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Generic Name: orphenadrine (or FEN a drin)
Brand Name: Norflex

What is Norflex (orphenadrine)?

Orphenadrine is a muscle relaxer.

Orphenadrine is used together with rest and physical therapy to treat skeletal muscle conditions such as pain or injury.

Orphenadrine may also be used for purposes not listed in this medication guide.

What is the most important information I should know about Norflex (orphenadrine)?

You should not take this medicine if you have urination problems, an enlarged prostate, glaucoma, a stomach ulcer or blockage in your digestive tract, trouble swallowing, or myasthenia gravis.

What should I discuss with my healthcare provider before taking Norflex (orphenadrine)?

You should not use orphenadrine if you are allergic to it, or if you have:

  • urination problems;

  • an enlarged prostate;

  • glaucoma;

  • a stomach ulcer;

  • a blockage in your stomach or intestines;

  • trouble swallowing; or

  • myasthenia gravis.

To make sure orphenadrine is safe for you, tell your doctor if you have:

  • heart disease;

  • a heart rhythm disorder;

  • coronary artery disease; or

  • if you also use a narcotic (opioid) medication.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether orphenadrine passes into breast milk or if it could affect the nursing baby. Tell your doctor if you are breast-feeding.

Orphenadrine is not approved for use by anyone younger than 18 years old.

How should I take Norflex (orphenadrine)?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Orphenadrine may be habit-forming. Never share orphenadrine with another person, especially someone with a history of drug abuse or addiction. Keep the medication in a place where others cannot get to it. Selling or giving away this medicine is against the law.

Orphenadrine is usually taken 2 times per day, once in the morning and once in the evening. Follow your doctor's dosing instructions.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

Orphenadrine is only part of a complete program of treatment that may also include rest, physical therapy, or other pain relief measures.

Store orphenadrine at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

Keep track of the amount of medicine used from each new bottle. Orphenadrine is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Norflex (orphenadrine)?

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Do not drink alcohol. Dangerous side effects or death can occur.

Norflex (orphenadrine) side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using orphenadrine and call your doctor at once if you have:

  • a light-headed feeling, like you might pass out;

  • painful or difficult urination;

  • little or no urination;

  • confusion, anxiety, agitation, tremors, hallucinations; or

  • pounding heartbeats or fluttering in your chest.

Common side effects may include:

  • dizziness, drowsiness, weakness;

  • nausea, vomiting;

  • dry mouth; or

  • constipation.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Norflex (orphenadrine)?

Taking orphenadrine with other drugs that make you sleepy or slow your breathing can cause dangerous side effects or death. Ask your doctor before taking a sleeping pill, narcotic pain medicine, prescription cough medicine, a muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with orphenadrine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

  • Your pharmacist can provide more information about orphenadrine.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 5.01.

Date modified: May 03, 2017
Last reviewed: March 10, 2017

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