Chapter 5 Dosage Forms Abbreviations and Routes of
Chapter 5 Dosage Forms, Abbreviations, and Routes of Administration Copyright © 2004 by Elsevier Inc. All rights reserved.
Introduction • For a technician to become proficient, it is necessary to interpret orders correctly • Many doctors’ handwriting is referred to as “chicken scratch” and it is the responsibility of the pharmacy to interpret and clarify orders if necessary • Many abbreviations used in prescribing medication look very much alike Copyright © 2004 by Elsevier Inc. All rights reserved.
Where Do Pharmacy Abbreviations Originate? • Terminology in pharmacy and medicine comes from the Latin and Greek languages • Because pharmacy began in Europe, most of the abbreviations have their origins in a foreign language • Latin and Greek serve as the universal language that all medical personnel can understand Copyright © 2004 by Elsevier Inc. All rights reserved.
Interpreting Doctors’ Orders • It is very important for the pharmacy staff to interpret doctors’ orders correctly • When writing out the various abbreviations, be sure to write as neatly as possible because other technicians and pharmacists will be reading your handwriting • Technicians must learn all of the dosage forms and abbreviations to decipher doctors’ orders Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Dosage Forms • A dosage form refers to the package or container of which the drug has taken the shape • For example, it may be a tablet or a capsule • There is more than one type of tablet or capsule • Tablets come in a wide variety of shapes and sizes Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Dosage Forms • Tablets can be scored or unscored and coated or uncoated • Much of what determines the dosage form of a medication is determined by the drug’s effectiveness • Manufacturers prepare certain medications with the ability to release the active ingredient over an extended period Copyright © 2004 by Elsevier Inc. All rights reserved.
A. Unscored tablet B. Scored tablet Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Dosage Forms • This allows the patient to take the medication less often, which increases compliance • Three major categories of dosage forms: – Solids – Liquids – Semisolids Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Dosage Forms • Solid agents can be contained in various packages and administered by almost all routes except parenterally • Most tablets contain fillers (inert substances–no active ingredient), sugar coatings, and certain additives Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Dosage Forms • Tablets are made to be administered sublingually (sl) or vaginally • Tablets can be scored to allow for dosage to be cut in half • Chewable tablets are convenient for persons who have difficulty swallowing and for children Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Dosage Forms • Tablets can be enteric coated (EC) to protect the drug through the acidic environment of the stomach or to delay release of the drug • Extended-release–types are made to control the amount of drug distributed over a set time Copyright © 2004 by Elsevier Inc. All rights reserved.
Plain tablets Scored tablets Copyright © 2004 by Elsevier Inc. All rights reserved. Enteric-coated tablets
Capsules and Caplets • Capsule and caplet dosage forms are closely related to tablets • Capsules can have either a hard or soft outer shell • Hard capsules are composed of sugar, gelatin, and water • Pulvule–type of capsule that is shaped differently for identification purposes Copyright © 2004 by Elsevier Inc. All rights reserved.
Capsules and Caplets • Spansules–can be pulled apart to sprinkle the medication onto food for children • The main difference between capsules and caplets is that capsules can be pulled apart Copyright © 2004 by Elsevier Inc. All rights reserved.
Types of Capsules Extended-release capsules Copyright © 2004 by Elsevier Inc. All rights reserved.
Lozenges/Troches • These are other forms of tablets that are not meant to be swallowed but to dissolve in the mouth, which releases the medication more slowly; similar to hard candy • Cough drops • Troches are larger than normal-sized tablets and are flat; chalky consistency Copyright © 2004 by Elsevier Inc. All rights reserved.
Implants • A special type of capsule can be implanted under the skin and left in place for up to 5 years • Contraceptives containing progestin • Medication is released in a stair-step method Copyright © 2004 by Elsevier Inc. All rights reserved.
Patches • Solid pieces of material that hold a specific amount of medication to be released into the skin over time • Easily administered and eliminate a possible upset stomach • Uses: Angina-Nitroglycerin; chronic pain- Duragesic • Motion sickness-Scopolamine Copyright © 2004 by Elsevier Inc. All rights reserved.
