Opioids, benzodiazepines and other Schedule 8 medicines

Prior written authorisation is required to prescribe where any of the following criteria are met:

• Health practitioner:
  • medical practitioners where any of the other criteria are met; or
  • dentists or nurse practitioners prescribing for more than 14 days; or
  • all other prescribers.
• Patients:
  • under 18 years of age; or
  • with a history of substance abuse within the previous five years or persons recorded as Oversupplied or Drug Dependent.
• Total daily dose:
  • opioids over 90 mg morphine equivalents; or
  • immediate release opioids over 45 mg morphine equivalents.
• Drug:
  • methadone; or
  • alprazolam; or
  • flunitrazepam; or
  • other S8 medicines not covered elsewhere in this Code.
• Injectable formulations;
• Therapeutic Goods Administration (TGA) unapproved products or indications.

To determine if treatment is inside the Code, practitioners must determine the total daily opioid dose as morphine equivalents (MEq). Written authorisation is required before prescribing a total daily dose of opioids over 90mg morphine equivalents.

For the purposes of the Code, an approximate guide to the doses of opioids equivalent to an oral morphine dose of 90mg include:

For more information on dose equivalents prescribers can use the Dose Conversion Calculator (Excel 757KB).

This information is a guide to calculating morphine equivalents only. It is not intended to be used alone to switch patients from one opioid to another.

Methadone

All prescribing of methadone requires prior authorisation of the Department of Health.

Methadone is a high-risk, potent opioid, with complex pharmacokinetics. Deaths attributed to methadone are linked to prescribing by inexperienced practitioners, lack of consideration of the long and variable half-life, and use of inappropriately high doses. Dose conversion and titration between methadone and other opioids is complex and should be discussed with a pain specialist or pain management clinic.

Flunitrazepam

All prescribing of flunitrazepam requires the prior authorisation of the Department of Health.

For an authorisation to be considered, applications must be accompanied by evidence support from a consultant medical practitioner in a relevant specialist field.

Alprazolam

All prescribing of alprazolam requires the prior authorisation of the Department of Health.

Concerns of widespread abuse and misuse of alprazolam led to the recent inclusion of this benzodiazepine in Schedule 8. Alprazolam is no longer considered first-line treatment or suitable for long-term management of anxiety or panic disorder. Alprazolam is also associated with significant adverse effects including over sedation, falls, cognitive impairment, dependence, toxicity and death.

To apply for authorisation, practitioners must apply in writing using the Application for authorisation: Opioids, benzodiazepines and other Schedule 8 medicines form (Word 850KB).

Applications must be completed, contain all required information and any relevant attachments or documents. Where consultant medical practitioner support is required for approval, sufficient written evidence of this support must be included, at the time of application.

A Certification of Nurse Practitioners to prescribe Schedule 8 medicines in a collaborative care setting form (Word 785KB) is required to accompany the Application for authorisation for Nurse Practitioners applying to prescribe Schedule 8 medicines for longer than 14 days.

Records of Schedule 8 medicines dispensed at all Western Australian Pharmacies are collected and maintained by the Department of Health. These records are routinely reviewed for compliance with the Regulations and the Schedule 8 Prescribing Code.

In particular, the records are scrutinised to identify instances of problematic patient use and bring these to the attention of prescribers. The Department will contact prescribers in any case where:

• prescribing is not consistent with the Code
• authorisation is required but not obtained
• prescribing is not consistent with the authority issued
• multiple prescribers (at different practices) are involved.