'(1A) The Minister shall only exercise the power to make regulations under subsection (1)(f) of this section in the case of registered nurses, or registered nurses belonging to a class of registered nurses, if the Minister, after having had regard to the nature and purpose of the controlled drug concerned (including any deleterious effects which may arise from the misuse thereof), is satisfied that it is reasonably safe to permit the issue by registered nurses, or registered nurses belonging to a class of registered nurses, of prescriptions for that drug.',