Introduction to Clinical Pharmacology Chapter 3 Making Drug Dosing Safer

Multiple Check System Order entry, bar coding, and technological checks Best method: manual redundancy system and the “5 rights and 3 checks” method

Drug Label Information Need drug, form, and dosage strength on the drug label Review the MAR Trade name = brand name; generic name = official drug name Unit dose method

Use of Zero Always use a zero before decimal points in drug dosages so the dosage is not incorrectly read .25 mg could be misread as 25 mg, rather than 0.25 mg

Calculations of Drug Dosages: Systems of Measurement Nurse must be familiar with calculations of all forms of drug dosages Systems of measurement: The metric system The apothecary system Household measurements Conversion between systems Conversion within a system

Calculations of Drug Dosages: Solutions Solute is a substance dissolved in a solvent Solutions are prepared by using a solid and a liquid, or a liquid and a liquid

Calculations of Drug Dosages: Reading Drug Labels Drug labels give important information the nurse must use to obtain the correct dosage Unit dose: a method of dispensing drugs in which each capsule or tablet is packaged separately Drug labels contain two names: trade name, generic name Dosage strength: the average strength given to a patient as one dose

Calculations of Drug Dosages: Oral Dosages of Drugs Computed: physician not available, written in apothecary system and label in metric system Tablets and capsules (dose desired)/(dose in hand) = (dose administered)

Calculations of Drug Dosages: Parenteral Drug Dosage #1 Must be in liquid form before administered Available in three forms Parenteral drugs in disposable syringes or cartridges Parenteral drugs in ampules and vials Parenteral drugs in dry form

Calculations of Drug Dosages: Parenteral Drug Dosage #2 Calculating intravenous flow rates To allow IV fluid to infuse over a specified period, the IV flow rate must be determined Methods of calculating intravenous flow rates mL/hr gtt/min

Calculations of Drug Dosages: Parenteral Drug Dosage #3 Oral or parenteral drug dosages based on weight The dosage may be based on the patient’s weight In many instances, references give the dosage based on the weight in kilograms rather than pounds

Dosage Calculations Using Dimensional Analysis: Temperatures Two scales used: Fahrenheit Celsius