Muscle Relaxant - Side Effects

Side Effects

Muscle relaxants are very powerful drugs which may produce negative effects, including heart failure and paralysis. Patients most commonly report sedation as the main adverse effect of muscle relaxants. Usually, people become less alert when they are under the effects of muscle relaxant drugs. People are normally advised to not drive vehicles or operate heavy machinery while under muscle relaxants' effects.

Cyclobenzaprine produces confusion and lethargy, as well as anticholinergic side effects. When taken in excess or in combination with other substances, it may also be toxic. While the body adjusts to this medication, it is possible for patients to experience dry mouth, fatigue, lightheadedness, constipation or blurred vision. Some serious but unlikely side effects may be experienced, including mental or mood changes, possible confusion and hallucinations, and difficulty urinating. In a very few cases, very serious but rare side effects may be experienced: irregular heartbeat, yellowing of eyes or skin, fainting, abdominal pain including stomachache, nausea or vomiting, lack of appetite, seizures, dark urine, or loss of coordination.

Patients taking carisoprodol for a prolonged time have reported dependence, withdrawal and abuse, although most of these cases were reported by patients who had had a history of addiction. These effects were also reported by patients who took it in combination with other drugs with abuse potential, and in fewer cases, there were reports of carisoprodol-associated abuse when used without other drugs with abuse potential.

Common side effects eventually caused by metaxalone include dizziness, headache, drowsiness, nausea, irritability, nervousness, upset stomach and vomiting. Severe side effects may be experienced when consuming metaxalone, such as severe allergic reactions (rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips, or tongue), chills, fever, and sore throat, may require medical attention. Other severe side effects include unusual or severe tiredness or weakness, as well as yellowing of the skin or the eyes. When baclofen is administered intrathecally, it may cause CNS depression accompanied with cardiovascular collapse and respiratory failure. Tizanidine may lower blood pressure. This effect can be controlled by administering a low dose at the beginning and increasing it gradually.