Switch from ACE inhibitor, calcium channel blocker or beta-blocker to candesartan cilexetil: better efficacy and toterability - SWITCH study (German part)

Background and objective: Lack of efficacy in the treatment of hypertension with only one drug presents a problem in general practice and often requir es switching to another type of drug, because higher dosage of currently us ed antihypertensives increases the frequency of side effects. Angiotensin I i antagonists are well tolerated and there is no evidence of dose-related i ncrease in side effects. This study in 574 hypertensives under therapy with ACE inhibitors, beta -blockers or calcium channel blockers was under-taken to determine whether direct switching to the Angiotensin Ii-antagonist can desartan cilexetil at its maximal dose of 16 mg is as effective and tolerab le as starting therapy with candesartan cilexetil 8 mg followed by up-titra tion to 16mg after 4 weeks. Patients and methods: 258 men (mean age 57 +/- 11 years) and 316 women (58 +/- 12) with essential hypertension (blood pressure < 180/95 mm Hg) under a mbulatory therapy with ACE-inhibitors, beta -blockers or calcium channel bl ockers with inadequate efficacy or tolerability were switched to monotherap y with candesartan cilexetil. Half of the patients were treated with 8mg fo r 4 weeks (n=284), the other half received 16mg (n=290). Both groups then w ere treated with candesartan cilexetil, 16mg, for further 4 weeks. Choice o f treatment was doubly blinded and randomised. Results: After 4 weeks significant blood pressure reduction was observed in both treatment groups (p < 0.0001 for each pretreatment group). A tendency for more adequate blood pressure reduction under initial therapy with cand esartan cilexetil 16mg was observed. There was a small further blood pressu re reduction in both treatment groups after 8 weeks. In comparison with the previous medications the proportion of patients with blood pressure reduct ion ( 90 mo Hg diastolic was doubled in both treatment arms after 4 weeks: after initial dose of candesartan cilexetil 8mg from 36.7% to 78.8%, after initial dose of candesartan cilexetil 16mg from 43.9% to 81.1%. Clinically relevant side effects were not observed. Conclusion: Switching of antihypertensive monotherapy with ACE inhibitors, beta -blockers or calcium channel blockers to candesartan cilexetil 8mg or 16mg under ambulatory conditions is safe and equally well tolerated reduces blood pressure.