Controlled Drug Prescribing

The legislation of Controlled Drugs (CDs) in the UK has undergone many changes in recent years in an effort to improve patient and staff safety in relation to CDs. It is essential that a complete audit trail for CDs, from their procurement by pharmacy to administration / supply to patients or their return to pharmacy and/or destruction, is maintained.

Guidance on the regulations, classification and scheduling of CDs can be found here. Of note is that pregabalin and gabapentin, like midazolam, are now classified as Schedule 3 CDs and as such, come under the regulations governing CDs. 

Refer to the Code of Practice for Medicines Governance – Controlled Drugs (link only active if accessing via NHS network) for further details or for discharge prescriptions on Arran/Cumbrae.

Prescription requirements for schedule 2 and schedule 3 CDs

• Discharge prescriptions must be on the electronic CD discharge prescription generated by the Hospital Electronic Prescribing and Medicines Administration (HEPMA) OR written on a separate copy of the approved Immediate Discharge Letter (IDL).
• Check with pharmacy for local procedure for provision of CD prescriptions. See Appendix 6 for contact details.
• On the discharge prescription the following details must be included (N.B. addressograph adhesive labels not allowed):
  • The patient's name, CHI number and address.
  • The name, strength of the drug and form (tablets, mixture, vial, patch, etc.).
  • The total quantity of dose units (i.e. number of tablets, unit dose vials, injections, patches or volume (ml) of liquids) in words and figures.
  • The dose / time to be taken by the patient (good practice point - also include dose frequency).
  • The date of the prescription.
  • The prescriber's signature.
• Normally the supply quantity given at discharge is 7 days (restricted to a maximum of 14 days).
• Ward stock must NOT be used to supply patients on discharge.

Examples 

• Morphine 10mg tablets: take one every four hours if required for breakthrough pain. Please supply 28 (twenty-eight) 10mg tablets.
• Fentanyl 25microgram/hour patch: apply one patch every 72 hours. Please supply 3 (three) 25microgram patches.
• Zomorph 10mg capsules: Take one capsule twice daily. Please supply 14 (fourteen) 10mg capsules.
• Oxycodone 5mg/5ml liquid: Take 5mg four times a day. Please supply 250ml (two hundred and fifty millilitres).
• Tramadol 50mg capsules: take two capsules four times a day. Supply 56 (fifty-six) 50mg capsules.
• Temazepam 10mg tablets: take one tablet at night. Supply 7 (seven) 10mg tablets.

Prescribers must clearly state on the prescription the quantity to be supplied of each different formulation. For example:

• Morphine injection 50mg subcutaneously via a syringe driver over 24 hours. Please supply 10 (ten) morphine 10mg/ml amps and 5 (five) morphine 30mg/ml amps.

The following are available strengths of commonly prescribed CDs (not an exhaustive list) which are also included on the NHSAAA Medicines Formulary:

Zomorph^® (Morphine MR) capsules 10mg, 30mg, 60mg, 100mg, 200mg

MST^® (Morphine MR) tablets 5mg, 15mg

Morphine Immediate Release (IR) tablets 10mg, 20mg, 50mg

Morphine injection 10mg/ml, 15mg/ml, 30mg/ml

Oxypro^® (Oxycodone MR) tablets 5mg, 10mg, 15mg, 20mg, 30mg, 40mg, 80mg

Shortec^® (Oxycodone immediate release) capsules 5mg, 10mg, 20mg

Oxycodone liquid 5mg/5ml

Matrifen^® (Fentanyl transdermal) patches 12, 25, 50, 75, 100micrograms

CD prescribing – lessons learned

A number of incidents have been reported involving confusion between similar sounding names and misinterpretation around standard and modified release (MR) products. DATIX reports show a number of incidents where millilitres and milligrams have been confused in liquid preparations.

For all liquid preparations:

• Ensure that the strength is clearly stated on the prescription.
• Prescribe the dose in micrograms, milligrams, or grams, as appropriate, and not as the volume, to avoid misinterpretations if the medicine is available in different strengths.

Common errors occur due to confusion between IR and MR preparations. Oral MR opioid preparations should be prescribed by brand to minimise the risk of confusion and error in dispensing and administration.