Liquids • Composed of various solutions • Can be administered by all routes • Syrups–sugar-based solutions that have medications dissolved in them, which improves the taste of the drug. They tend to be thicker than water Copyright © 2004 by Elsevier Inc. All rights reserved.
Liquids • Elixirs–agents that contain dissolved medication in either an alcohol base or water and alcohol (hydroalcoholic) base • Alcohol usually covers up the bad taste of the drug • Elixirs have the same consistency as water Copyright © 2004 by Elsevier Inc. All rights reserved.
Sprays • Sprays are composed of various bases as alcohol or water in a pump-type dispenser • Nasal decongestants or sunscreens • Nitroglycerin translingual spray that is used under the tongue for relief of anginal pain Copyright © 2004 by Elsevier Inc. All rights reserved.
Inhalants and Aerosols • Inhaler agents come in a variety of forms but all must be easily inhaled into the lungs • Common devices available OTC are vaporizers and humidifiers • Respiratory therapists use nebulizers to give breathing treatments to hospital patients • Patients can also be trained to use nebulizers at home Copyright © 2004 by Elsevier Inc. All rights reserved.
Inhalants and Aerosols • Anesthetics come in solutions that are inhaled and administered during surgery by an anesthesiologist • Prescribed inhalants contain drugs that treat asthma and allergies • Metered dose inhalers (MDIs) dispense a specific amount of drug with each puff or inhalation Copyright © 2004 by Elsevier Inc. All rights reserved.
Emulsions • The mixture of water and oil when used with an emulsifier binds the two together • Oil can have water as a base • Water is contained in an oil base • Most emulsions are used topically. Some are used parenterally, such as lipids (fats) in nutritional parenteral feedings Copyright © 2004 by Elsevier Inc. All rights reserved.
Suspensions • These are liquids that have very small, solid particles suspended in the base solution • They can be used orally by children and seniors • Suspensions have a “shake well” sticker and a date of expiration Copyright © 2004 by Elsevier Inc. All rights reserved.
Enemas • Enemas may be administered for two different reasons–retention or evacuation • They can be used to deliver medication to the body, bypassing the stomach while being absorbed • Most common use is to evacuate the lower intestine to prepare for surgeries or for women in labor Copyright © 2004 by Elsevier Inc. All rights reserved.
Semisolids • Semisolids contain both liquids and solids • They are meant for topical application • Creams–have medications in a base that is part oil and part water and for topical use • Lotions are thinner than creams because their base contains more water Copyright © 2004 by Elsevier Inc. All rights reserved.
Semisolids • Ointments contain medication in a glycol or oil base; they cover the skin surface and keep out moisture • Gels contain medication in a very viscous (thick) liquid that easily penetrates the skin • Pastes contain a lesser amount of liquid base than solids. They are able to absorb skin secretions unlike other topical agents Copyright © 2004 by Elsevier Inc. All rights reserved.
Suppositories • Can be used both rectally and vaginally • Rectal suppositories bypass the stomach, which is important if the patient has nausea and vomiting • Vaginal suppositories are used mainly to treat vaginal infections Copyright © 2004 by Elsevier Inc. All rights reserved.
Powders • Powders are solids, yet they can be packaged in some forms that allow them to be sprayed similar to liquid dosage forms • One of the main uses is to decrease the amount of wetness of an area • Antifungal foot agents • They can also be spread over a wide area Copyright © 2004 by Elsevier Inc. All rights reserved.
Routes of Administration • By mouth or oral medications are very convenient, do not need to be measured, less expensive, systemic, and safe • The downside is that they do not work as quickly as parenterals • Some drugs cannot be taken orally because they are not as effective Copyright © 2004 by Elsevier Inc. All rights reserved.
Sublingual and Buccal Agents • Nitroglycerin is the most commonly used sublingual tablet that treats anginal attacks • Buccal agents are placed between the gum and cheek where the medication penetrates the mouth lining and then enters the bloodstream Copyright © 2004 by Elsevier Inc. All rights reserved.
