Norflex (Orphenadrine) is NOT a Controlled Drug in Western Australia
Orphenadrine (Norflex) is not classified as a controlled substance in Australia, including Western Australia. It is available as a prescription-only medication (Schedule 4 under the Australian Poisons Standard) but does not carry controlled drug restrictions that apply to substances like opioids or benzodiazepines.
Regulatory Classification
Orphenadrine is classified as a Schedule 4 (S4) medication in Australia, meaning:
- Requires a prescription from a registered medical practitioner
- No special controlled drug prescribing requirements (no duplicate prescriptions, no quantity limits beyond clinical judgment)
- Can be prescribed and dispensed like other standard prescription medications
- Not subject to the same monitoring and reporting requirements as Schedule 8 controlled drugs
Clinical Context
Orphenadrine is a centrally acting skeletal muscle relaxant with anticholinergic properties 1. The medication is indicated as an adjunct to rest and physical therapy for relief of discomfort associated with acute painful musculoskeletal conditions 2.
Key prescribing considerations:
- Mechanism: Does not directly relax skeletal muscles; effects may be related to analgesic and anticholinergic properties 2
- Common formulations: Available as 100mg extended-release tablets and injectable forms 2
- Perioperative guidance: Should be held on the day of surgery due to anticholinergic effects and CNS depression 1
Important Safety Warnings
While not a controlled drug, orphenadrine carries significant safety concerns 2:
- May cause light-headedness, dizziness, or syncope
- Impairs ability to operate machinery or drive vehicles
- Contraindicated in patients with glaucoma, myasthenia gravis, GI obstruction, prostatic hypertrophy, and bladder outlet obstruction 1
- Use with caution in elderly patients and those with cardiac conditions (tachycardia, cardiac decompensation, arrhythmias) 1
- Potentiates anticholinergic effects when combined with other anticholinergic medications 1
Clinical Efficacy Evidence
The combination of orphenadrine with NSAIDs (particularly diclofenac) or paracetamol has demonstrated superior efficacy compared to single agents for musculoskeletal pain 3, 4, 5, though recent evidence suggests the added benefit of orphenadrine may be modest 6.