Greater Glasgow and Clyde Medicines

Opioid Safety - Key safety tips

Opioid choice
Patient factors
Independent check
Dose equivalence


Opioid choice

  • If patient already on an opioid: 
    • confirm correct opioid, dose and formulation before prescribing and administering
    • use at least 2 sources for medicines reconciliation, include patient where possible
    • consider current clinical status and patient factors (see below)
  • If patient opioid naïve:
    • consider indication and patient factors (see below) before prescribing


Patient factors

  • The following factors can increase susceptibility to adverse effects and toxicity:
    • renal impairment (monitor for rising creatinine during treatment)
    • hepatic impairment
    • older age
    • frailty
    • delirium
    • low body weight
    • drug interactions





  • Use minimum effective dose and actively check for signs of toxicity:
    • persistent sedation
    • vivid dreams
    • hallucinations
    • delirium
    • peripheral shadowing
    • muscle twitching/myoclonus
    • abnormal sensitivity to touch
  • Prompt recognition and treatment is required


Independent check

  • Before prescribing/administering, check:
    • right drug
    • right formulation
    • right strength
    • right dose
    • right route
  • Confusion between different opioids and IMMEDIATE and MODIFIED RELEASE oral formulations can lead to prescribing and administration errors. Refer to posters developed in the South and North sectors of NHSGGC.


Dose equivalence

  • Examples:
    • Oral oxycodone is approximately double the potency of oral morphine
    • Subcutaneous morphine is approximately double the potency of oral morphine
    • Fentanyl is approximately 100 to 150 times more potent than oral morphine (e.g. fentanyl 12microgram/hr patch approximately equivalent to oral morphine 30-60mg/24hrs)



  • Where possible:
    • Avoid high strength preparations e.g. methadone 10mg/ml oral solution, morphine 100mg/5ml oral solution, alfentanil 5mg/ml ampoule
    • Store high strength preparations at separate locations within the controlled drug cupboard

    Look out for our forthcoming series of blogs for more detailed information on opioid prescribing, case scenarios and opioid administration.


    Published 22/04/2022. Medicines Update blogs are correct at the time of publishing.

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