Unrelenting muscle spasms at the back of the neck can occur after a minor fender-bender. Sometimes, it may be difficult to actually move the entire torso and neck to drive. Certain conditions, such as lower back pain, fibromyalgia, chronic fatigue syndrome, sprains and strains, can all benefit from muscle relaxants.
Carisoprodol
Carisoprodol is often combined with physical therapy, rest and relaxation techniques to relax the muscles and manage the symptoms of sprains, strains and muscle injuries, says MedlinePlus.
Carisoprodol's side effects include dizziness, drowsiness, a headache, a skin rash, vomiting, stomach pain and a fast heart rate. A skin rash, trouble breathing, weakness, fever and a burning sensation in the eye are other side effects of carisoprodol.
Combining carisoprodol with other medications such as other muscle relaxants, sedatives, tranquilizers, sleeping pills or cold, cough and allergy medications can lead to various drug interactions. Drinking alcohol while taking carisoprodol can lead to increased drowsiness.
Orphenadrine
Orphenedrine works to relieve muscular pain as it stops sending pain sensory information to the brain, says the Drugs website. Like carisoprodol, orphenedrine is also used in combination with physical therapy and rest.
Orphenedrine's side effects include a dry mouth or throat, a headache, vomiting, nausea, constipation, weakness and blurry vision. Orphenedrine can also cause dilated pupils, infrequent urination, seizures, confusion, anxiety and a pounding and rapid heart beat. Orphenadrine may need dosage adjustment in people suffering from heart problems or coronary artery disease (major heart blood vessel). This drug should not be used during pregnancy as it can harm the baby. Orphenadrine can be highly addicting, so it should not be used in people who have a history of drug or substance abuse. Alcohol combined with orphenadrine can lead to drowsiness.
Metaxalone
Like ophenhydramine and carisoprodol, metaxolone is also combined with physical therapy and rest to address muscle problems. The Drugs website says that metaxolone's most common side effects include a headache, drowsiness, dizziness, nervousness, irritability, vomiting and stomach problems. Metaxalone can also cause chills, fever, weakness, fatigue and yellowing of the eyes. An allergic reaction to metaxolone includes such symptoms as difficulty breathing, mouth or throat swelling and hives.
Alcohol and metaxalone combined can cause severe drowsiness and dizziness. Benzodiazepine medications such as diazepam, narcotic pain medications like codeine and tricyclic antidepressants like amitriptyline can increased drowsiness. Sodium oxybate combined with metaxolone can increase the length of sleep and make breathing more difficult, says Drugs.com.
