Skeletal Muscle Relaxants (Systemic)
Side Effects of This Medicine
Along with its needed effects, a medicine may cause some unwanted effects.
Although not all of these side effects may occur, if they do occur they may
need medical attention.
Check with your doctor as soon as possible if any of the following side
Fainting; fast heartbeat; fever; hive-like swellings (large) on
face, eyelids, mouth, lips, and/or tongue; mental
depression; shortness of breath, troubled breathing,
tightness in chest, and/or wheezing; skin rash, hives,
itching, or redness; slow heartbeat (methocarbamol
injection only); stinging or burning of eyes; stuffy nose and red or bloodshot eyes
Blood in urine; bloody or black, tarry
stools; convulsions (seizures) (methocarbamol injection
only); cough or hoarseness; fast or irregular breathing; lower back or side pain; muscle cramps or pain (not present before treatment
or more painful than before treatment); painful or
difficult urination; pain, tenderness, heat, redness,
or swelling over a blood vessel (vein) in arm or leg (methocarbamol injection
only); pinpoint red spots on skin; puffiness or swelling of the eyelids or around the eyes; sores, ulcers, or white spots on lips or in mouth; sore throat and fever with or without chills; swollen
and/or painful glands; unusual bruising or bleeding; unusual tiredness or weakness; vomiting of blood or material that looks like coffee grounds; yellow eyes or skin
Other side effects may occur that usually do
not need medical attention. These side effects may go away during treatment
as your body adjusts to the medicine. However, check with your doctor if any
of the following side effects continue or are bothersome:
Less common or rare
Abdominal or stomach cramps or pain; clumsiness or unsteadiness; confusion; constipation; diarrhea; excitement, nervousness, restlessness, or irritability; flushing or redness of face; headache; heartburn; hiccups; muscle weakness; nausea or vomiting; pain or peeling of skin at place of injection (methocarbamol
only); trembling; trouble
in sleeping; uncontrolled movements of eyes (methocarbamol
Although not all of the
side effects listed above have been reported for all of these medicines, they
have been reported for at least one of them. However, since all of these skeletal
muscle relaxants have similar effects, it is possible that any of the above
side effects may occur with any of these medicines.
In addition to the other side effects listed above, chlorzoxazone may cause
your urine to turn orange or reddish purple. Methocarbamol may cause your
urine to turn black, brown, or green. This effect is harmless and will go
away when you stop taking the medicine. However, if you have any questions
about this, check with your doctor.
Other side effects not listed above may also occur in
some patients. If you notice any other effects, check with your doctor.