Apparatus for drug administration; Apparatus for use in the delivery of drugs; Drug delivery apparatus; Drug delivery devices; Apparatus for administering drugs by inhalation; Implantable subcutaneous drug delivery devices; Metering pumps for delivering drugs in measured quantities (medical use); Apparatus for administering medicines; Apparatus for medicinal use; Apparatus for the administration of powdered medicines; Devices for use in the administration of medicines; Transdermal drug delivery apparatus; Apparatus for controlling medical infusions; Apparatus for measuring flow rates in medical infusions; Apparatus for monitoring flow rates in medical infusions; Apparatus for regulating flow rates in medical infusions; Hypodermic needles for use in infusion therapy