The P-I-E-N-O Parkinsn's List Drug Database

orphenadrine / Norflex^TM , Flexoject^TM , Myophen^TM

CENTRALLY ACTING MUSCLE RELAXANT:

Description: Orphenadrine is an oral and parenteral, centrally acting muscle relaxant. It is used as adjunct therapy for acute, painful musculoskeletal conditions and in the management of quinine-resistant leg cramps.

Orphenadrine's mechanism of action has not been determined, but it may be secondary to its analgesic properties. This drug was approved by the FDA in 1959.

Contraindications: Glaucoma, peptic obstruction and disease, prostatic hypertrophy, GU obstruction, cardiospasm, myasthenia gravis, cardiac disease, sulfite sensitivity.

Drug Interactions:

Amantadine: Additive anticholinergic effects.

Haloperidol: Worsening of schizophrenic symptoms and possible development of tardive dyskinesia.

Phenothiazines: Decreased therapeutic effects of phenothiazines.

Adverse Reactions: Xerostomia, sinus tachycardia, palpitations, syncope, weakness, headache, dizziness, lightheadedness, confusion, nausea/vomiting, constipation, urinary hesitancy and retention, blurred vision, pupil dilation, aplastic anemia (rare), anaphylactic reaction (rare).

Dosage: 100 mg PO twice daily, morning and evening. Or, 60 mg IV or IM; may be repeated every 12 hours.

Patients with renal impairment: No dosage adjustment needed.

Parkinsn's Archive Treasures Page

John Cottingham is the webmaster of this site.