Translating safety, efficacy and compliance into economic value for controlled release dosage forms

Advanced controlled release (CR) dosage forms are relative newcomers to pharmaceutical markets, and few studies relate their efficacy, safety or compliance benefits to economic value. This literature review was undertaken to assess the cost effectiveness of CR dosage forms using such measures as purchase costs, total treatment costs, and economic value of improved therapeutic outcomes compared with those with non-CR dosage forms. Three therapeutic areas were examined: cardiovascular therapy, pain management and estrogen replacement therapy. In cardiovascular therapy, prescription costs of sustained release (SR) verapamil were significantly higher than for conventional release verapamil. However, these were more than offset by lower physician, hospital and laboratory expenditures for the SR group, in whom compliance was superior. Similarly, patients receiving SR diltiazem had better prescription refill compliance than those using a conventional formulation of the drug, as well as significantly lower aggregate healthcare costs during a 1-year study period. These lower costs with both SR verapamil and diltiazem may relate to better compliance. CR nifedipine has lower daily acquisition costs than the conventional form, simplifies the dosage regimen to once daily, extends the indications of the drug to hypertension as well as angina, and reduces vasodilatory adverse effects by reducing peak plasma drug concentrations and the postdose rate of increase in concentration. Compared with oral clonidine given twice daily, transdermal clonidine, given once weekly, had higher purchase costs, but was associated with improved compliance, reduced adverse effects (due to control of plasma concentrations), and lower nondrug health costs, such as physician, hospital and laboratory costs. Lower costs were also found for once daily oral formulations of various antihypertensives, suggesting that the economics of both types of CR dosage forms related to compliance. CR metoprolol 50 or 100mg and conventional release atenolol 50mg, each given once daily, provided effective beta1-adrenoceptor blockade. The conventional formulation caused deterioration in the sense of well-being that was temporally associated with sharp peaking of its plasma concentrations. Such peaking did not occur with either dose of CR metoprolol, nor did any deterioration in the sense of well-being. Transdermal nitroglycerin (glyceryl trinitrate), compared with long-acting oral nitrates, improved quality of life (QOL) {despite a higher incidence of some adverse effects, such as headache, dizziness and skin irritation}. Furthermore, in some studies, this formulation reduced angina attacks, sublingual nitroglycerin use, and hospitalisation or emergency room use. Cost comparisons between transdermal products favoured those that have superior adhesion.(ABSTRACT TRUNCATED AT 400 WORDS)