You can claim the tax amounts that are added to your medicinal cannabis, as CRA states in the Income Tax Folio on Medical Expenses:
The CRA takes the view that eligible medical expenses include the goods and services/harmonized sales tax (GST/HST) that is added to the cost of certain medical services.
There is nothing specific from the CRA that says the shipping costs can also be included as a valid medical expense. You may want to contact the CRA directly and ask for clarification on claiming these costs.
From the CRA Medical Expenses guide:
Medical cannabis (marihuana) – the amounts paid for cannabis, cannabis oil, cannabis plant seeds, or cannabis products purchased for medical purposes from a holder of a licence for sale (as defined in subsection 264(1) of the Cannabis Regulations). The patient must be a holder of a medical document (as defined in subsection 264(1) of the Cannabis Regulations). The Cannabis Regulations require that the patient be registered as a client of the holder of a licence for sale and require the patient to make their purchases from the holder they are registered with.