View clinical trials related to Pharmacokinetics.
Filter by:Intravenous (IV) morphine requirement for immediate postoperative pain control depends upon the complex interplay of patient history, wound severity, environment, and genetics. Even for relatively uniform stimulus intensity, such as that associated with tonsillectomy and adenoidectomy (T&A), there can be marked individual variability in response to morphine. Some patients are refractory to standard doses and need increased amounts. Others are sensitive, require less drug to attain acceptable pain levels, and/or experience unwanted side effects that limit dosing. A significant number must be switched to different analgesics altogether. Despite the long clinical history of morphine as a postoperative analgesic, researchers have only begun to examine the origins of response variability. The investigators will look at 2000 retrospective Tonsillectomy and Adenoidectomy (T&A) cases and using this data and incorporating additional patient, surgical, and environmental factors that may contribute to response variability, the investigators then propose a prospective genome-wide association (GWA) study of 1500 children ages 4 to 18 years treated with IV morphine sulfate for day surgery T&A.
The purpose of this study was to compare the pharmacokinetic profiles at steady-state of the test product, Tramadol HCl Once-A-Day (OAD) 200 mg tablets and the reference product, Tramadol HCl 50 mg (IR) tablets (Ortho-McNeil Ultram®). For this purpose, the extent of absorption of tramadol and formation of O-desmethyltramadol (measures of systemic exposure) after multiple administration of 50 mg 6-hourly at 07:30, 13:30, 19:30 and 01:30 (reference product) and 200 mg 24-hourly at 07:30 (test product), were compared.
The purpose of this study is to evaluate the relative drug concentrations achieved with different formulations of GSK1838262 in healthy volunteers.
TMC125 is from the class of drugs called non-nucleoside reverse transcriptase inhibitors (NNRTIs). NNRTIs work by blocking reverse transcriptase, a protein that HIV needs to make more copies of itself. TMC125 is used in the treatment of adults with HIV-1 infection. The purpose of this trial is to see if there is any potential interaction (change in the effectiveness of the drug) when taking multiple-dose TMC125 and buprenorphine/naloxone together. The trial will also assess the short-term safety and tolerability (how well your body handles the drug) when TMC125 and buprenorphine/naloxone are taken together.
The purpose of this study is to evaluate how much and how fast a single, oral, daily 25 mg dose of TMC278 is absorbed into the body when administered as a solution, suspension, granules, or a tablet. In addition, the effect of each formulation of TMC278 will be evaluated in patients in the fasted and fed states and the palatability (how the drug tastes) of each formulation will be assessed. Finally, the safety and tolerability of each formulation of TMC278 will be assessed throughout the study.
To estimate the pharmacokinetics of single doses of benzodiazepines in Mexican adult healthy volunteers: a) alprazolam tablet extended release, b) alprazolam tablet immediate release, and clonazepam tablet.
The purpose of this study is to evaluate the effects of a chronic co-medication of efavirenz on pharmacokinetics and sterol-lowering effects of ezetimibe at steady-state in healthy subjects genotyped for ABCB1, ABCC2, CYP2B6 and UGT1A1.
The aim of the investigators research is to see if variants in a particular gene (named CYP2B6) affect how the body metabolizes (breaks down) certain medications, including the drug bupropion. Bupropion is widely used in the treatment of depression and for helping people quit smoking. Genes are portions of DNA that code for particular proteins in the body. The investigators are studying the gene that codes for a protein called CYP2B6. Differences in the structure of the gene are called variants and may mean that a person metabolizes a drug faster or slower than a person with a different variant.
In a prior in vitro study using human hepatocytes quinine was shown to induce the activity of Cytochrome p450 CYP 1A2. The present study will evaluate the extent to which quinine sulfate-related induction of this enzyme effects the pharmacokinetics of theophylline, a sensitive probe drug for the activity of CYP 1A2. It will also evaluate the effect of single-dose theophylline on the pharmacokinetics of steady-state quinine sulfate.
Metformin is widely used for treatment of type 2 diabetes mellitus. Side-effects are few and mainly from the gastrointestinal tract. Since metformin is cleared from the blood exclusively via the kidneys reduced renal function is a relative contraindication. We have earlier demonstrated that metformin safely can be used to a lower GFR level of 30 ml/min/1.73. Below that level the risk of lactacidosis, a severe complication, increases. In the present study we plan to analyse serum levels of metformin repeatedly in patients with moderate renal failure (CKD = GFR of 30-60 ml/min/1.73). Blood samples will be taken as trough values in the morning, week 0, 2, 4, and 8 and at four weeks a blood sample will be taken two hours after intake of the morning dose of metformin. Renal function will be estimated with creatinine and cystatin C at each occasion. The intraindividual variation of metformin will be calculated. The study rests on a new method for measuring metformin. The technique uses Liquid Chromatography Tandem Mass Spectometry (LCMSMS). Proteins are removed from serum by adding acetonitrile to the sample. After centrifugation a diluted portion of the supernatant is injected into the LCMSMS-system. The total runtime for a sample is 6 minutes. The study will show if variation in serum levels of metformin measured in the same patient is high or low and thus give us better understanding whether a change i serum level is due to biological variation or to increased retention caused by progressive renal failure.