Orphenadrine: Uses, Safety and Drug Interactions

Orphenadrine: uses, safety and drug interactions

Overview: Orphenadrine is an English generic medicine name. The information here concerns oral orphenadrine citrate used as a muscle relaxant, particularly modified-release tablets. Orphenadrine hydrochloride products used for Parkinsonism in some countries have a different product context. Injections and combination products also require their own instructions and should not be treated as interchangeable with the tablet described here.

Uses and formulation: The reviewed Australian Norflex information describes relief of painful muscle spasm associated with strains, sprains and related musculoskeletal conditions. The US single-ingredient extended-release tablet label describes adjunctive use with rest and physical therapy. The exact product and reason for treatment should therefore be checked rather than inferred from the generic name alone. Safety of continuous long-term treatment has not been established.

Safety: Orphenadrine has antimuscarinic effects. Dry mouth, blurred vision, constipation, urinary problems, drowsiness and confusion can occur. Glaucoma, urinary outflow obstruction and myasthenia gravis are important contraindications, with additional gastrointestinal restrictions in the US label. Heart rhythm disorders require particular care. Pregnancy and breastfeeding information is limited, so a professional assessment is needed rather than an assumption of safety.

Drug interactions: The Australian product information advises avoiding alcohol and other central nervous system depressants. Other antimuscarinic medicines can add adverse effects such as urinary retention, constipation and confusion. The full list should include sleep medicines, sedating antihistamines and medicines for bladder or stomach spasms. Severe confusion, fainting, seizures, inability to pass urine or suspected overdose require urgent assessment; dose changes should be made by the treating professional.

Sources

• Norflex oral modified-release tablets — Australian product information
• Orphenadrine citrate extended-release tablets — US prescribing information
• WHO ATC/DDD Index: orphenadrine citrate M03BC01
• Metoclopramide oral tablets — Teva US prescribing information
• Donepezil hydrochloride oral tablets — Torrent US prescribing information

This page provides an English summary of the cited sources. Source check: 30 October 2026. This date records a source check, not a clinical review by a doctor or pharmacist. Follow the current leaflet for your product and seek professional advice for personal treatment.