Therapeutic Goods (Serious Scarcity and Substitutable Medicine) (Simvastatin) Instrument 2025

The instrument introduces and ties together a small set of regulatory concepts: serious scarcity, scarce medicine, substitutable medicine, dose unit equivalence, specific permitted circumstances, and general permitted circumstances. Each concept has a defined operational role.

Serious scarcity is declared by the instrument for the identified product under section 30EK of the Therapeutic Goods Act 1989. The legal effect is to trigger substitution powers in relation to the scarce medicine as set out in the instrument (s 5). The scarce medicine in this instrument is explicitly identified in Schedule 1 Column 2 , ZIMSTAT simvastatin 5 mg tablet blister pack, registration number 95672.

Substitutable medicine is a legal category that, for the item in Schedule 1, is defined as a registered medicine that contains 10 mg simvastatin as the only active ingredient and is manufactured in the dosage form of a tablet (Schedule 1 Column 3). The instrument therefore ties substitution permission to a narrowly described product class: registered status, single active ingredient, specific strength and tablet form.

Dose unit equivalence operationalises how a pharmacy-level substitution maps dosage units across strengths. For the item in Schedule 1 the instrument specifies that half a tablet of the 10 mg substitutable medicine equals one tablet of the 5 mg scarce medicine (Schedule 1 Column 4). The instrument thus contemplates tablet splitting as the mechanism to achieve dose equivalence.

Substitution is authorised only where both specific and general permitted circumstances are satisfied (s 6). The specific permitted circumstances in Schedule 1 Column 5 require the pharmacist to advise the patient, or a person acting for the patient, of three discrete matters: the number of dose units of the substitutable medicine to take based on the dose equivalence, suitable instructions for cutting a tablet of the substitutable medicine, and the differences between the scarce and substitutable medicine (Schedule 1 Column 5(a)-(c)). The Schedule therefore converts clinical and practical duties into legal preconditions to substitution.

The general permitted circumstances listed in Schedule 2 set eight conditions that must all be met. They cover documentary evidence of a valid prescription (item 1), lack of pharmacist access to the scarce medicine (item 2), absence of a prescriber prohibition on substitution (item 3), pharmacist professional judgement on patient suitability (item 4), ensuring equivalent dosage regimen and duration (item 5), obtaining patient consent (item 6), contemporaneous recordkeeping of the substitution (item 7), and an established procedure to notify the prescriber at or as soon as practicable after dispensing (item 8). Those conditions distribute decision rights among the prescriber, pharmacist and patient, and allocate operational tasks to the pharmacist.

Definitions anchor the instrument in existing legislative language where relevant. The instrument imports several terms from subsection 3(1) of the Therapeutic Goods Act 1989 (s 4 note). It also defines prescriber as someone authorised under a State or Territory law to prescribe medicine and who prescribed the scarce medicine (s 4). The instrument references the TGO 101 order for the definition of tablet, thereby connecting to a pharmaceutical standards instrument (s 4 note).

Temporal scope is explicit: the instrument commences entirely on 5 December 2025, remains in force until 31 May 2026 and is repealed at the start of 1 June 2026 unless earlier repealed (s 2; ss 7-8). The instrument therefore provides a time-limited, product-specific exception to normal dispensing rules that would otherwise apply under other Commonwealth, State and Territory pharmaceutical controls.

Structurally, the instrument delegates substantive judgement to pharmacists on patient suitability and retains a prescriber right to prevent substitution by marking the prescription accordingly. It centralises certain procedural obligations,advice, cutting instructions, recording and notification,on the pharmacist. The substitutable product requirement being limited to a registered 10 mg tablet containing simvastatin as the only active ingredient narrows the set of eligible products to those appearing on the Register in that form.

The instrument directly affects several discrete groups, with concrete shifts in legal permissions and operational responsibilities.

Pharmacists are the primary decision-makers authorised to dispense the substitutable medicine in substitution for the scarce medicine, but only where the specific and general permitted circumstances exist (s 6). That authorisation confers both a permission and a set of duties. Pharmacists must exercise professional judgement that the patient is suitable (Schedule 2 item 4), advise the patient or their representative of specified information (Schedule 1 Column 5), obtain consent (Schedule 2 item 6), make a record at the time of dispensing (Schedule 2 item 7), and have an established procedure to notify the prescriber (Schedule 2 item 8). The pharmacist also must be in a situation of lacking access to the scarce medicine (Schedule 2 item 2) to rely on the substitution pathway.

