Investigations on the Metabolism and Protein Binding of Nifedipine

Schlossmann, K; Medenwald, H; Rosenkranz, H.

doi:10.1007/978-3-662-39666-7_6

Cited by 9 publications

(4 citation statements)

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“…The biphasic elimination of nifedipine accounts for its long duration of action since nifedipine has a beta half life of 2.5 to three hours and a terminal slow half life of five hours. 17 The effect of nifedipine on shunting is due to the drug itself not to the solvent used to prepare it since group E dogs given the solvent itself did not show any change in intrapulmonary shunting.…”

Section: Discussionmentioning

confidence: 95%

Intrapulmonary shunting during deliberate hypotension with nifedipine, diltiazem and labetalol in dogs

et al. 1985

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Section: Discussionmentioning

confidence: 95%

Intrapulmonary shunting during deliberate hypotension with nifedipine, diltiazem and labetalol in dogs

et al. 1985

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“…administration is determined by hepatic blood flow, the intrinsic metabolic activity of the liver and protein binding (Wilkinson et al, 1975). Nifedipine is highly bound to plasma proteins (Schlossmann et al, 1975) and the mean serum albumin was significantly lower in the elderly. However, albumin shows low affinity, high capacity binding of basic drugs so that alterations in albumin concentrations do not usually result in marked changes in binding (Routledge, 1986).…”

Section: Discussionmentioning

confidence: 99%

Age‐related changes in the pharmacokinetics and pharmacodynamics of nifedipine.

Robertson

Waller

Renwick

et al. 1988

Brit J Clinical Pharma

120

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1 The effects of age on the pharmacology of nifedipine were investigated in 11 young and six elderly normotensive volunteers. 2 Following 2.5 mg of nifedipine i.v. the plasma clearance of nifedipine was 348 ± 83 (s.d.) ml min-1 in the elderly compared with 519 ± 125 ml min'-in the young (P < 0.05) and the AUC in the elderly was significantly greater at 125 ± 28 ng mlF-I h compared with 83.9 ± 19 ng ml-' h (P < 0.05). The V1, was similar in both age groups.3 Following 10 mg oral sustained release nifedipine the AUC was 281 ± 64 ng ml-l h in the elderly compared with 136 ± 56 ng ml-' h in the young (P < 0.002) and Cmax in the elderly was significantly greater at 36.8 ± 11.8 ng ml-' compared with 22.3 ± 5.8 ng ml-' (P < 0.05). The trend towards an increased bioavailability in elderly subjects (36%) was supported by a significantly lower nitropyridine metabolite/nifedipine ratio in the elderly. 4 Absorption rate limited kinetics of the sustained release formulation were indicated by the prolonged tv2 compared with i.v. administration. In the elderly t½2 (oral) was significantly greater than in the young (elderly 6.7 ± 2.2 h, young 3.8 ± 1.4 h, P < 0.05). 5 Haemodynamic changes in the young were confined to a tachycardia following i.v. administration. In the elderly, supine BP fell significantly following both oral and i.v. nifedipine while the heart rate remained unchanged. 6 The results suggest that a reduction in first pass metabolism and clearance of nifedipine and impaired baroreceptor function in the elderly may both contribute to its increased hypotensive effect in this age group.

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“…It is reported that in rats and dogs more than 90% of orally administered nifedipine was absorbed when labelled compound was adminstered in a drug form identical to the conventional one (Patzschke et al 1975). Schlollmann et al (1975) reported that in rats, metabolism of nifedipine was very rapid and 40% of absorbed nifedipine changed to inactive metabolites within 30 min after oral administration.…”

Section: Discussionmentioning

confidence: 99%

Pharmacokinetics and pharmacodynamics of conventional and slow release forms of nifedipine in essential hypertensive patients.

Imai

Abe

Sasaki

et al. 1986

Tohoku J. Exp. Med.

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In patients with essential hypertension, the pharmacokinetics of nifedipine in 2 forms (capsule, 10 mg nifedipine dissolved in an organic solvent ; slow release tablet, 20 mg nifedipine) and their pharmacodynamic effectiveness on arterial pressure were studied. The maximum plasma concentration was higher and achieved more rapidly after application of the capsule than after the retard tablet (p <0.01). The plasma half-time of nifedipine in the capsule was shorter than that in the retard tablet (p <0.05). The absorption rate of nifedipine from the capsule tended to be larger than that from the retard tablet. Plasma concentrations of nifedipine, measured 12 hr after the dosing of the retard tablet during chronic treatment, were not different from those after the acute administration of the retard tablet, suggesting that no accumulation of nifedipine occurs. The capsule of nifedipine elicited prompt and profound hypotension with short duration, while the retard tablet produced a hypotensive effect with relatively slow onset and long duration. Arterial pressure reduction was maintained throughout the day using 12 hourly dose of the retard tablet. During the chronic treatment the maximum hypotensive effect was observed 4 weeks after the start of treatment. Twelve hourly administration of the retard tablet is a convenient regimen for the long-term control of mild to severe essential hypertension.nifedipine ; slow release form ; conventional form ; antihypertensive therapy ; essential hypertension Nifedipine is a potent vasodilator, which relaxes vascular smooth muscle probably by its inhibitory effect on the transmembrane influx of calcium (Fleckenstein et al. 1972 ). It has been demonstrated that this drug exerts a prompt and marked hypotensive effect when administered to hypertensive patients (Murakami et al, 1972;Aoki et al, 1976;Guazzi et al. 1977;Pedersen and Mikkelsen 1978;Imai et al. 1980) and the drug has been accepted as a critical therapeutic for several forms of hypertension (Guazzi et al. 1983;Massie et al. 1984; Muhller et

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Investigations on the Metabolism and Protein Binding of Nifedipine

Cited by 9 publications

References 0 publications

Intrapulmonary shunting during deliberate hypotension with nifedipine, diltiazem and labetalol in dogs

Intrapulmonary shunting during deliberate hypotension with nifedipine, diltiazem and labetalol in dogs

Age‐related changes in the pharmacokinetics and pharmacodynamics of nifedipine.

Pharmacokinetics and pharmacodynamics of conventional and slow release forms of nifedipine in essential hypertensive patients.

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