Chapter 5 Dosage Forms and Routes of Administration Copyright © 2011

Chapter 5 Dosage Forms and Routes of Administration Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Overview Drug names and drug sources Medication errors Dosage forms of drugs Principles of drug administration Methods of administering medications Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Drug Names Most drug entities are known by several names or designations These include the drug’s chemical, generic, and trade (or brand) names The generic name is the official name of the drug The trade or brand name is assigned by the manufacturer, and it is protected by copyright Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Drug Sources Five basic sources of drugs: – – – – – Plants Animals (including humans) Minerals or mineral products Synthetic chemicals Bio- or genetically engineered drugs Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Examples of Drugs and Their Sources Digitalis ― from the foxglove plant Table salt, iron, potassium, silver, gold ― from earth and soil sources Pancreatin, pepsin, thyroid hormone, insulin — from animal fluids, glands, and enzymes (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Examples of Drugs and Their Sources Meperidine, sulfonamides, oral contraceptives — synthetically made from artificial substances Newer forms of insulin — from gene splicing or genetic engineering Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Dosage Form of Drugs Drug dosage forms are classified according to their physical state and chemical composition They may include gases, liquids, solids, and semisolids Some substances can change from one state to another, such as solids to liquids (melting), or liquids to gaseous states (vaporization) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Solid Drugs Tablets — may be chewable, sublingual, enteric-coated, or buffered Plasters — compositions of liquid and powder that harden when they dry Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Solid Drugs Capsules — drug is contained in an external shell, usually gelatin; used when medications have unpleasant odor or taste Sustained-release (SR) or timed-release capsules — released slowly, over a period of time Caplets — shaped like capsules but consisting of tablets that are film-coated to make swallowing easier Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Solid Drugs Gelcaps — oil-based medication enclosed in soft gelatin capsules Powders — drugs dried and ground into fine particles Granules — small particles encased in a gelatin capsule Troches/lozenges — flattened disks containing medicine intended for localized mouth or throat application Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Solid Dosage Forms Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Semisolid Drugs Suppositories — bullet-shaped dosage forms inserted into a body orifice (rectum, vagina, and urethra are most common) Ointment — greasy medication for external application; usually rubbed into the skin (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Semisolid Drugs Cream — nongreasy preparations with a water base, applied to the skin or administered via an applicator (such as with intravaginal creams) Gel — jellylike substance for topical application Lotions – preparation applied to skin to treat dermatologic disorders (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Semisolid Drugs Paste – topical with a fatty base ingredient Patches – method of delivery for some semisolid dosages forms Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Liquid Drugs Syrups — consist of a high concentration of sugar in water, which may or may not have medicinal substances added Solutions — drugs dissolved in a solvent, such as normal saline Spirits — alcohol-containing liquids used as solvents; also called essences (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Liquid Drugs Elixirs — consist of water, alcohol, and sugar Tinctures — alcoholic preparations of soluble drugs Fluid extracts — concentrated solutions of a drug removed from plant sources Liniments — mixtures of drugs with oil, soap, water, or alcohol (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Liquid Drugs Mixtures and suspensions — agents mixed with a liquid but not dissolved; must be shaken before use Aromatic waters — mixtures of distilled water with an aromatic volatile oil Emulsions — pharmaceutical preparations of two agents that are not ordinarily mixed, such as oil inside water; most creams and lotions are emulsions Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Liquid Dosage Forms Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Gaseous Drugs Include anesthetic gases and compressed gases Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Principles of Drug Administration Determination factors: – Action of medication on the body – Physical and emotional state of the patient – Characteristics of the drug Other factors include: – Age of patient – Disease and condition of patient – Absorption, distribution, metabolism, and elimination of drugs Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Oral Route Safest and most convenient route Presence or absence of food in the stomach affects the absorption rate Oral drugs are usually not used when the patient is nauseated or vomiting (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Oral Route Basic equipment needed for administration: – – – – Medicine cup Water cup Medicine dropper/oral syringe Calibrated spoon Sublingual — used when rapid action is desired, such as with migraine and angina medications Buccal — placed between cheek and gum Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Tools for Administration of Liquid Dosages Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Sublingual Administration Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Parenteral Route Administration of drugs other than through the digestive system is called parenteral because the drugs bypass the GI tract Basic equipment needed for parenteral administration includes: – – – – Needles Syringes Ampules or vials Solutions, powders, and others Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Needles Two types available: disposable (most common) and nondisposable Needle gauge is determined by the diameter of the lumen or opening at the beveled tip Range from 13 to 31 in gauge size, with lengths between 3/8 inch and 2 inches The larger the gauge, the smaller the diameter of its lumen (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Needles Needles consist of 5 parts: – – – – – Point Lumen Shaft Hub Hilt Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Parts of a Syringe Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Syringes Disposable syringes are sterilized, prepackaged, nontoxic, nonpyrogenic, and ready for use Syringe sizes range from 0.5 to 50 cc Most frequently used sizes are 1, 3, and 5 cc syringes Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Types