Patients prescribed the scarce medicine are the intended beneficiaries of the substitution permission. Where the general and specific circumstances are met, patients may receive a 10 mg tablet split to provide the equivalent 5 mg dose. The instrument explicitly requires patient consent to substitution (Schedule 2 item 6), and requires pharmacists to advise patients about dosing, cutting and differences (Schedule 1 Column 5). Patients therefore gain an option to receive a split higher-strength tablet when the scarce product is unavailable, subject to their consent and the pharmacist’s professional judgement.

Prescribers appear as both rights holders and information recipients. The instrument defines prescriber as a person authorised under State or Territory law who prescribed the scarce medicine (s 4). A prescriber retains the right to prevent substitution by indicating on the prescription that substitution is not permitted, in which case the general permitted circumstance in Schedule 2 item 3 will not be satisfied and substitution cannot occur. Prescribers are also to be notified at the time of, or as soon as practicable after, dispensing if substitution occurs (Schedule 2 item 8).

Manufacturers and sponsors of registered medicines are affected by the market shift the instrument enables. The substitutable medicine must be a registered 10 mg simvastatin tablet (Schedule 1 Column 3). If pharmacists substitute the 10 mg product for the scarce 5 mg product, demand shifts from the scarce product’s supply chain to suppliers of 10 mg tablets, potentially altering sales volumes, inventory turnover and distribution flows.

Wholesalers and pharmacies’ supply chain management are implicated. Pharmacists may only substitute when they "do not have access to the scarce medicine" (Schedule 2 item 2), which links substitution authorisation to availability at the dispensing site. This creates incentives for inventory disclosure and procurement choices. Entities responsible for procurement and inventory in pharmacy businesses must implement procedures to document lack of access and manage increased demand for the substitutable product.

Regulators and payers are affected in operational and fiscal ways. The instrument is a Commonwealth legislative instrument made under the Therapeutic Goods Act 1989 (s 3). While the instrument does not mention pharmaceutical benefits scheme (PBS) arrangements or subsidy implications, substitution that changes strength and pack size may interact with PBS dispensing rules, patient co-payments and claims processing systems. State and Territory regulators that govern prescriber authorisation and pharmacist practice will remain relevant, because the instrument defines prescriber in State/Territory-authority terms and places professional judgement and patient suitability duties on pharmacists (s 4; Schedule 2 item 4).

Finally, healthcare providers, nursing homes and carers are indirectly affected because the instrument authorises a different form of medicine (a split higher-strength tablet) which may require changes in administration practice, documentation and patient instruction. The instrument requires pharmacists to provide cutting instructions and advice about differences between products, educational interactions that can affect those who assist patients with medication administration.

The instrument establishes discrete rights and duties that allocate decision-making and procedural responsibilities primarily to pharmacists, with defined roles for prescribers and patients.

Rights:

• Pharmacists are expressly permitted to dispense the substitutable medicine in substitution for the scarce medicine under the instrument, but only if both the specific and general permitted circumstances exist (s 6). That permission is a conditional delegation of dispensing authority for the specified product pairing.
• Prescribers retain the right to prevent substitution by indicating on the prescription that substitution is not permitted; such an indication means Schedule 2 item 3 is not met and substitution is therefore not authorised (Schedule 2 item 3).
• Patients retain the right to consent or withhold consent to substitution; Schedule 2 item 6 requires patient consent as a general permitted circumstance.

