Orphenadrine

Orphenadrine (sold under many brand names worldwide) is an anticholinergic drug of the ethanolamine antihistamine class; it is closely related to diphenhydramine. It is used to treat muscle pain and to help with motor control in Parkinson's disease, but has largely been superseded by newer drugs. This substance is considered a dirty drug due to its multiple mechanism of action in different pathways. It was discovered and developed in the 1940s. Orphenadrine (sold under many brand names worldwide) is an anticholinergic drug of the ethanolamine antihistamine class; it is closely related to diphenhydramine. It is used to treat muscle pain and to help with motor control in Parkinson's disease, but has largely been superseded by newer drugs. This substance is considered a dirty drug due to its multiple mechanism of action in different pathways. It was discovered and developed in the 1940s. As of 2015, the cost for a typical month of medication in the United States is US$25 to 50. Orphenadrine is used to relieve pain caused by muscle injuries like strains and sprains in combination with rest and physical therapy. A 2004 review found fair evidence that orphenadrine is effective for acute back or neck pain, but found insufficient evidence to establish the relative efficacy of the drug in relation to other drugs in the study. Orphenadrine and other muscle relaxants are sometimes used to treat pain arising from rheumatoid arthritis but there is no evidence they are effective for that purpose. A 2003 Cochrane Review of the use of anticholinergic drugs to improve motor function in Parkinson's disease found that as a class, the drugs are useful for that purpose; it identified one single-site randomised, cross-over study of orphenadrine vs placebo. Orphenadrine and other anticholinergics have largely been superseded by other drugs; they have a use in alleviating motor function symptoms, and appear to help about 20% of people with Parkinson's. Orphenadrine has the side effects of the other common antihistamines in large part. Stimulation is somewhat more common than with other related antihistamines, and is especially common in the elderly. Common side effects include dry mouth, dizziness, drowsiness, upset stomach or vomiting, constipation, urine retention, blurred vision, and headache. Its use in Parkinson's is especially limited by these factors. People with glaucoma, digestive problems such as peptic ulcers or bowel obstruction, or sphincter relaxation disorders, or with enlarged prostate, bladder problems, or myasthenia gravis, should not take this drug.