7. Notwithstanding the existence of arrangements under which a dispensing doctor (D) is to provide pharmaceutical services to a patient (P), if D determines that P requires a drug or appliance that is available on prescription from an NHS chemist—
(a)D may with the agreement of P issue; or
(b)if P so requests, D must not unreasonably refrain from issuing,
a prescription form that P may present to any NHS chemist instead of D supplying that drug or appliance to P.