Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Potent pharmacokinetic drug interactions

Antipsychotic pharmacokinetics can be significantly affected by concomitantly administered enzyme inducers or inhibitors. Smoking is a potent inducer of hepatic enzymes and may increase antipsychotic clearance by as much as 50%. The published literature may be consulted for a listing of antipsychotic drug interactions. [Pg.826]

Even more subtle effects arise for drug interactions of a non-chiral drug with a chiral one. Phenylbutazone is not chiral in itself but it can interact with a chiral drug, warfarin, to change the activity of the latter. Phenylbutazone inhibits the oxidative metabolism of the (S)-(-) form of warfarin, (which is five times more potent than the (/ )-(+) form) and thereby decreases its clearance. Conversely, phenylbutazone induces the enzymatic reduction of the (/ ) form thus increasing the clearance.93 Analysis of total warfarin may indicate little departure from normal pharmacokinetics, but the distribution of eutomer and distomer will have changed markedly. [Pg.775]

The H2-receptor antagonists inhibit acid production by reversibly competing with histamine for binding to H2 receptors on the basolateral membrane of parietal cells. Four different H2-receptor antagonists, which differ mainly in their pharmacokinetics and propensity to cause drug interactions, are available in the United States cimetidine (Tagamet), ranitidine (Zantac), famotidine (Pepcid), and nizatidine (Axid). These drugs are less potent than proton-pump... [Pg.264]

The efflux transporter P-gp is a major determinant of the pharmacokinetics and pharmacodynamics of loperamide, a potent opiate. The main reason that loperamide does not produce opioid CNS effects at usual doses in patients is a combination of slow dissolution, first-pass metabolism, and P-gp-mediated efflux, which prevents brain absorption, perhaps contributing to its low addiction potential. Loperamide produced no respiratory depression when administered alone, but when administered with a P-gp inhibitor, respiratory depression occurred, which could not be explained by increased plasma loperamide concentrations. This effect demonstrates the potential for important drug interactions by inhibition of P-gp efflux transporter. The lack of respiratory depression produced by loperamide, which allows it to be safely used therapeutically, can be reversed by a drug causing P-gp inhibition, resulting in serious toxic and abuse potential. [Pg.1010]

In addition to pharmacokinetic drug-drug interactions, pharmacodynamic effects have been reported as well. Halothane increases the susceptibility to ventricular arrhythmias under theophylline therapy as a result of increased sensitivity of the myocardium to endogenous catecholamine release by theophylUne. Ketamine lowers the theophyUine seizure threshold. Benzodiazepines Uke midazolam, diazepam, lorazepam, and Uurazepam increase the central nervous system concentration of adenosine, a potent central nervous system depressant. As theophyUine also blocks adenosine receptors, it counteracts benzodiazepine-induced sedation, resulting in increased dosage requirements for these compounds. ... [Pg.218]

Macromolecules such as proteins and nucleic acids form the sites at which drugs interact. Knowledge of three-dimensional conformations assists in the design of analogues that are more potent and have improved pharmacokinetic properties. Furthermore, the structural analyses of protein receptors and enzymes adds to the knowledge of biological systems, and therefore assists in identifying novel... [Pg.1100]


See other pages where Potent pharmacokinetic drug interactions is mentioned: [Pg.189]    [Pg.44]    [Pg.509]    [Pg.529]    [Pg.300]    [Pg.22]    [Pg.216]    [Pg.64]    [Pg.143]    [Pg.267]    [Pg.268]    [Pg.1080]    [Pg.58]    [Pg.60]    [Pg.182]    [Pg.484]    [Pg.389]    [Pg.2263]    [Pg.21]    [Pg.624]    [Pg.848]    [Pg.445]    [Pg.446]    [Pg.494]    [Pg.495]    [Pg.749]    [Pg.821]    [Pg.837]    [Pg.1180]    [Pg.230]    [Pg.60]    [Pg.126]    [Pg.3]    [Pg.533]    [Pg.516]    [Pg.3]    [Pg.487]    [Pg.47]    [Pg.23]    [Pg.178]    [Pg.42]    [Pg.156]    [Pg.299]   
See also in sourсe #XX -- [ Pg.55 ]




SEARCH



Drug pharmacokinetic

Drugs pharmacokinetics

Pharmacokinetic interactions

Pharmacokinetics interactions

Potent

Potentization

© 2024 chempedia.info