Pharmacology Proctored ATI Study Guide

Chapter1: Pharmacokinetics and Routes of Administration Absorption  Route of admin affects the rate and amount of absorption o Oral:  GI pH and emptying time  Presence of food in the stomach or intestines  Form of meds (liquid/XR) o Sublingual/buccal  Quick absorption systemically through highly vascular mucous membranes o Inhalation via mouth/nose  Rapid absorption through alveolar capillary networks o Intradermal, topical  Slow, gradual absorption o SQ/IM  Highly soluble meds have rapid absorption (10-30min), poorly soluble have slower absorption  Blood perfusion at site of injection affect absorption o IV  Immediate and complete Distribution o Transportation of meds to sites of action by body fluids o Plasma binding protein: meds compete for protein binding sites within bloodstream, primarily albumin. The ability of med to bind to protein can affect how much med will leave and travel to target tissues. Metabolism o Primarily occurs in the liver but can take place in the kidney o Factors that influence metabolism:  Age (infants/older adults require smaller doses)  First pass effect: liver inactivates some meds on first pass through and thus require sublingual or IV route (may need higher dose) Excretion: o Eliminated through the kidneys. o Kidney dysfunction can result in elevated levels of medications. Med Response o Maintain plasma levels between minimum effective concentration and the toxic concentration: Therapeutic index (TI) o High TI has a wide safety margin. o Low TI requires monitoring of serum levels.