therapeutic drug monitoring


Also found in: Dictionary, Thesaurus, Legal, Financial, Acronyms, Encyclopedia, Wikipedia.

therapeutic drug monitoring

Clinical pharmacology The regular measurement of serum levels of drugs requiring close 'titration' of doses in order to ensure that there are sufficient levels in the blood to be therapeutically effective, while avoiding potentially toxic excess; drug concentration in vivo is a function of multiple factors Common TDM drugs Carbamazepine, digoxin, gentamycin, procainamide, phenobarbital, phenytoin, theophylline, tobramycin, valproic acid, vancomycin
Therapeutic drug levels in vivo–factors involved
Patient compliance  Ingestion of drug in the doses prescribed
Bioavailability Access to circulation, interaction with cognate receptor(s); ionized and 'free', or bound to a carrier molecule, often albumin
Pharmacokinetics Drug equilibrium requires 4-6 half-lives of drug clearance (a period of time for1/2 of the drug to 'clear', either through metabolism or excretion, multiplied by 4-6); the drug is affected by
Interaction with foods or other drugs at the site of absorption, eg tetracycline binding to cations or chelation with binding resins, eg bile acid-binding cholestyramine that also sequesters warfarin, thyroxine and digitoxin or interactions of various drugs with each other, eg digitalis with quinidine resulting in a 3-fold ↓ in digitalis clearance
Absorption may be changed by GI hypermotility or large molecule size
Lipid solubility, which affects the volume of distribution; highly lipid-soluble substances have high affinity for adipose tissue and a low tendency to remain in the vascular compartment, see Volume of distribution.
Biotransformation, with 'first pass' elimination by hepatic metabolism, in which polar groups are introduced into relatively insoluble molecules by oxidation, reduction or hydrolysis; for elimination, lipid-soluble drugs require the 'solubility' steps of glucuronidation or sulfatation in the liver; water-soluble molecules are eliminated directly via the kidneys, weak acidic drugs are eliminated by active tubular secretion that may be altered by therapy with methotrexate, penicillin, probenecid, salicylates, phenylbutazone and thiazide diuretics
First order kinetics Drug elimination is proportional to its concentration
Zero order kinetics Drug elimination is independent of the drug's concentration
Physiological factors
Age Lower doses are required in both infants and the elderly, in the former because the metabolic machinery is not fully operational, in the latter because the machinery is decaying, with ↓ cardiac and renal function, enzyme activity, density of receptors on the cell surfaces and ↓ albumin, the major drug transporting molecule
Enzyme induction, which is involved in a drug's metabolism may reduce the drug's activity; enzyme-inducing drugs include barbiturates, carbamazepine, glutethimide, phenytoin, primidone, rifampicin
Enzyme inhibition, which is involved in drug metabolism, resulting in ↑ drug activity, prolonging the action of various drugs, including chloramphenicol, cimetidine, disulfiram (Antabuse), isoniazid, methyldopa, metronidazole, phenylbutazone and sulfonamides
Genetic factors play an as yet poorly defined role in therapeutic drug monitoring, as is the case of the poor ability of some racial groups to acetylate drugs
Concomitant disease, ie whether there are underlying conditions that may affect drug distribution or metabolism, eg renal disease with ↓ clearance and ↑ drug levels, or hepatic disease, in which there is ↓ albumin production and ↓ enzyme activity resulting in a functional ↑ in drug levels, due to ↓ availability of drug-carrying proteins

ther·a·peu·tic drug mon·i·tor·ing

(TDM) (thār'ă-pyū'tik drŭg mon'i-tŏr-ing)
Clinical measurement of the effects of a drug in a specific patient rather than reliance on normative ranges (e.g., some old people need a lower dosage than their weight might suggest). Such procedures verify that therapy is as accurate as possible.
References in periodicals archive ?
HPLC assay with ultraviolet detection for therapeutic drug monitoring of sirolimus.
Food and Drug Administration (FDA) and is designed for routine clinical chemistry applications, including drugs-of-abuse testing and therapeutic drug monitoring.
This new 249-page report provides a comprehensive analysis of the US therapeutic drug monitoring market, including emerging tests, technologies, instrumentation, sales forecasts, market shares, and strategic profiles of leading suppliers.
What's the solution to all this therapeutic drug monitoring confusion?
efficacy and helping physicians with therapeutic drug monitoring (TDM) of patients for the therapeutic agent, Methotrexate.
Benefits of this report - Up-to-date one-stop information on therapeutic drug monitoring - Description of 27 companies involved with their collaborations in this area - Market analysis 2014-2024 - Market values in major regions - Strategies for developing markets for therapeutic drug monitoring - A selected bibliography of 180 publications - Text is supplemented by 17 tables and 6 figuresKey Topics Covered: Executive Summary 1.
Frank Sedor, PhD, DABCC, FACB, is administrative director of the core, blood gas, and clinical pediatric laboratories as well as director for clinical chemistry, therapeutic drug monitoring, and toxicology services at Duke University Medical Center (Durham, NC).
Therapeutic drug monitoring has undergone a similarly impressive transformation over the past decade.
Important topics such as quantification of diagnostic and prognostic biomarkers, genomics for determining the appropriate therapy for particular patients and the role of therapeutic drug monitoring in chemotherapy management are discussed by international experts in this special focus issue of Bioanalysis.
Millennium Laboratories, a leading provider of therapeutic drug monitoring and education to physicians and staff treating chronic pain, announced today that CEO James Slattery has been appointed Chairman of the Florida PDMP Foundation, Inc.
Benefits of this report - Up-to-date one-stop information on therapeutic drug monitoring - Description of 27 companies involved with their collaborations in this area - Market analysis 2014-2024/ - Market values in major regions - Strategies for developing markets for therapeutic drug monitoring - A selected bibliography of 180 publications - Text is supplemented by 17 tables and 6 figures Who should read this report?

Full browser ?