of Syringes Hypodermic — typically used for intramuscular or subcutaneous injections Retractable needle cover — used to prevent needle sticks; includes the injector pen used for insulin administration Insulin — calibrated in units (U) specifically for diabetes use; sizes are 0.5 and 1 cc (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Types of Syringes Tuberculin — used for small injections made intradermally; also used in allergy testing Prefilled — come with a single dose of medication already inside; for one-time use Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Medication Containers Ampules — small sealed glass containers usually holding a single dose Vials — small bottles with rubber stoppers through which a sterile needle is inserted for the withdrawal of a dose of medication; some are for multiple uses Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Ampules and Vials Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Parenteral Medication Forms Parenteral refers to injection of liquid substances into the body via a sterile needle and sterile syringe Can be liquid or powder (reconstituted to a liquid) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Parenteral Routes Muscles (intramuscular) Veins (intravenous) Skin (intradermal or subcutaneous) Spinal column Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intradermal (ID) Injections Given within the skin If correctly done, a small wheal occurs on the skin A three-eighths inch or 27- or 28-gauge needle is used Angle of insertion is 15 degrees, almost parallel to the skin surface (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intradermal (ID) Injections Common site of injection is the forearm Upper chest and back are also used Skin tests for allergies and tuberculosis are commonly done with this method Mantoux test is the preferred test for tuberculosis Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intradermal Injection Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Subcutaneous (SC) Injections Given just below the skin in layer of fatty tissue called adipose tissue Commonly given in deltoid, anterior thigh, abdomen, and upper back Angle of insertion is 45 degrees, except for insulin and heparin, which are at 90 degrees Amount of drug should not exceed 2 cc Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Subcutaneous Injection Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intramuscular (IM) Injections Preferred sites are the gluteus, deltoid, and vastus lateralis (thigh) muscles in adults Used for drugs that require more rapid absorption or large volumes of medication The vastus lateralis is usually used in infants Angle of insertion is 90 degrees Dosage may be from 0.5 to 5 ml (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intramuscular (IM) Injections Infants and children should be given no more than 2 ml Needle should be 1 to 3 inches in length, and even longer for obese patients Recommended gauge ranges from 20 to 23 Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intramuscular Injection Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Z-Track Intramuscular Injections Used when the drug is irritating to skin tissue Displaces upper tissue laterally before the needle is inserted Injection site should not be massaged after injection Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Intravenous (IV) Injections Used during emergency situations Rate of absorption and onset of action are faster with this method Usually inserted into superficial veins Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Pump Systems Pumps provide continuous flow into the system Are electronic devices that force precisely measured amounts of fluid into veins over time Often used for diabetic patients Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Topical Route Applied to body surface Most are designed for local use Examples of topical medications are: – – – – Lotions Liniments Ointments Transdermal patches Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Transdermal Patches Absorbed slowly through the skin Drug is carried from skin by capillaries Examples include: – – – – – Nitroglycerin Estrogen Testosterone Nicotine Scopolamine Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Inhalation Administration The act of drawing breath, vapor, or gas into the lungs is called inhalation Medication is inhaled to achieve local effects within the respiratory tract Oxygen therapy, ordered as liters per minute (LPM), with a percentage of oxygen concentration (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Inhalation Administration Medications that utilize inhalers include: – Bronchodilators – Mucolytic agents – Steroids (continues) Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Inhalation Administration A high concentration of inhaled oxygen in newborns causes: – – – – Alveolar collapse Intra-alveolar hemorrhage Hyaline membrane formation Retrolental fibroplasias Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Spray and Aerosol Liquids or fine powders sprayed in a fine mist Respiratory treatment for asthma and skin sprays are most common Most are liquids, but some are powders with very small particles that pass through the spray apparatus Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Ophthalmic Administration Drops and ointments with local effect Must be sterile to avoid infections Must be isotonic to minimize burning Examples of ophthalmic administration are: – – – – – Antibiotics Antivirals Decongestants Artificial tears Topical anesthetics Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Ophthalmic Route Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Otic Route Medication instilled into the ear Very low doses of medications are required Contraindicated if eardrum is perforated Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Otic Route Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Nasal Route Nasal solutions act locally to treat minor congestion or infection Can be in the form of drops or sprays Commonly used for blocked nasal passages and nosebleeds Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Nasal Route Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Vaginal Route Local infections are treated using suppositories, tablets, creams, and fluid solutions Most effective if patient is lying down Creams and foams are instilled with applicators Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Rectal Route Useful if patient is nauseated, vomiting, or unconscious Usually administered after a bowel movement or enema for best effect Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Rectal Route Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Implants Insertion of medication by surgery under the skin Sometimes used for contraception in the female; effective for up to 5 years Medication slowly, consistently secretes Copyright 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.