Duties placed on pharmacists:

• Verify evidence of a valid prescription for the scarce medicine, unless otherwise permitted by law (Schedule 2 item 1). The instrument therefore requires documentary or otherwise acceptable proof that the substitution relates to a genuine prescription for the scarce product.
• Ensure the pharmacist does not have access to the scarce medicine (Schedule 2 item 2) before substituting. The instrument conditions substitution on lack of access.
• Exercise professional judgement in determining that the patient is suitable to receive the substitutable medicine (Schedule 2 item 4). This is a substantive clinical and professional obligation.
• Ensure the amount of substitutable medicine dispensed results in an equivalent dosage regimen and duration to that prescribed for the scarce medicine (Schedule 2 item 5). The instrument requires attention to regimen equivalence, not merely per-dose unit equivalence.
• Obtain the patient’s or a person acting for the patient’s consent to receive the substitutable medicine (Schedule 2 item 6).
• Make a record of dispensing the substitutable medicine in substitution of the scarce medicine at the time of dispensing (Schedule 2 item 7). This contemporaneous recordkeeping duty creates an audit trail.
• Maintain and use an established procedure to notify the prescriber of the substitution at the time of, or as soon as practical after, dispensing (Schedule 2 item 8). The timing language leaves some operational discretion but imposes an obligation to notify promptly.
• Provide specified advice to the patient or person acting for the patient: the number of dose units required based on the dose unit equivalence in Schedule 1 Column 4, suitable instructions for cutting a tablet, and the differences between the scarce and substitutable medicines (Schedule 1 Column 5(a)-(c)).

Duties associated with product specification:

• Confirm that the substitutable product meets the instrument’s definition: a registered medicine that contains 10 mg simvastatin as the only active ingredient and is in tablet form (Schedule 1 Column 3). The pharmacist must ensure the product is on the Register and matches the descriptive criteria.

Constraints and conditionality:

• Substitution is only permitted where both the specific permitted circumstances (Schedule 1 Column 5) and the general permitted circumstances (Schedule 2 items 1-8) exist. The instrument repeatedly emphasises the conjunctive requirement: both sets of conditions must be satisfied for substitution to be authorised (s 6 note; s 6).

Absences to note:

• The instrument does not prescribe a specific format for the required record of substitution, nor does it specify the precise content or timing of prescriber notification beyond "at the time of, or as soon as practical after, dispensing" (Schedule 2 item 8).
• The instrument does not itself create a prescriptive clinical protocol for tablet splitting beyond requiring "suitable instructions for cutting a tablet" (Schedule 1 Column 5(b)), nor does it mandate specific training or equipment for pharmacists regarding splitting tablets.

Operational implications of duties:

• The requirement to calculate and advise on the number of dose units, instruct on cutting, and ensure equivalent regimen and duration imposes workload and clinical decision-making responsibilities on pharmacists at the point of care.
• The contemporaneous record and notification requirements create an administrative compliance burden that pharmacy workflows and software systems will need to accommodate.
• The prescriber’s ability to prohibit substitution preserves clinical control but requires prescribers to act proactively on prescriptions to assert that restriction.

The instrument itself contains no express penalty provisions and does not specify enforcement mechanisms within its text. It is made under section 30EK of the Therapeutic Goods Act 1989 (s 3), and therefore any enforcement or contravention consequences would be determined by the Therapeutic Goods Act and any relevant subordinate regulatory frameworks, professional regulatory regimes, and State and Territory law. The instrument does create mandatory duties for pharmacists as conditions of lawful substitution; failure to comply with those duties could therefore have consequences under the broader regulatory and professional regimes that govern medicines and pharmacy practice, but the instrument does not enumerate those consequences.

What the instrument requires, and what falls to external regimes, can be identified from its structure. The instrument authorises substitution only where the general and specific permitted circumstances exist (s 6). If a pharmacist substituted without satisfying those requirements, the act of substitution would not be authorised by the instrument. The legal consequences of unauthorised substitution would then depend on the enforcement provisions of the Therapeutic Goods Act 1989, the registration conditions on the medicines in question, pharmacy practice legislation, professional conduct rules, and any civil liability regimes. The instrument does not specify whether a breach would amount to an offence under the Act, nor does it prescribe administrative sanctions, monetary penalties, or regulatory directions for non-compliance; those matters are governed by the primary Act and other relevant instruments and statutes.

