth
• Restlessness
• Trembling or shaking of hands or feet, shakiness in legs, arms, hands, or feet
• Unusually large pupils of eyes
• Weakness

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

In the U.S.

• Antiflex
• Mio-Rel
• Norflex
• Orfro
• Orphenate

Available Dosage Forms:

• Solution

Therapeutic Class: Skeletal Muscle Relaxant, Centrally Acting

Pharmacologic Class: Antimuscarinic

A nurse or other trained health professional will give you this medicine. This medicine is given through a needle placed in one of your veins or into your muscle.