Rectal • Rectal (R) agents are used in a person who is vomiting and cannot take oral medications • To reduce inflammation, either ointments or creams can be used in addition to suppositories • They work on a specific site and not systemically • Downside–they are uncomfortable and the actual amount of drug absorbed is unpredictable Copyright © 2004 by Elsevier Inc. All rights reserved.
Capsule Sizes • Capsules vary in size, color, transparency, and identifying marks • The larger half of the capsule is known as the body and the smaller half is known as the cap • Not all capsules are meant to be swallowed; specific dosages of medications can be sprinkled onto food or into liquids Copyright © 2004 by Elsevier Inc. All rights reserved.
Topical • Topical (TOP) preparations effects range from systemic to localized for rashes • There agents to fight skin infections, inflammation, and UV rays of the sun • They work at the site of action and systemically • An advantage is easy application • A downside is that they may cause a reaction Copyright © 2004 by Elsevier Inc. All rights reserved.
Parenteral: Intravenous, Intravenous Piggyback, Intramuscular, Subcutaneous • Parenteral comes from the Greek and means “side of intestine” or “outside of intestine” • The most common parenteral medications are given IV, IM, or SC • Very small gauge needles are used, and the length depend on the site being injected • Benefits–speed of action Copyright © 2004 by Elsevier Inc. All rights reserved.
Parenteral: Intravenous, Intravenous Piggyback, Intramuscular, Subcutaneous • Parenteral drugs work within a few minutes • Important for emergency situations, for those who are combative, or for those who are unable to swallow • A disadvantage is the increased risk of infection Copyright © 2004 by Elsevier Inc. All rights reserved.
Parenteral: Intravenous, Intravenous Piggyback, Intramuscular, Subcutaneous • Injections are more expensive and require preparation and administration by trained personnel • Another downside is that once a drug is injected there is little time to alter its course if an allergic reaction takes place or too much drug is given Copyright © 2004 by Elsevier Inc. All rights reserved.
Eye, Ear, Nose • Doctors often use eye solutions to treat ear conditions, but ear solutions cannot be used to treat eye conditions because the eye is sterile • All eye agents are sterile • Otic preparations are not necessarily sterile because they treat the ear canal and do not penetrate a sterile environment Copyright © 2004 by Elsevier Inc. All rights reserved.
Eye, Ear, Nose • All ophthalmics need to be kept sterile • For the eye, ear, and nose there are different types of agents, including ointments, solutions, and suspensions • Most ear treatments are for clearing up infections or cleaning out ear wax buildup Copyright © 2004 by Elsevier Inc. All rights reserved.
Eye, Ear, Nose • Most nasal sprays are used to treat colds and allergies • Eye treatments are for infections, inflammation, and glaucoma • These dosage forms work on the specific site rather than the whole body Copyright © 2004 by Elsevier Inc. All rights reserved.
Eye, Ear, Nose • A main disadvantage of solutions for the eye, if not kept sterile, is that they can introduce bacteria into the area being treated • Ophthalmics do not last as long as other treatments because of the blinking of the eye and tearing • Ointments make it hard to see clearly Copyright © 2004 by Elsevier Inc. All rights reserved.
Inhalants • Inhalants (INH) are used to treat lung diseases • Dosage forms are limited but very effective if used properly • MDIs are used for asthma, bronchitis, or emphysema • Corticosteroids are also available in MDIs for more chronic conditions Copyright © 2004 by Elsevier Inc. All rights reserved.
Inhalants • Onset of action is very quick • Most aerosols come in handheld units and are very convenient • The downside is that, if not used properly, little if any of the drug is able to get into the lungs Copyright © 2004 by Elsevier Inc. All rights reserved.
Miscellaneous Routes • Vaginal or uretheral dosage forms– suppositories, ointments, foams, and gels • They are used for treatments of infections and inflammation; vaginal foams are used as a contraceptive • Advantages are they bypass a systemic effect and affect a specific site but are not easily applied and are uncomfortable Copyright © 2004 by Elsevier Inc. All rights reserved.