Practically, enforcement paths to consider that are not contained in the instrument but flow from the regulatory architecture that the instrument sits within include:

• Commonwealth regulatory enforcement under the Therapeutic Goods Act 1989 concerning the use and distribution of therapeutic goods, which may include directions, suspensions, or other regulatory actions if related provisions are breached.
• Professional disciplinary mechanisms under State and Territory pharmacy boards or registration authorities for breaches of professional standards, clinical misadvice, inadequate recordkeeping, or failure to obtain consent.
• Civil liability claims arising from harm caused by incorrect dosing or inadequate instructions, where duty of care principles and negligence law apply. The instrument does not immunise pharmacists against civil liability; it prescribes conditions for lawful substitution, but does not state that adhering to the instrument shields pharmacists from other legal exposure.
• Administrative or contractual consequences linked to payer systems such as the PBS if substitution affects subsidy eligibility, dispensing claims, or compliance with PBS documentation requirements. The instrument is silent on PBS interactions.

Implementation and enforcement uncertainty is therefore present. The instrument’s silence on penalties and enforcement mechanics shifts the question of consequences to existing statutes, professional codes and contractual obligations. Entities implementing substitution should therefore assess:

• relevant offence and enforcement provisions in the Therapeutic Goods Act 1989 and subordinate instruments;
• State and Territory pharmacy practice legislation and the obligations under professional registration and code-of-conduct frameworks;
• civil liability risks under general law; and
• requirements of payers and schemes (for example, PBS) that might affect reimbursement or claims processes.

The instrument’s recordkeeping and notification requirements (Schedule 2 items 7 and 8) create discrete compliance obligations that will serve as evidentiary material in any subsequent enforcement or disciplinary process. Compliance systems that capture contemporaneous records and prescriber notifications will therefore materially reduce enforcement risk, but the instrument itself does not set out enforcement pathways or penalties.

The instrument operates as a subordinate legislative instrument under the Therapeutic Goods Act 1989 (s 3), and its legal effects are therefore situated within Commonwealth therapeutic goods law. It also interfaces with State and Territory regulatory regimes and standards instruments referenced in the text. Key interaction points are these.

Therapeutic Goods Act 1989

• The instrument is expressly made under s 30EK of the Therapeutic Goods Act 1989 (s 3). The Act contains the broader regulatory framework for inclusion of goods on the Register, offences, compliance powers and other regulatory mechanisms. The instrument does not restate those Act provisions; it creates a temporary substitution regime that must be read alongside the Act. For legal consequences of non-compliance, one needs to consult the Act and related subordinate instruments.

State and Territory prescribing and pharmacy law

• The instrument defines prescriber as a person authorised under a law of a State or Territory to prescribe medicine (s 4). That definition connects the Commonwealth instrument to State and Territory authorisations and professional registration. Pharmacists’ exercise of professional judgement and duties to patients are regulated by State and Territory pharmacy practice laws and boards. The instrument requires the pharmacist to be satisfied that the prescriber has not prohibited substitution by marking the prescription (Schedule 2 item 3), which interacts with how prescriptions are issued, recorded and interpreted under State and Territory regimes.

Standards for pharmaceutical form

• The instrument uses the term tablet and notes that that expression has the meaning in the Therapeutic Goods (Standards for Tablets, Capsules and Pills) (TGO 101) Order 2019 (s 4 note). That links the instrument’s product-definition obligations to an existing standards instrument which sets out, inter alia, requirements for tablet form, scoring and possibly labelling that are relevant to tablet splitting and suitability for division. The compliance assessment for whether a substitutable tablet is suitable for splitting may therefore involve reference to TGO 101 standards.

Register and product registration

• The substitutable medicine must be a registered medicine as defined by inclusion in the Register for goods known as registered goods, and the scarce medicine is identified by registration number (s 4 definitions; Schedule 1 Column 2 & 3). The Register and the conditions attaching to registration under the Act remain relevant for questions of product identity, permitted uses, labelling and sponsor obligations.

Payer and reimbursement regimes

• The instrument is silent on the Pharmaceutical Benefits Scheme and other reimbursement arrangements. Substituting a 10 mg tablet for a prescribed 5 mg blister pack may alter pack size, PBS item codes and dispensing entitlement. Interactions with PBS rules, rebate eligibility, and software systems are therefore a practical legal interface, but the instrument does not expressly address them. Entities should check the PBS rules and advice from Services Australia when implementing substitution for patients in the PBS.

