Dihydropyridines, felodipine, and PHARMAC

Calcium antagonists have evolved as useful drugs in the treatment of hypertension and angina. Dihydropyridines are the largest subgroup and various products have been marketed. Safety concerns have largely been allayed by comparative outcome trials but concern remains over short-acting products. In New Zealand, many patients requiring fully subsidised dihydropyridines have had several changes of product imposed due to successive reference pricing and sole-supply arrangements, along with deregistering and reregistering of generic felodipine. Some narrowly avoided a complete loss of access to a suitable low dose of any dihydropyridine. Generic substitution and sole-supply arrangements may make useful savings but can leave the supply of key pharmaceuticals vulnerable and impose significant loss in quality of healthcare from multiple changes in pharmaceutical preparation.