Norflex (Injection)

Orphenadrine is used to help relax specific muscles in your body and reduce stiffness, pain, and discomfort caused by strains, sprains, or other muscle injuries. However, this medicine does not replace rest, exercise or physical therapy, or other treatments that your doctor may suggest for your condition.

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

This medicine is available only with your doctor's prescription.

Your doctor will only prescribe a few doses of this medicine until your condition gets better, and then you will switch to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.

In deciding to use a medicine, you need to consider the risks of taking it compared to the benefits it may provide. This is a choice to be made by you and your doctor. For this medicine, please 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 information below includes only average doses of this medicine. If your dose is different, do not change it unless your doctor instructs 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 the duration of treatment depend on the medical issue you are treating with this medicine.

Pediatric

Appropriate studies have not been conducted on how age affects the use of orphenadrine in children. Safety and effectiveness 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 related to age, which 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. Consider the potential benefits and risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should never be used together, while in other cases, two different medicines may be used together, even if there is a possibility of interaction. In these instances, your doctor may adjust the dose, or take other precautions. It is very important for your healthcare provider to know if you are taking any of the medicines listed below. The following interactions are significant and may not include all possible interactions.

Using this medicine with any of the following medicines is not recommended. Your doctor may choose not to prescribe this medication or may change other medicines you are taking.

• Potassium Citrate

Using this medicine with any of the following medicines is usually not recommended, but may be necessary in certain situations. If both medicines are prescribed, your doctor may adjust the dose or 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 increase the risk of certain side effects, but using both may be necessary for your treatment. If both medicines are prescribed, your doctor may adjust the dose or frequency of one or both medicines.

• Perphenazine

Interactions with Food/Tobacco/Alcohol

Some medicines should not be taken around mealtime or with certain foods due to possible interactions. Using alcohol or tobacco with certain medicines may also lead to interactions. Talk to your healthcare provider about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Having other medical issues may affect how you use this medicine. Be sure to inform your doctor if you have any other medical conditions, 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 needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, 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. Also, your healthcare professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your healthcare 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.