Consumer protection and product liability

• The instrument requires pharmacists to advise patients of differences between products and provide cutting instructions (Schedule 1 Column 5). Those duties touch consumer protection regimes and civil liability law in the event of harm arising from incorrect splitting or dosing. The instrument does not displace duties under general law relating to negligence, product liability, or consumer guarantees.

Clinical governance and professional standards

• The instrument’s requirement that the pharmacist exercise professional judgement as to suitability (Schedule 2 item 4) interacts with professional codes of conduct and standards issued by pharmacy boards or peak professional bodies. An assessment of what counts as adequate professional judgement must be informed by those standards, and potential disciplinary consequences for inadequate judgement are governed by State and Territory professional regulation.

Pharmaceutical manufacturing and labelling law

• Because the substitutable product must contain only simvastatin as the active ingredient and be in tablet form (Schedule 1 Column 3), manufacturing and labelling requirements that attach to registered medicines under the Act remain applicable. The instrument does not relax manufacturing or labelling obligations.

Practical interoperability issues

• The instrument’s requirement to make a contemporaneous record (Schedule 2 item 7) and to notify the prescriber at or as soon as practicable after dispensing (Schedule 2 item 8) will interact with dispensing software, recordkeeping obligations under State/Territory law and Commonwealth claims systems. Pharmacies will need to ensure that administrative systems can capture substitution events in a compliant and auditable way.

In short, the instrument is a time-limited, product-specific legal authorisation that sits inside the broader therapeutic goods and health professional regulatory architecture. Compliance requires reading the instrument together with the Therapeutic Goods Act 1989, TGO 101 where relevant, State and Territory prescribing and pharmacy regulation, payer rules such as the PBS, and general civil and consumer law obligations.

This instrument records only its original creation and limited temporal parameters; the text itself contains no record of prior amendments. The instrument’s commencement provision specifies that the whole instrument commences on 5 December 2025 (s 2 commencement table). The instrument also specifies its duration, remaining in force until 31 May 2026 (s 7), and that, unless earlier repealed, it is repealed at the start of 1 June 2026 (s 8). The note beneath the commencement table states that the table relates only to the provisions of the instrument as originally made and will not be amended to deal with later amendments of the instrument.

Concretely, the instrument as presented establishes a limited-term, single-item substitution regime: Schedule 1 contains one item (item 1) listing ZIMSTAT simvastatin 5 mg as the scarce medicine and a defined substitutable product class; Schedule 2 lists the general permitted circumstances. There is no other historical amendment recorded in the instrument text.

For users tracking changes or future amendments, the instrument’s own note that the commencement table pertains only to the instrument as originally made signals that any subsequent amendment history will be recorded separately, in the Federal Register of Legislation or in consolidated versions that show changes. Practitioners should consult the Federal Register of Legislation for any post-enactment amendment instruments or replacement instruments that modify the declared scarcity, the substitutable medicine specification, the permitted circumstances, or the instrument’s duration.

Because the instrument is explicitly time-limited and scheduled for repeal at a stated date, its amendment possibilities are operationally constrained. Any amendment extending the period of operation, changing the eligible substitutable medicine, adding items, or altering permitted circumstances would need to be effected by a new or amending instrument made under the same legislative authority, and those amendments would themselves follow the usual legislative instrument registration and commencement requirements.

In sum, the instrument’s amendment history as contained in the text is nil beyond its original making and the stated commencement and repeal dates. Users should monitor the Federal Register of Legislation for any subsequent instruments that amend, replace, or extend the measures embodied here.

The instrument itself contains no references to litigation, and its text does not record any judicial decisions, disputes, appeals or precedent arising from its operation. As a piece of subordinate legislation that declares a scarcity and authorises limited substitution for a specific product, litigation arising from the instrument would necessarily be external to the instrument and would be captured in case law under the Therapeutic Goods Act, professional disciplinary proceedings, or civil actions arising from clinical outcomes. None of those proceedings is referenced or included in the instrument.

