Background Nifedipine has been available worldwide since the early 1980's as a treatment for hypertension and angina pectoris. However, over time, the drug formulation has undergone a number of modifications to improve the pharmacokinetic profile and achieve a once daily dosing régimen. Nifedipine in the GITS formulation is the most studied of the once daily formulations and it is registered in most major countries worldwide. Nifedipine GITS employs osmotic push pull technology but there is a wide range of alternative drug delivery systems including, for example, erosive tablet technology, hydrophilic matrix tablets, a monolithic enteric coated like tablet with an erosive polymer matrix, an eroding matrix and a monolayer matrix tablet. Results This presentation is derived from a comprehensive review of the published literature to date. Pharmacokinetic and bioequivalence studies have failed to show that any of the other formulations is consistently bioequivalent to nifedipine GITS. With respect to pharmacodynamics, limited data from comparative clinical studies show significant differences in favour of the nifedipine GITS formulation in terms of blood pressure control and activation of the sympathetic nervous system. For example, in the study by Brown and Toal (2007) when patients were switched from Nifedipine GITS to Coractennifedipine a rapid decline in blood pressure was noted accompanied by an increase in heart rate and plasma norepinephrine at the time of peak plasma drug concentration. Finally, nifedipine GITS is the only once daily formulation with clinical trial outcome evidence in both hypertension (INSIGHT) and angina pectoris (ACTION). Conclusions The evidence base confirms that Nifedipine GITS should be considered to be the “reference” formulation. Furthermore, for both pharmacokinetic and therapeutic reasons, the evidence indicates that patients should not be switched between once daily formulations of nifedipine.