[Medication of the month. Adalat Oros 60 mg]

The release of Adalat Oros 60 on the Belgian market was justified since it has been clearly demonstrated that the dosage of 60 mg significantly increases the proportion of responders to nifedipine monotherapy. This gives us the opportunity to briefly review the history of nifedipine and to describe the original and ingenious galenic controlled-release formulation known as Oros (Gastrointestinal Therapeutic System, or GITS in the anglo-saxon world). Cleary, nifedipine is a potent calcium antagonist the action of which is now smooth and devoid of the usual ups and downs observed with the regular capsules, even in their Retard form. These abrupt changes in plasma concentrations, with the subsequent variations in heart rate and blood pressure, were dangerous and bothersome. Oros allows plasma concentrations of nifedipine to plateau for at least 24 hours after oral administration. This reduces the incidence of side-effects which remain those classically attributable to calcium antagonists (i.e.: flushes, headaches); interestingly, they tend to appear early after treatment initiation which allows to easily ascribe them to the drug and to quickly assess tolerance. The INSIGHT trial compared the effects on nifedipine Oros to those of a classical diuretic combination (hydrochlorothiazide-amiloride) in 6321 hypertensives who had at least one additional risk factor for cardiovascular disease. The rate of the primary outcome (a composite of cardiovascular death, myocardial infarction, heart failure, stroke) was similar in the two treatment groups, but nifedipine was superior among the subgroup of diabetics. Substudies suggested that nifedipine slows the progression of atherosclerotic lesions (carotid and coronary arteries), preserves renal function, and prevents the development of new diabetes.