Search results for "PHARMACOKINETICS"
showing 10 items of 458 documents
Pharmacokinetic rationale for switching from donepezil to galantamine.
2001
Galantamine, the most recently approved acetylcholinesterase inhibitor (AChEI) for use in the United States, has allosteric modulating activity at nicotinic receptors and inhibits acetylcholinesterase. This dual mechanism of action may make galantamine an attractive option for patients with Alzheimer's disease who have not benefited from their current therapy; thus, methods for switching patients from donepezil or rivastigmine to galantamine are needed. Protocols for switching patients from one AChEI to another must consider both the time required for washout of the first drug and the rate of dose escalation of the second drug. Both issues depend on the pharmacodynamics, pharmacokinetics, a…
Relevancia clínica de la selectividad de los inhibidores del cotransportador sodio-glucosa tipo 2
2016
Selectivity is the property of a drug to preferentially bind to a biological structure. Most drugs can bind and stimulate or inhibit more than one system. Therefore, it is important that they are selective for the intended site and that the doses used do not have effects on other sites, which could provoke adverse reactions. Selectivity is assessed through in vitro experiments on organs or isolated cells. If the aim is to compare drugs, the experiment should be conducted in the same tissue and with the same design. Even so, the results cannot be directly extrapolated to clinical practice due to the influence of pharmacokinetic properties, which allow an adequate dose of the drug to reach th…
Minimum effective dose for antidepressants - an obligatory requirement for antidepressant drug evaluation?
1996
Extensive clinical trials are required for registration and approval of new antidepressants in most countries including the requirement that a minimal effective dose should be determined. The rationale for this requirement is to avoid the use of unnecessarily high doses. The implication is that for every antidepressant, a dose exists that serves as a threshold, below which all doses are not effective or are clearly less effective in treating a major depressive episode. Dose titration and fixed dose studies are used to determine the minimal effective dose, but both strategies have limitations and often do not allow definite establishment of a clear-cut minimal effective dose. The effort of e…
Therapeutic drug monitoring for antidepressant drug treatment.
2012
The aim of antidepressant drug treatment is to produce remission without causing adverse effects during the acute phase of the illness and to prevent relapses or recurrences during continuation or maintenance therapy. To achieve these goals, drug choice and dosage must be optimized for each patient individually. Therapeutic drug monitoring (TDM), which is based on the assumption that clinical effects correlate better with blood levels than doses, can be helpful. When using tricyclic antidepressant drugs TDM enhances safety and efficacy. For newer antidepressant drugs, however, it is a matter of debate to which extend TDM can have beneficial effects. For many antidepressants there exist care…
Amorphous Ropinirole-Loaded Mucoadhesive Buccal Film: A Potential Patient-Friendly Tool to Improve Drug Pharmacokinetic Profile and Effectiveness
2020
Nowadays the therapeutic strategies to manage Parkinson&rsquo
Retarded Elimination of a High-Molecular Enzyme-Substrate-Complex after Hydroxyethyl-Starch-Infusion
1978
During a pharmacokinetic study with hydroxyethyl starch we found, that this plasma substitute induces a regular increase of serum amylase. In 54 patients after infusion of 500 ml 6% hydroxyethyl starch (HES) an increase of serum amylase was observed, which in 51 cases exceeded the upper limit of normal (190 U/l). In most cases serum amylase reached values twice as high as the basal value. Renal function influenced duration of increased serum amylase values, but did not influence maximum increases (201 ±15 U/l; mean ± SEM). In patients with advanced renal failure (GFR = 2–10 ml/min) serum amylase was still markedly elevated after 72 hours (298 ± U/l; mean ± SEM). In patients with normal rena…
A preliminary study on the distribution of morphine and its glucuronides in the subcompartments of blood.
1998
[Abstract ] The distribution of morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) in whole blood, plasma, and packed erythrocytes was studied. Parameters investigated were the hematocrit values (10, 42, 44, and 71%) and the water content of the samples. The blood-to-plasma ratio of morphine concentrations was unaffected by variations in hematocrit and water content, whereas the corresponding ratios for M3G and M6G were strongly influenced. Ratios were 0.53 to 0.65 and 0.52 to 0.62 in specimens with average hematocrit values (42 and 44%, respectively), and the ratios were 0.81 or 0.89 (hematocrit 10%) and 0.27 or 0.28 (hemalocrit 71%) in blood samples with different he…
Elimination kinetics of synthetic interferon inducer tilorone in experimental animals
2017
Objective. A comparative investigation was carried out on the kinetics of [3H]-tilorone ([3H]-I) excretion in rats and mice. Materials and method. Kinetics of urinary and biliary excretion of [3H]-I in rats and mice was studied following a single oral and intravenous administration. The excretion mass balance was monitored in the faeces and urine of rats and mice for 5 and 10 days, respectively. Radioactivity was determined in the samples of excreta using a liquid scintillation counter. Results. In rats, [3H]-I were nearly fully (~80%) eliminated with excreta in 5 days, indicating a lack of any significant accumulation of the drug in the body. Faecal excretion of tilorone predominated (69.0…
Differences in tissue distribution of iron from various clinically used intravenous iron complexes in fetal avian heart and liver.
2015
Abstract Nanomedicines are more complex than most pharmacologically active substances or medicines and have been considered as non-biological complex drugs. For nanomedicines pivotal pharmacokinetic properties cannot be assessed by plasma concentration data from standard bioequivalence studies. Using intravenous iron complexes (IICs) as model we show that fetal avian tissues can be used to study time dependent tissue concentrations in heart and liver. Clear differences were found between equimolar doses of sucrose, gluconate or carboxymaltose coated iron particles. The range in tissue iron concentrations observed with these clinically widely used IICs provides an orientation as to what shou…