The relative potency of morphine when given by various routes is given below:
Route  | Potency relative to oral morphine  | 
oral morphine  | 1  | 
rectal morphine  | 1  | 
subcutaneous morphine  | 2  | 
intravenous morphine  | 3  | 
subcutaneous diamorphine  | 3  | 
i.e. 3mg oral morphine is equivalent to 1mg of subcutaneous diamorphine
Check summary of product characteristics before prescribing any drugs mentioned.
Reference:
Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.