Guinness's prescriptions were due.
Best I could get was
Vetmedin Capsules (which are still available despite my vets advice) 2.5mg Â£31.45 for tub of 100 - or 32p each
Fortekor flavor 5mg - 69p each
Frusemide 20mg - 2p each
Took these prices and got a further 5% off from Petmeds.