Orphenadrine

Brand Name:Norflex, Sandoz Norgesic, Norgesic Forte

Prescription needed: No

What is this drug used for?

Orphenadrine is used alone or in combination with other pain relievers in the treatment of muscular pain, stiffness and soreness caused by strains, sprains or any other muscular injury. It is also sometimes used in the treatment of trembling associated with Parkinson’s disease.

Orphenadrine is a muscle relaxing drug that works by slowing down the transmission of signals from the central nervous system to the muscles. This reduces muscular stimulation and unwanted muscular contractions.

Is there any reason not to take this drug?

You should not take this drug if you are allergic to orphenadrine.
Tell your doctor if you have or have ever had:
  • glaucoma (especially narrow angle glaucoma or untreated glaucoma)
  • myasthenia gravis
  • problems with stomach ulcers
  • problems with your kidney, liver or prostate
  • difficulty going to the bathroom (e.g. urinary tract blockage ,urinary retention, urinary incontinence)
  • heart rhythm problems
  • other heart problems including heart failure
  • problems with constipation or blockage of intestines
Always disclose your full medical history with the medical team that is taking care of you, in order for them to provide you with the safest and most effective care.

What about possible side effects?

This medication is usually well tolerated but you should be aware of some potential side effects. The following side effects are more common and can be quite bothersome, but unless they are severe, you may continue taking orphenadrine. Contact your doctor or pharmacist to get advice on how to manage these side effects:
  • blurred vision
  • constipation
  • difficulty urinating
  • dizziness
  • drowsiness
  • dry mouth
Other less common side effects include:
  • facial flushing
  • “racing heart” sensation
  • lightheadedness
  • agitation
  • confusion
  • itching or mild rash
  • muscle weakness
  • nasal congestion
  • rash
  • nausea or stomach upset
These side effects are usually related to dose, the use of other medications and other factors (e.g. older age, other medical conditions).  As well, some of these side effects may go away with time. Talk to your doctor or pharmacist about whether you have any risk factors that may make you more sensitive to these side effects.  Contact your doctor if these symptoms continue or become worse

Possible signs of allergic reaction - call your doctor immediately if you experience any of the following while taking orphenadrine:
  • swelling of the face, throat or tongue
  • an itchy skin reaction combined with redness and hives
  • any skin reaction involving a large area of the body
  • severe dizziness or fainting
  • shortness of breath, difficulty breathing or wheezing
  • sensation of choking
  • unusual bleeding/bruising
This is not a complete list of side effects.  If you are concerned about these or other unusual symptoms while taking this medication, ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?


Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as these are the most common interactions and he/she may need to make changes or monitor you more closely:

  • drugs that can cause tiredness, sleepiness, dizziness may increase the chances of having the same side effects - talk to your doctor or pharmacist if you are taking any of the following drugs:
  • opioid pain medications (e.g. codeine, oxycodone, morphine, hydromorphone)
  • opioid cough medications (e.g. hydrocodone, codeine)
  • some antidepressants (e.g. amitriptyline, doxepin, venlafaxine,  paroxetine, trazodone)
  • medications for anxiety and insomnia (e.g. lorazepam, diazepam, oxazepam, temazepam, zopiclone)
  • antipsychotics (e.g. risperidone, haloperidol)
  • other muscle relaxants (e.g. cyclobenzaprine, baclofen)
  • drugs for epilepsy (gabapentin, phenytoin, phenobarbital, carbamazepine, valproic acid)
  • antihistamines (e.g. diphenhydramine, chlorpheniramine, hydroxyzine)
  • alcoholic beverages, including wine, liquors, beer
  • herbal products such as valerian, kava kava, St John’s Wort, gotu kola
  • drugs that  can cause dry mouth, dry eyes, problems urinating or constipation (e.g. amitriptyline, desipramine, imipramine; ask your doctor or pharmacist) - increase your chances of having similar side effects
  • acetylcholinesterase inhibitors (e.g. galantamine, donepezil, rivastigmine) – orphenadrine may reduce the effectiveness of these drugs
This is not a complete list of drug interactions.  Ask your doctor or pharmacist to review your list of medications.

Other information:

Special Instructions: Do not crush or chew the long acting formulations (e.g. Norflex). These tablets are meant to be swallowed whole.

Potential to cause dry mouth can lead to tooth decay – brush teeth daily and visit your dentist on a regular basis.

Children: Not usually prescribed. Talk to your doctor.  

Seniors: Are more sensitive to side effects such as difficulty urinating, drowsiness, dizziness, rare cases of confusion, heart problems. Risks may outweigh benefits. Consult with your doctor beforehand and be aware of potential for side effects.

Pregnant women: Safety not established. Talk to your doctor.

Women who are nursing: This drug passes into breast milk so your infant may be exposed. Not recommended for use in infants so consult with your doctor before taking. 

People who drive or operate machinery: May cause sudden dizziness, drowsiness, blurry vision. Should not do so until they know how this drug affects them personally.

Alcohol: Avoid alcohol when taking orphenadrine due to increased risks of drowsiness and dizziness.

Overdose: A large dose of this medicine could cause pronounced drowsiness and other severe symptoms such as palpitations, fits and even loss of consciousness. If you experience any unusual reactions, or if you suspect an overdose, call 911 or have someone call for you.

Stopping the drug: Your symptoms may return when you stop taking orphenadrine.

If you miss a dose: Take it as soon as you remember, then continue to take the following dose as directed (e.g. if your dosage is 1 tablet twice daily, or every 12 hours, take your missed dose when you remember, then take your next dose about 12 hours later. If your next dose is supposed to be taken while you are asleep, you may choose to take the next dose when you wake up). Do not take a double dose.

Storage conditions: Closed container; cool, dry location away from excess moisture (not in the bathroom) and light; always out of reach of children.

Dietary precautions: None unless prescribed by your doctor