Other Considerations: Form and Function • Dosage forms are created based on the results from many clinical trials that delve into the pharmacokinetics of the medication or the function of the drug in experiments Copyright © 2004 by Elsevier Inc. All rights reserved.
Pharmacokinetics • Represent many different components concerning the actions of a drug • Considerations such as: – Levels of the drug throughout the blood and tissues – Absorption or movement of the drug throughout the body – Overall distribution Copyright © 2004 by Elsevier Inc. All rights reserved.
Pharmacokinetics • Metabolism • Excretion of the drug • Reaction of the drugs with other drugs • Patient compliance • Life of the drug that includes bioavailability, half-life, bioequivalence, and excretion Copyright © 2004 by Elsevier Inc. All rights reserved.
Absorption • Medications are made to get through natural body barriers, such as the skin, stomach, intestines, blood-brain barrier, and other membranous tissues • How well the drug passes through these barriers is the one factor that determines its ultimate effectiveness Copyright © 2004 by Elsevier Inc. All rights reserved.
Absorption • Important chemicals and drugs are able to pass a lock and key mechanism by latching onto receptor sites that allow the chemical or drug to pass into the organ to reach the final site of action intended for the drug Copyright © 2004 by Elsevier Inc. All rights reserved.
Distribution • After the absorption of a medication, it is distributed throughout the body from the bloodstream into tissues, membranes, and ultimately organs of the body • The distribution of a drug throughout the body is not necessarily equal throughout the whole body Copyright © 2004 by Elsevier Inc. All rights reserved.
Metabolism • Most metabolism takes place in the liver • Metabolism changes the chemical structure of the original drug • There are different influences that can alter metabolism such as age, gender, genetics, diet, and other chemicals digested Copyright © 2004 by Elsevier Inc. All rights reserved.
Excretion • Excretion is the last phase of a drug’s life in the body • There are many ways a drug can be excreted from the body: via the kidneys, feces, exhalation, sweat glands, breast milk • Urination and bowel movements are the most common methods of excretion Copyright © 2004 by Elsevier Inc. All rights reserved.
Bioavailability • This is the rate at which the drug makes it to its destination and is available to the site of action for which it was intended • Many drugs travel into the liver before they have a chance to be absorbed into the whole system. • Known as the “first pass effect” Copyright © 2004 by Elsevier Inc. All rights reserved.
Half-Life • Refers to the measurement of the time it takes the body to break down and excrete one half of the drug • This is an important factor in the creation of drugs for it tells the manufacturer how long it takes the body to rid itself of the drug Copyright © 2004 by Elsevier Inc. All rights reserved.
Bioequivalence • This is the comparison between drugs either from different manufacturers or in the same company but from different batches of a drug • Generic drug manufacturers strive to achieve the same equivalence as brand name manufacturers for competition Copyright © 2004 by Elsevier Inc. All rights reserved.
The Use of Additives • All medications are prepared with some sort of additive • These include coloring, flavorings, fillers, and preservatives • Other types include those that increase the dispersing of the drug once it reaches the intestines and others that release the medication over a longer period of time Copyright © 2004 by Elsevier Inc. All rights reserved.
Manufactured Products • All types of dosage forms must be made and approved by the Food and Drug Administration (FDA) Copyright © 2004 by Elsevier Inc. All rights reserved.
Large-volume IV IVPB Copyright © 2004 by Elsevier Inc. All rights reserved.
Miscellaneous Agents and Devices • Ocular inserts–lenses inserted into the eye that release a continuous amount of drug over time • Injectable Forms–long-acting for birth control, antipsychotic episodes, and steroids Copyright © 2004 by Elsevier Inc. All rights reserved.
Packaging and Storage Requirements • Medications are packaged according to manufacturers’ specifications to ensure effectiveness and shelf life of the drug • All medications have a package insert that describes the storage and stability of the drug Copyright © 2004 by Elsevier Inc. All rights reserved.
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