Orphenadrine-to relieve pain and discomfort caused by strains, sprains, and other muscle injuries.

Orphenadrine is used with rest, physical therapy, and other measures to relieve pain and discomfort caused by strains, sprains, and other muscle injuries. Orphenadrine is in a class of medications called skeletal muscle relaxants. It works by changing the way the body senses muscle pain.

Orphenadrine-to relieve pain and discomfort caused by strains, sprains, and other muscle injuries.

Orphenadrine; Disipal; Orphenadine; Orphenadrin; O-Methyldiphenhydramine

Orphamol, Orphipal

Dimethyl({2-[(2-methylphenyl)(phenyl)methoxy]ethyl})amine

Orphenadrine binds and inhibits both histamine H1 receptors and NMDA receptors. The dopamine deficiency in the striatum increases the stimulating effects of the cholinergic system. This stimulation is counteracted by the anticholinergic effect of orphenadrine. It may have a relaxing effect on skeletal muscle spasms and it has a mood elevating effect.

• 2ml (60 mg) every 12 hours as IM/IV injection.
• 150 mg daily in divided doses, maintenance dose is 150-300 mg/day as PO.

Skeletal muscle relaxant, used to treat painful muscle spasm

Palpitation, tachycardia; agitation, drowsiness, dizziness, euphoria, hallucination, headache, mental confusion; pruritus, urticaria; constipation, gastric irritation, nausea, vomiting, xerostomia; urination hesitancy, urinary retention; aplastic anaemia (rare); tremor, weakness; blurred vision, increased intraocular pressure, nystagmus, pupil dilatation; nasal congestion; hypersensitivity.

• Reduced effect with acetylcholinesterase inhibitors e.g. donepezil, galantamine, rivastigmine, tacrine; may reduce effect of centrally-acting acetylcholinesterase inhibitors.
• Additive sedative effects with CNS depressants, alcohol.
• The anticholinergic effect on the GI tract may increase Pramlintide.
• Additive CNS depression may occur with valerian, St John's wort, kava kava, gotu kola.
• Increased risk of anticholinergic adverse effects with TCAs, diphenhydramine, phenothiazines.

Glaucoma, prostatic hypertrophy, GI obstruction, stenosing peptic ulcer, bladder neck obstruction, cardiospasm, myasthenia gravis.

Store at 15-30°C (59-86°F). 

Molecular weight

269.3813

Molecular formula

C18H23NO

CAS number

83-98-7

Precautions

• Elderly
• May impair ability to drive or operate machinery.
• Pregnancy and lactation.
• History of drug abuse or acute alcoholism.
• CHF, coronary insufficiency, cardiac decompensation, tachycardia, or cardiac arrhythmias.