Chapter 29 Medications

Drug Nomenclature Chemical name — identifies drug’s atomic and molecular structure Generic name — assigned by the manufacturer that first develops the drug Official name — name by which it is identified in official publications USP and NF Trade name — brand name copyrighted by the company that sells the drug

Drug Preparations Oral Capsule, pill, tablet, extended release, elixir, suspension, syrup Topical Liniment, lotion, ointment, suppository, transdermal patch Injectable

Drug Classifications Body system Symptoms relieved Clinical indication

Mechanisms of Drug Actions Drug-receptor interaction — drug interacts with one of more cellular structures to alter cell function Drug-enzyme interaction — combines with enzymes to achieve desired effect Acting on cell membrane or altering cellular environment

Pharmacokinetics Absorption — drug is transferred from site of entry into bloodstream Distribution — drug is distributed throughout the body Metabolism — drug is broken down into an inactive form Excretion — drug is excreted from the body

Factors Affecting Drug Absorption Route of administration Drug solubility pH Local conditions at site of administration Drug dosage Serum drug levels

Adverse Effect of Medications Iatrogenic disease Allergic effects Toxic effects Idiosyncratic effects Drug interactions

Signs and Symptoms of Drug Allergy Rash Uticaria Fever Diarrhea Nausea Vomiting Anaphylactic reaction

Variables Influencing Effect of Medications Developmental considerations Weight Sex Genetic and cultural factors Psychological factors Pathology Environment, timing of administration

Types of Medication Orders Standing order — carried out until cancelled by another order Prn order — as needed Stat order — carried out immediately

Parts of the Medication Order Patient’s name Date and time order is written Name of drug to be administered Dosage of drug Route by which drug is to be administered Frequency of administration of the drug Signature of person writing the order

Medication Supply Systems Stock supply Individual supply Medication cart Computerized medication system Bar coded medication cart

Systems of Measurement Metric — meter (linear), liter (volume), gram (weight) Apothecary — less convenient and concise; basic unit or weight is grain Household — least accurate system; teaspoons, tablespoons, teacup and glass used

Metric System Conversions To convert larger unit to smaller unit, move decimal point to right. To convert smaller unit to larger unit, move decimal point to left. 1 kilogram = 1000 grams 1 gram = 1000 milligrams 1 milligram = 1000 micrograms

Three Checks of Medication Administration Read the label: When the nurse reaches for the container or unit dose package Immediately before pouring or opening medication When replacing the container to the drawer or shelf

Five Rights of Medication Administration The nurse should give: The right medication To the right person In the right dosage Through the right route At the right time

Controlled Substances Required Information Name of patient receiving narcotic Amount of narcotic used The hour narcotic was given The name of physician prescribing narcotic Name of the nurse administering narcotic

Oral Medications Solid form — tablets, capsules, pills Liquid form — elixirs, spirits, suspensions, syrups

Administration of Oral Medications Oral Route — having patient swallow drug Enteral route — administering drug through an enteral tube Sublingual administration — placing drug under tongue Buccal administration — placing drug between tongue and cheek

Administration of Parenteral Medications Subcutaneous injection — subcutaneous tissue Intramuscular injection — muscle tissue Intradermal injection — corium (under epidermis) Intravenous injection — vein Intraarterial injection — artery Intracardial injection — heart tissue Intraperitoneal injection — peritoneal cavity Intraspinal injection — spinal canal Intraosseous injection — bone

Sites for Intramuscular Injections Ventrogluteal site Vastus lateralis site Deltoid muscle site Dorsogluteal site

Criteria for Choosing Equipment for Injections Route of administration Viscosity of the solution Quantity to be administered Body size Type of medication

Preparing Medications for Injection Ampules Vials Prefilled cartridges

Topical Administration of Medications Vaginal Rectal Inunction Instillation Irrigation Skin application

Medical Record Documentation Each dose of medication, give as soon as possible after it is given Intentional or inadvertent omitted drugs Refused drugs Medication errors

Type of Medication Errors Inappropriate prescribing of the drug Extra, omitted, or wrong doses Administration of drug to wrong patient Administration of drug by wrong route or rate Failure to give medication within prescribed time Incorrect preparation of a drug Improper technique when administering drug Giving a drug that has deteriorated

Medication Errors Check patient’s condition immediately; observe for adverse effects. Notify nurse manager and physician. Write description of error on medical record and remedial steps taken. Complete special form for reporting errors.

Patient Teaching Review techniques of medication administration. Remind patient to take the medication as prescribed for as long as prescribed. Instruct patient not to alter dosages without consulting physician. Caution patient not to share medications.