Given that the instrument is time-limited and narrowly focused on a single product substitution, potential legal disputes could arise in contexts such as:

• claims that the substitutable medicine was not a registered medicine as defined by the Act or did not meet the instrument’s product specification (Schedule 1 Column 3);
• disputes over whether the general and specific permitted circumstances were satisfied at the time of substitution, for example whether the pharmacist truly lacked access to the scarce medicine, whether the prescriber had validly indicated "no substitution," or whether the pharmacist properly exercised professional judgement on patient suitability (Schedule 2 items 2-4);
• civil claims alleging harm due to inadequate cutting instructions, incorrect dosing from tablet splitting, or misleading advice regarding product differences (Schedule 1 Column 5);
• administrative or disciplinary proceedings under State or Territory pharmacy boards for alleged breaches of professional standards connected with substitution; and
• disputes about reimbursement or claims under the Pharmaceutical Benefits Scheme where substitution might alter pack sizes or PBS item codes.

The instrument’s contemporaneous recordkeeping and prescriber notification requirements (Schedule 2 items 7-8) are likely to be central evidentiary elements in any post-dispensation dispute. The absence of express immunity clauses in the instrument means that adherence to the instrument will not, on its face, preclude civil liability or regulatory sanctions where other laws or professional standards are contravened, but the instrument provides an express lawful pathway for substitution which will be relevant in legal analysis.

For practitioners seeking litigation or case law guidance, there is no instrument-contained litigation history to rely on. Any legal argument about how the instrument should be interpreted or applied in a dispute will need to build from the instrument’s text, the Therapeutic Goods Act 1989, and applicable State and Territory professional and civil law precedents. Users should monitor relevant courts and professional disciplinary bodies for any decisions that interpret the instrument or its interaction with existing legal duties.

The instrument’s focused text contains several implementation and legal risk points that require attention. These are not matters of policy judgement, but concrete operational and legal contours drawn from the instrument’s language.

1. Conjunctive conditions: substitution is only authorised where both the specific permitted circumstances in Schedule 1 Column 5 and the general permitted circumstances in Schedule 2 are satisfied (s 6). Practically, failure on any single item in either schedule invalidates the authorisation. Pharmacies must operationalise checks to confirm each requirement before substituting.

2. Definition of substitutable medicine is narrow, but silent on certain pharmaceutical properties: Schedule 1 Column 3 requires the substitutable product to be a registered 10 mg simvastatin tablet containing simvastatin as the only active ingredient. The instrument does not require demonstrable bioequivalence in release characteristics, excipient compatibility, scoring suitability, or identical formulation beyond being a registered 10 mg tablet. Pharmacists must therefore verify registered status, but the instrument leaves clinical equivalence assessment and suitability for splitting to pharmacist professional judgement (Schedule 2 item 4). That places practical burden on pharmacists to assess formulation-specific considerations that the instrument does not enumerate.

3. Tablet splitting mechanics: the instrument specifies dose unit equivalence as "half a tablet of the substitutable medicine is equivalent to one tablet of the scarce medicine" (Schedule 1 Column 4), and obliges pharmacists to provide "suitable instructions for cutting a tablet" (Schedule 1 Column 5(b)). The instrument does not define what counts as "suitable instructions" nor does it prescribe tools or standards for splitting. If a substitutable tablet lacks appropriate scoring or is not designed to be split, pharmacist professional judgement must address whether splitting is clinically appropriate and safe (Schedule 2 item 4). Pharmacies should therefore verify the physical characteristics of the 10 mg tablet and whether splitting achieves dose accuracy.

4. "Does not have access" is not defined: Schedule 2 item 2 requires that "the pharmacist does not have access to the scarce medicine". That is a fact-specific inquiry but the instrument provides no definition of "access" or evidentiary standard. Is access determined by immediate on-premises stock, distribution centre availability, or ability to order next-day? Pharmacies will need internal policies to operationalise what "lack of access" means in their context to avoid substituting when stock could feasibly be procured.

5. Prescriber prohibition mechanism: substitution is disallowed where "the prescriber has indicated on the prescription for the scarce medicine that substitution is not permitted" (Schedule 2 item 3). The instrument does not prescribe the form of such an indication. Pharmacies must determine what counts as a valid prescriber prohibition , an explicit "no substitution" notation, a specific code, or other instruction , and ensure electronic prescribing systems and paper prescriptions capture that indicator reliably.

