RT Book, Section A1 Shargel, Leon A1 Wu-Pong, Susanna A1 Yu, Andrew B.C. SR Print(0) ID 56602695 T1 Chapter 8. Multiple-Dosage Regimens T2 Applied Biopharmaceutics & Pharmacokinetics, 6e YR 2012 FD 2012 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-160393-5 LK accesspharmacy.mhmedical.com/content.aspx?aid=56602695 RD 2024/11/07 AB Earlier chapters of this book discussed single-dose drug administration. Generally, drugs are given in multiple doses to treat chronic disease such as arthritis, hypertension, etc. After single-dose drug administration, the plasma drug level rises above and then falls below the minimum effective concentration (MEC), resulting in a decline in therapeutic effect. To treat chronic disease, multiple-dosage or IV infusion regimens are used to maintain the plasma drug levels within the narrow limits of the therapeutic window (eg, plasma drug concentrations above the MEC but below the minimum toxic concentration or MTC) to achieve optimal clinical effectiveness. These drugs may include antibacterials, cardiotonics, anticonvulsants, hypoglycemics, antihypertensives, hormones, and others. Ideally, a dosage regimen is established for each drug to provide the correct plasma level without excessive fluctuation and drug accumulation outside the therapeutic window.