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Overview: Orphenadrine is used short-term to relieve muscle, bone, and joint pain. The medicine may work by changing how your body senses muscle pain. Common side effects include dry mouth, dizziness, and headache. Do not drive or do other activities that require alertness or coordination until you know how orphenadrine affects you.

Uses

What is orphenadrine used for?

Orphenadrine is commonly used for discomfort related to short-term, painful musculoskeletal conditions. These are conditions that affect the muscles, bones, and joints of your body.

Orphenadrine may also be used for other conditions as determined by your healthcare provider.

How does orphenadrine work (mechanism of action)?

Orphenadrine may work by changing how your body senses muscle pain. 

How is orphenadrine supplied (dosage forms)?

Dosage forms and strengths

  • 100 mg extended-release oral tablets

Orphenadrine is also available in injectable forms. 

How should I store orphenadrine?

Oral Tablets. Orphenadrine extended-release tablets should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Injection. Orphenadrine injection is usually given by a healthcare provider in a hospital or clinic. You will not store it at home.

Side Effects

What are the most common side effects of orphenadrine?

The most common side effects of orphenadrine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Dry mouth
  • Increased heart rate
  • Feeling of skipped heartbeats
  • Difficulty peeing
  • Blurred vision
  • Weakness
  • Nausea and vomiting
  • Headache
  • Dizziness (see below)
  • Constipation
  • Drowsiness

There may be other side effects of orphenadrine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of orphenadrine?

While less common, the most serious side effects of orphenadrine are described below, along with what to do if they happen.

Severe Allergic Reactions. Orphenadrine may cause allergic reactions, which can be serious. Stop using orphenadrine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Dizziness. Orphenadrine can make you dizzy. Do not drive or do other activities that require alertness or coordination until you know how orphenadrine affects you.

Risk of Misuse. Misusing orphenadrine can lead to serious side effects like coma or death. Misuse means taking a medicine in a way other than how it was prescribed. Use orphenadrine exactly as prescribed. Tell your healthcare provider if you feel that orphenadrine is not working. Call your healthcare provider right away or go to the nearest emergency room if you have any of the following serious symptoms.

  • Increased energy or excitement
  • Sudden confusion or feeling disoriented
  • Feeling paranoid
  • Suicidal thoughts or actions
  • Seizures
  • Trouble breathing

Warnings & Precautions

Who should not use orphenadrine?

Allergies to Ingredients. People who are allergic to any of the following should not use orphenadrine.

  • Orphenadrine
  • Norflex
  • Any other medicine known as a sulfite (injectable liquid)
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific orphenadrine products they stock.

Glaucoma. Orphenadrine should not be used if you have glaucoma.

Gut Blockage. Orphenadrine should not be used if you have certain types of intestinal obstruction. 

Esophagus or Stomach Problems. Orphenadrine should not be used if you have a condition called pyloric obstruction, a certain type of stomach ulcer called stenosing peptic ulcer, or megaesophagus, which can be a complication of achalasia (trouble swallowing food or liquids). 

Enlarged Prostate. Orphenadrine should not be used if you have prostate hypertrophy. 

Inability to Empty Bladder (Urinary Retention). Orphenadrine should not be used if you have bladder obstruction and have trouble peeing. 

Myasthenia Gravis. Orphenadrine should not be used if you have myasthenia gravis. 

What should I know about orphenadrine before using it?

Do not use orphenadrine unless it has been prescribed to you by a healthcare provider. Use it as prescribed.

Do not share orphenadrine with other people, even if they have the same condition as you. It may harm them.

Keep orphenadrine out of the reach of children.

Orphenadrine is usually used with rest, physical therapy, or other measures to help with discomfort related to painful musculoskeletal conditions.

Orphenadrine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how orphenadrine affects you.

People who are aged 65 years and older can be at greater risk for some side effects from orphenadrine. Talk to your healthcare provider about your risks if you are in this age group.

Orphenadrine is usually only used short term. Your healthcare provider may run certain blood tests if you use this medicine long term.

What should I tell my healthcare provider before using orphenadrine?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if orphenadrine is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Heart problems, including arrhythmias or heart failure
  • Breathing problems, such as asthma

Other Medicines and Supplements. Orphenadrine may interact with other medicines and supplements. Before using orphenadrine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how orphenadrine could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant.

Breastfeeding. It is not known if orphenadrine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. 

Interactions

Does orphenadrine interact with foods or drinks?

There are no known interactions between orphenadrine and foods or drinks.

It is unknown if drinking alcohol will affect orphenadrine. The risk of drowsiness and dizziness may be increased if you drink alcohol while using orphenadrine.

Does orphenadrine interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before using orphenadrine. 

  • An anticholinergic medicine, which includes antihistamines and medicines commonly used for overactive bladder, Parkinson’s disease, or stomach problems
  • Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, or medicines for anxiety

This may not be a complete list of medicines that can interact with orphenadrine. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much orphenadrine?

If you or someone else has used too much orphenadrine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of orphenadrine?

Oral Tablets. If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.

Injection. Orphenadrine injection is usually given by a healthcare provider in a hospital. Your healthcare provider will make sure you are receiving it as scheduled. If you miss an appointment to get your injection, call to make another appointment as soon as possible.