You are here Home Guidance and resources Resources Guidance Section 19A: Guidance for industry Version history Supplying substitute medicines when registered medicines are unavailable or in short supply Last updated 23 March 2023 Listen Print Share LinkedIn Twitter Facebook Email Loading... Version history Version Description of change Author Effective date V1.0 Original publication Pharmacovigilance and Special Access Branch (PSAB) and Regulatory Guidance Section October 2017 V1.1 Updates to incorporate legislative amendments and minor corrections Pharmacovigilance Branch (PB) March 2023 Previous Example Dear Healthcare Professional Letter