6. Recordkeeping and notification vagueness: Schedule 2 item 7 mandates that "the pharmacist makes a record of dispensing the substitutable medicine in substitution of the scarce medicine at the time of dispensing" and item 8 requires "an established procedure to notify the prescriber ... at the time of, or as soon as practical after, dispensing." The instrument does not prescribe the content, format or retention period for the record, nor what constitutes timely notification. Pharmacies need to develop auditable procedures, document what is recorded, and define "as soon as practical" in local policy.

7. PBS and reimbursement silence: the instrument does not address subsidy, pack sizes, or claim codes. Substituting half a 10 mg tablet for a 5 mg product may raise PBS compliance, quantity, and reimbursement issues. Pharmacies must check PBS policy and claims practice to ensure substitution does not cause reimbursement errors or patient billing issues.

8. Liability and professional judgement: the instrument places substantive reliance on pharmacist professional judgement regarding patient suitability and dosage equivalence (Schedule 2 items 4 and 5). Professional judgement is a contested legal standard in negligence and disciplinary contexts. Pharmacies and pharmacists should document the basis for suitability assessments, the patient discussion, consent, and the dosing calculations used to arrive at the dispensed quantity.

9. Patient education burden: pharmacists must advise patients on dosing, cutting and differences between products (Schedule 1 Column 5). Effective communication is not trivial; splitting tablets introduces adherence risks, particularly for patients with dexterity or cognitive impairments. The obligation to obtain patient consent (Schedule 2 item 6) means patient refusal must be accommodated and alternative arrangements sought.

10. Single-item scope may produce substitution pressure: the instrument authorises substitution only for the listed scarce product and identified substitutable product class. Market actors, notably suppliers of 10 mg tablets, may see concentrated demand. Conversely, manufacturers of the scarce product see a drop in pharmacy-level demand. These market shifts are not regulated by the instrument but are material operational effects.

In practice, pharmacies implementing substitution should create checklists that map the instrument’s conjunctive requirements, record evidence of "lack of access" to the scarce medicine, capture the patient consent and advice, record the substitution contemporaneously, and implement notification mechanisms to prescribers. Failure to operationalise those controls exposes pharmacies to regulatory, professional and civil risk even though the instrument authorises substitution where conditions are met.

For pharmacists, the instrument prescribes a sequence of checks, advice and recordkeeping obligations that must be completed before lawful substitution. The process below sets out a practical compliance workflow directly traceable to the instrument’s provisions.

1. Confirm the product and prescription

• Verify that the prescription presented is for the scarce medicine listed in Schedule 1 Column 2 (ZIMSTAT simvastatin 5 mg, registration number 95672) and that the patient, or a person acting for the patient, has evidence of a valid prescription (Schedule 2 item 1).
• Check whether the prescriber has indicated that substitution is not permitted on the prescription; if such an indication is present then substitution is not authorised (Schedule 2 item 3).

2. Establish lack of access to the scarce medicine

• Determine and document that the pharmacist "does not have access to the scarce medicine" at the relevant time (Schedule 2 item 2). Develop a written policy that sets out what "lack of access" means locally: e.g., no stock on premises and no immediate supply from affiliated pharmacies that can deliver within clinically acceptable timeframe. Record the inventory search and any supplier enquiries as part of the contemporaneous record.

3. Confirm substitutable product identity and registration

• Identify the substitutable product that meets the instrument’s definition: a registered 10 mg simvastatin tablet with simvastatin as the only active ingredient and manufactured in tablet form (Schedule 1 Column 3). Confirm registration status on the Register and ensure the product is a tablet as defined by TGO 101 (s 4 note).

4. Clinical suitability and regimen equivalence

• Exercise professional judgement to determine patient suitability for receiving a half 10 mg tablet to substitute for a 5 mg tablet (Schedule 2 item 4). Consider clinical factors such as comorbidities, polypharmacy, swallowing difficulties, cognitive or dexterity impairment, and any known allergies to excipients.
• Ensure the quantity dispensed will provide an equivalent dosage regimen and duration to that prescribed for the scarce medicine (Schedule 2 item 5). Calculate the number of half tablets required and verify the total number of tablets/pack size dispensed achieves the prescribed duration.

