Comparison of Early Side Effects with Amlodipine and Nifedipine Retard in Hypertension

Abstract

The frequency and severity of adverse effects during the first 14 days of treatment with amlodipine (5 mg once daily), nifedipine retard (20 mg twice daily) or placebo were compared in a multicentre, three-way, cross-over study involving 97 patients with mild-to-moderate hypertension. All three groups of patients were well matched for age, sex and baseline blood pressure. Amlodipine and nifedipine retard produced highly significant and comparable reductions in blood pressure, indicating that the doses were therapeutically equivalent. The incidence of adverse effects considered to be definitely or probably related to nifedipine retard treatment (41%) was significantly higher than for placebo (16%, p < 0.01) or amlodipine (27%, p < 0.05). There were no significant differences in the incidence of vasodilator-related adverse effects between amlodipine and placebo. In contrast, headache, flushing and dizziness were reported more frequently by patients while on nifedipine retard than on placebo or amlodipine. The convenience of once-daily dosing, together with a lower incidence of adverse effects, with consequently fewer withdrawals from therapy, suggests that amlodipine has clinical advantages over nifedipine retard in the treatment of hypertension.

A Comparison of Two Long-Acting Vasoselective Calcium Antagonists in Pulmonary Hypertension Secondary to COPD

“…Amlodipine is a new calcium antagonist with very high vascular (arteriolar) selectivity, prolonged dura¬ tion of action that allows once daily administration, and it has a lower incidence of side effects than nifedipine. 25 Felodipine extended release (ER) is an ER preparation that has similar advantages. Both preparations have a relatively small peak to trough plasma concentration difference across a 24-h pe¬ riod, which may lead to a reduced incidence of side effects.26 These agents are therefore potentially suit¬ able for prolonged treatment of PH secondary to COPD.…”

Tolerability of Amlodipine

“…lSI These adverse events, in particular peripheral oedema, are reported to be dose related. 11,5,6] In our study, no substantial difference was found in the incidence of adverse events, including peripheral oedema, at the 2 different dose levels of amlodipine (5 or IOmg). It should be borne in mind, however, that 12 of the 16 studies included in this meta-analysis initiated amlodipine treatment with a daily dose of 5mg; if the drug was poorly tolerated at this dose it is unlikely that the physician would have increased the dose.…”

“…1,4) Several studies have demonstrated that amlodipine is a well tolerated drug, associated with only mild and infrequent adverse events. [1,[4][5][6] However, it is only by pooling adverse event data from a substantial number of small scale studies that we can reach firm conclusions regarding the tolerability of investigational or newly launched drugs. Findings obtained in this manner are more likely to be representative of a drug's true tolerability than those derived from a single clinical trial of the same drug.…”

Efficacy and Tolerability of Amlodipine 5mg Monotherapy in Mild to Moderate Essential Hypertension

“…The occurrence of adverse events severe enough to require treatment interruption was low (4.9%). Previous comparative studies have shown that the incidence of adverse events during amlodipine treatment is significantly lower than that observed with other dihydropyridines such as nifedipine [19] or nitrendipine. (20] The results of this study also showed that the antihypertensive effect of amlodipine 5mg monotherapy was not associated with reflex tachycardia.…”