The following information is a summary about Invagesic. It is not intended to replace a doctor's instructions.
What is orphenadrine?
Orphenadrine is a muscle relaxant. It works by blocking nerve impulses (or pain
sensations) that are sent to your brain.
Orphenadrine is used, along with rest and physical therapy, to treat injuries and other
painful muscular conditions.
Although it has not been approved by the FDA for this purpose, orphenadrine has
also been used to treat nighttime leg cramps that have not responded to other medicines.
Orphenadrine may also be used for purposes other than those listed in this medication
guide.
What is the most important information I should know about orphenadrine?
Use caution when driving, operating machinery, or performing other hazardous
activities. Orphenadrine may cause dizziness or drowsiness. If you experience dizziness or
drowsiness, avoid these activities.
Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are
taking orphenadrine.
Do not crush or chew the extended-release tablets. Swallow them whole. They are
specially formulated to release slowly in your body.
Who should not take orphenadrine?
Do not take orphenadrine if you have
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glaucoma,
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an obstruction or an ulcer in your stomach,
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an enlarged prostate or a blockage in your urinary tract
(difficulty urinating), or
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myasthenia gravis.
Before taking orphenadrine, tell your doctor if you have kidney
disease, liver disease, or heart disease. You may need a lower dose or special monitoring during
your therapy.
It is not known whether orphenadrine will harm an unborn baby. Do not take
orphenadrine without first talking to your doctor if you are pregnant.
It is also not known whether orphenadrine passes into breast milk. Do not take
orphenadrine without first talking to your doctor if you are breast-feeding a baby.
Orphenadrine is not approved for use in children.
How should I take orphenadrine?
Take orphenadrine exactly as directed by your doctor. If you do not understand these
directions, ask your pharmacist, nurse, or doctor to explain them to you.
Take each dose with a full glass of water.
Orphenadrine is usually taken two tablets per day; one in the morning and one in the
evening. Follow your doctor's instructions.
Do not crush or chew the extended-release tablets. Swallow them whole. They are
specially formulated to release slowly in your body.
Store orphenadrine at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the missed dose as soon as you remember. However, if it is almost time for your
next dose, skip the missed dose and take only your next regularly scheduled dose. Do
not take a double dose of this medication.
What happens if I overdose?
Seek emergency medical attention.
Symptoms of a orphenadrine overdose include seizures, an irregular heartbeat, low blood
pressure (dizziness, fainting), cold, clammy skin, confusion, and coma. Death can occur in 3 to 5
hours.
What should I avoid while taking orphenadrine?
Use caution when driving, operating machinery, or performing other hazardous
activities. Orphenadrine may cause dizziness or drowsiness. If you experience dizziness or
drowsiness, avoid these activities.
Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are
taking orphenadrine.
Orphenadrine side effects
If you experience any of the following serious side effects, stop taking orphenadrine
and seek emergency medical attention:
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an allergic reaction (difficulty breathing; closing of your throat;
swelling of your lips, tongue, or face; or hives);
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an irregular or a very fast heartbeat; or
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confusion, hallucinations, or abnormal behavior.
Other, less serious side effects may be more likely to occur. Continue
to take orphenadrine and talk to your doctor if you experience
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dry mouth;
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drowsiness or dizziness;
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headache;
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tremor;
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blurred vision or large pupils;
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difficulty urinating;
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dry mouth; or
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nausea, stomach upset, or constipation.
Side effects other than those listed here may also occur. Talk to your
doctor about any side effect that seems unusual or that is especially bothersome.
What other drugs will affect orphenadrine?
Tell your doctor if you are taking amantadine (Symmetrel) before starting orphenadrine
therapy. Orphenadrine and amantadine (Symmetrel) can both cause side effects such as dry
mouth, difficulty urinating, constipation, blurred vision, and others. Together, these side effects
may be more pronounced.
Many drugs can increase the effects of orphenadrine, which can lead to heavy sedation.
Before taking this medication, tell your doctor if you are taking any of the following medicines:
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antihistamines such as brompheniramine (Dimetane, Bromfed,
others), chlorpheniramine (Chlor-Trimeton, Teldrin, others), azatadine (Optimine), clemastine
(Tavist), and many others;
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narcotics (pain killers) such as meperidine (Demerol),
morphine (MS Contin, MSIR, others), propoxyphene (Darvon, Darvocet), hydrocodone (Lorcet,
Vicodin), oxycodone (Percocet, Percodan), fentanyl (Duragesic), and codeine (Fiorinal,
Fioricet, Tylenol #3, others);
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sedatives such as phenobarbital (Solfoton, Luminal),
amobarbital (Amytal), and secobarbital (Seconal);
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phenothiazines such as chlorpromazine (Thorazine),
fluphenazine (Prolixin), mesoridazine (Serentil), perphenazine (Trilafon), prochlorperazine
(Compazine), thioridazine (Mellaril), and trifluoperazine (Stelazine); or
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antidepressants such as doxepin (Sinequan), imipramine
(Tofranil), nortriptyline (Pamelor), fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft),
phenelzine (Nardil), and tranylcypromine (Parnate).
Drugs other than those listed here may also interact with orphenadrine.
Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.
Where can I get more information?
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Your pharmacist has more information about orphenadrine written for health
professionals that you may read.
What does my medication look like?
Orphenadrine is available with a prescription under the brand name Norflex. Other brand
or generic formulations may also be available. Ask your pharmacist any questions you have
about this medication, especially if it is new to you.
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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
