S4 | Prescription Only

What Schedule Is Isosorbide dinitrate?

Isosorbide dinitrate scheduling and classification across Australia, and international jurisdictions. Also known as Isordil Sublingual.

S4 in Australia Source: PBS, TGA Updated April 2026

Isosorbide dinitrate (Isordil Sublingual) is classified as S4 (Prescription Only Medicine - requires a valid prescription from an authorised prescriber) under the Therapeutic Goods Administration (TGA) in Australia.

Key Takeaways

  • Australia (TGA): S4 - Prescription Only Medicine - requires a valid prescription from an authorised prescriber
  • Risk level: Low (1 points)
  • PBS listed: Subsidised under the Pharmaceutical Benefits Scheme in Australia

Scheduling by Jurisdiction

Jurisdiction Regulatory Body Classification Status
Australia TGA (Therapeutic Goods Administration) S4 PBS listed

What S4 Means for Isosorbide dinitrate

Isosorbide dinitrate is classified as S4 under the TGA Standard for the Uniform Scheduling of Medicines and Poisons (SUSMP). Prescription Only Medicine - requires a valid prescription from an authorised prescriber.

Schedule 4 Prescribing Requirements

  • Prescribing: Requires a valid prescription from a registered medical practitioner, dentist, or authorised prescriber.
  • Dispensing: Must be dispensed by a pharmacist against a valid prescription.
  • Repeats: Repeat prescriptions are permitted as specified by the prescriber.

Claims and Workers Compensation Implications

When Isosorbide dinitrate (S4) appears on a claimant's medication list, the scheduling classification affects how claims professionals should assess and manage the claim.

As a Schedule 4 prescription medicine, claims professionals should verify that Isosorbide dinitrate is being prescribed for the compensable injury and review duration against clinical guidelines.

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Related Resources

Medical Disclaimer: This content is for informational purposes for claims professionals and care workers. It is not medical advice. Always consult a qualified healthcare professional for clinical decisions. Drug information is sourced from TGA, FDA, MHRA, PBS, NICE, and CDC databases and may not reflect the latest updates. AllMeds does not replace clinical judgement.