Muscle relaxers are used to treat acute pain due to strains, sprains and other muscular injuries. Muscle relaxers primarily work by either depressing the central nervous system or blocking pain receptors. Avoid alcohol when taking any muscle relaxer as it can increase the sedative effect.
Flexeril is also known by the generic name cyclobenzaprine. Common side effects include dizziness, fatigue, dry mouth, impaired thinking and confusion. Rarer, more serious side effects include seizures and stroke. This medication should not be taken by those with congestive heart failure or an overactive thyroid.
The generic name for Skelaxin is metaxalone. Common side effects are dizziness, nausea and vomiting, drowsiness, headache and nervousness. Skelaxin has very few serious side effects but it should not be used by those with sever kidney disease, liver disease or anemia. Avoid cold or allergy medicines while taking Skelaxin.
Zanaflex (tizanidine) can cause more serious common side effects than other drugs in its class. Aside from the usual dizziness, fatigue, dry mouth and confusion, Zanaflex may also cause low blood pressure and heart rate, urinary tract infection, flulike symptoms and speech disturbances. Serious side effects include severe low blood pressure, high blood pressure and heart rate upon discontinuance, cornea and retinal damage, kidney toxicity and hallucinations. It cannot be taken with the antidepressant Luvox or the antibiotic Cipro.
Although more commonly used for anxiety and sedation, Valium (diazepam) is also prescribed for muscle spasms. Valium also has a long list of possible common side effects but is generally well-tolerated. Possible side effects are tiredness, confusion, depression, slurred speech, vertigo, nausea, blurred vision, rash, excessive drooling and changes in sex drive. Possible serious side effects are dependency, low blood pressure, difficulty breathing, depression, psychosis and jaundice. Valium can cause birth defects and should not be taken during pregnancy.
Norflex (orphenadrine) is useful in relieving pain from leg cramps and other muscle pain. In addition to the typically common side effects for muscle relaxers it may also cause increased heart rate and palpitations, severe itching, weakness, tremors or agitation. The serious side effects associated with use are hallucinations and allergic reactions. It should not be used by those with an enlarged prostate, swallowing difficulties, glaucoma or urination problems.
Soma (carisoprodol) is prescribed for acute musculoskeletal pain. Drowsiness, dizziness and headache are the most common side effects. It is addictive and can cause withdrawal symptoms if stopped abruptly. Soma should be used with caution in epileptic patients and those with kidney and liver disease.