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Brand name:

Flexeril

Pronounced: FLEX-eh-rill
Generic name: Cyclobenzaprine hydrochloride

Why is this drug prescribed?

Flexeril is a muscle relaxant prescribed to relieve muscle spasms resulting from injuries such as sprains, strains, or pulls. Combined with rest and physical therapy, Flexeril provides relief of muscular stiffness and pain.

Most important fact about this drug

Flexeril is not a substitute for the physical therapy, rest, or exercise that your doctor orders for proper healing. Although Flexeril relieves the pain of strains and sprains, it is not useful for other types of pain.

How should you take this medication?

Flexeril may be taken with or without food.

Flexeril should be used only for short periods (no more than 3 weeks). Since the type of injury that Flexeril treats should improve in a few weeks, there is no reason to use it for a longer period.

Flexeril may cause dry mouth. Sucking a hard candy, chewing gum, or melting ice chips in your mouth can provide temporary relief.

--If you miss a dose...

Take it as soon as you remember, if it is within an hour or so of your scheduled time. If you do not remember until later, skip the missed dose and go back to your regular schedule. Do not take 2 doses at once.

--Storage instructions...

Store away from heat, light, and moisture.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Flexeril.

• More common side effects may include:
  Dizziness, drowsiness, dry mouth

• Less common or rare side effects may include:
  Abnormal heartbeats, abnormal sensations, abnormal thoughts or dreams, aggressive behavior, agitation, anxiety, bloated feeling, blurred vision, confusion, constipation, convulsions, decreased appetite, depressed mood, diarrhea, difficulty falling or staying asleep, difficulty speaking, disorientation, double vision, excitement, fainting, fatigue, fluid retention, gas, hallucinations, headache, heartburn, hepatitis, hives, increased heart rate, indigestion, inflammation of the stomach, itching, lack of coordination, liver diseases, loss of sense of taste, low blood pressure, muscle twitching, nausea, nervousness, palpitations, paranoia, rash, ringing in the ears, severe allergic reaction, stomach and intestinal pain, sweating, swelling of the tongue or face, thirst, tingling in hands or feet, tremors, unpleasant taste in the mouth, urinating more or less than usual, vague feeling of bodily discomfort, vertigo, vomiting, weakness, yellow eyes and skin

Problems such as confusion or hallucinations are more likely in older adults.

Why should this drug not be prescribed?

You should not take this drug if you are taking an antidepressant drug known as an MAO inhibitor (such as Nardil or Parnate) or have taken an MAO inhibitor within the last 2 weeks. Also avoid Flexeril if you have ever had an allergic reaction to it, or if your thyroid gland is overactive.

In addition, you should not take Flexeril if you have recently had a heart attack or if you have congestive heart failure, or suffer from irregular heartbeat.

Special warnings about this medication

Flexeril may cause you to become drowsy or less alert; therefore, you should not drive or operate dangerous machinery or participate in any hazardous activity that requires full mental alertness until you know how this drug affects you.

You should use Flexeril with caution if you have ever been unable to urinate or if you have ever had the eye condition called glaucoma.

Possible food and drug interactions when taking this medication

Serious, potentially fatal reactions may occur if you take Flexeril with an antidepressant drug known as an MAO inhibitor (such as Nardil, Parnate) or if it has been less than 2 weeks since you last took an MAO inhibitor. You should closely follow your doctor's advice regarding discontinuation of MAO inhibitors before taking Flexeril.

Avoid alcoholic beverages while taking Flexeril.

If Flexeril is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Flexeril with the following:

Barbiturates such as phenobarbital
Guanethidine and other high blood pressure drugs
Other drugs that slow the central nervous system, such as Halcion and Xanax
Tramadol (Ultram)

Special information if you are pregnant or breastfeeding

The effects of Flexeril during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, inform your doctor immediately. It is not known if Flexeril appears in breast milk. However, cyclobenzaprine is related to tricyclic antidepressants, and some of those drugs do appear in breast milk. If this medication is essential to your health, your doctor may advise you to discontinue breastfeeding your baby until your treatment is finished.

Recommended dosage

ADULTS

CHILDREN

Overdosage

Any medication taken in excess can have serious consequences. If you suspect a Flexeril overdose, seek medical attention immediately.

• Symptoms of Flexeril overdose may include:
  Agitation, coma, confusion, congestive heart failure, convulsions, dilated pupils, disturbed concentration, drowsiness, hallucinations, high or low temperature, increased heartbeats, irregular heart rhythms, muscle stiffness, overactive reflexes, severe low blood pressure, stupor, vomiting

High doses also may cause any of the conditions listed in "What Side Effects May Occur?"