5. Patient advice and consent

• Advise the patient or their representative of the three mandated matters before substitution: the number of dose units the patient must take based on the dose equivalence in Schedule 1 Column 4, suitable instructions for cutting the tablet, and the differences between the scarce and substitutable medicines (Schedule 1 Column 5(a)-(c)).
• Obtain and document the patient’s informed consent to receive the substitutable medicine (Schedule 2 item 6). If the patient declines, do not substitute; explore alternative options, including sourcing the scarce product or liaising with the prescriber.

6. Tablet-splitting instructions and equipment

• Provide clear, practical instructions for cutting the tablet, and where appropriate, provide or recommend suitable tablet-splitting devices. If the substitutable tablet lacks scoring or is unsuitable for splitting, assess whether splitting would produce dose inaccuracy and decline to substitute on that basis as part of your professional judgement (Schedule 2 item 4).
• Document the instructions provided and, where relevant, the provision of a splitting aid.

7. Contemporaneous recordkeeping

• Make a contemporaneous record at the time of dispensing that the substitutable medicine was dispensed in substitution for the scarce medicine (Schedule 2 item 7). The record should include, at minimum: patient identity, original prescription reference, scarce medicine identity and registration number, substitutable medicine identity and registration details, reason for substitution (lack of access to scarce medicine), calculation of dose equivalence and quantity dispensed, confirmation of patient consent, summary of advice given about cutting and differences, and prescriber contact details for notification. Retain records in a manner consistent with statutory retention requirements and auditability.

8. Notify the prescriber promptly

• Follow an established procedure to notify the prescriber at the time of dispensing, or as soon as practicable after dispensing, that the substitution has occurred (Schedule 2 item 8). Document the notification and any response. If immediate notification is not feasible, ensure the procedure specifies the timeline and method for notification and that notification occurs as soon as practical.

9. Interaction with payer systems and software

• Ensure dispensing software, invoicing and claim systems are capable of recording substitution events accurately and generating the contemporaneous record required. Confirm whether PBS or other reimbursement rules apply to the substituted dispensing and take steps to avoid incorrect claims or patient billing issues. Seek guidance from Services Australia or relevant payer administrators if necessary.

10. Internal policy and staff training

• Implement written procedures that mirror the instrument’s conjunctive requirements. Train pharmacy staff to follow the identification, documentation, advice, consent, splitting technique and notification steps. Maintain checklists or templates to ensure consistent compliance across staff and shifts.

11. Risk management and clinical governance

• Maintain a clinical governance file that records suitability assessments, adverse events or patient concerns arising from substitutions, and any follow-up with prescribers. Where patients require assistance with tablet splitting, consider alternatives such as obtaining an appropriate strength product from another supplier or liaising with the prescriber to change to an alternative therapy or formulation.

12. Audit readiness

• Ensure records are stored and indexed so they can be produced for audits by Commonwealth regulators, State and Territory pharmacy boards, or payers. The contemporaneous nature of the required record (Schedule 2 item 7) means that precise timestamps and documentary evidence of the substitution decision will be valuable in any review.

Summary checklist mapped to instrument clauses:

• Valid prescription for scarce medicine verified (Schedule 2 item 1).
• No access to scarce medicine documented (Schedule 2 item 2).
• No prescriber prohibition present (Schedule 2 item 3).
• Professional judgement of suitability recorded (Schedule 2 item 4).
• Equivalent dosage regimen and duration ensured via calculation (Schedule 2 item 5; Schedule 1 Column 4).
• Patient informed and consent recorded (Schedule 1 Column 5; Schedule 2 item 6).
• Contemporaneous record created (Schedule 2 item 7).
• Prescriber notified at or as soon as practicable after dispensing (Schedule 2 item 8).

Following the steps above implements the instrument’s conjunctive requirements and creates an auditable paper and electronic trail. Where ambiguity exists in the instrument (for example, what counts as "access" to the scarce medicine, or what suffices as "suitable instructions for cutting"), pharmacies should document reasoned local policies that are defensible in the event of regulatory review.