Sounds like 'or-FEN-uh-dreen'

Key points about orphenadrine

  • Orphenadrine is used to treat muscle spasms and pain, eg, back pain and tension headaches.
  • Orphenadrine is also called Norflex.
  • Find out how to take it safely and possible side effects.
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Orphenadrine is used to treat muscle spasms and pain such as back pain and tension headaches. It may be helpful for short-term relief and is usually used together with physiotherapy and exercise. Orphenadrine acts in your central nervous system to produce its muscle relaxant effects. Read more about back painwhat to do if you have back pain and tension headaches. In Aotearoa New Zealand orphenadrine is available as tablets and is only available on prescription from your doctor.

  • Orphenadrine is available as tablets (100mg).
  • The usual dose of orphenadrine is 1 tablet, two times a day. 
  • It's recommended for short-term use.
  • Always take your orphenadrine exactly as your doctor has told you.
  • The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.

  • Timing: Take your orphenadrine doses at the same times each day, in the morning and the evening. Swallow your tablets with a glass of water. You can take orphenadrine with or without food.
  • Missed dose: If you miss a dose and remember within an hour or so of the missed dose, take it right away. But if you don't remember until later, just take the next dose at the right time. Don't take double the dose.

Here are some things to know when you're taking orphenadrine. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Swallow the tablets whole, don't crush or chew them.
  • This medicine may make you drowsy. Be careful when driving or using tools until you know how this medicine affects you.
  • Limit alcohol while you're taking orphendrine. Alcohol can increase the side effect of drowsiness.
  • If you are taking any antihistamines or anti-nausea medicines (to stop feeling like you want to vomit) please check with your healthcare provider before taking orphenadrine.
  • Let your doctor know if you have glaucoma, problems with your prostate, problems with your heart, or acid reflux.
  • Orphenadrine can interact with some medicines, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting orphenadrine and before starting any new products.

Like all medicines, orphenadrine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Constipation
  • This is quite common when you start taking orphenadrine.
  • Ask your doctor to prescribe a laxative, which you'll need to take regularly.
  • Eat a high fibre diet with more fruit, vegetables, brown bread rather than white bread, and bran-based breakfast cereals and drink plenty of water.
  • Tell your doctor if it bothers you or if you have stomach pain.
  • Dry mouth
  • This is quite common when you start taking orphenadrine.
  • Try using sugarless gum or lollies, melt some ice in your mouth or use a saliva substitute.
  • Tell your doctor if a dry mouth bothers you and continues for longer than 2 weeks.
  • Feeling sleepy, confused, dizzy or tired
  • This is common when starting orphenadrine or after increasing the dose.
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Don't drink alcohol.
  • Feeling like you want to pee often
  • Tell your doctor if this bothers you.
  • Nausea (feeling sick) or vomiting (being sick) 
  • Tell your doctor if this bothers you.
  • Fast heart rate, palpitations
  • Tell your doctor.
  • Problems with your eyesight 
  • Tell your doctor.
  • Signs of an allergic reaction such as shortness of breath, trouble breathing, tightness in your chest
    and wheezing and skin rash
  • Tell your doctor immediately or ring Healthline 0800 611 116.
Did you know that you can report a medicine side effect to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.(external link)

The following link has more information on orphenadrine.

Norflex(external link) Medsafe Consumer Information Sheets, NZ


5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019 English(external link), te reo Māori  (external link)


  1. Orphenadrine citrate(external link) New Zealand Formulary
  2. Acute low back pain(external link) BPAC, NZ, 2022
  3. New Zealand acute low back pain guide ACC, 2004

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Credits: Healthify He Puna Waiora editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

Last reviewed: