Practice Problems # 15Identify the following for each of the medication labels. The answers are on pages 29-31 of the dosage calculation packet.a. Brand nameb. Generic name c. Route of administration or form d. Dosage1. Rev 05/31/09200 mgStore at controlled room temperatureNDC 0108-5012-20 Dispense in a tight, light resistant container.TagametDosage: See accompanying prescribinginformation.Cimetidine tabletsImportant: Use safety closures when Dispensing this product unless otherwise directed by physician or requested by purchaser.100 tabletsCaution: Federal law prohibits Dispensing without prescription.SmithKline Beecham Pharmaceuticals
132.CALCULATION OF ORAL DOSAGESOral dosage forms of medications include tablets, capsules, suspensions, lozenges, powders, emulsions, solutions, tinctures, syrups and elixirs. The liquid forms of oral medications are generally calculated to be administered in millimeters, cubic centimeters teaspoons, tablespoons and sometimes minims.To calculate oral dosages you will use the previously discussed method of ratio and proportion. Set the problems up just as you did in Unit II. To obtain credit for dosage calculation questions, you must correctly label the answer.Example: ORDERED: Amoxicillin 500 mg p.o.AVAILABLE: Amoxicillin 250 mg tabletsHow many tablets will the nurse administer?250 mg : 1 tablet :: 500 mg : X tablets250 X = 500X = 500X = 2 tablets250Check your answer: 250 mg: 1 tab:: 500 mg : 2 tab250 x 2 = 5001 x 500 = 500Example: ORDERED: Pentobarbital sodium 30 mg p.o.AVAILABLE: Pentobarbital sodium scoredtablets gr. IHow many tablets will the nurse administer?Rev 05/31/095 mg/mLStore below 86 F. Do not freeze.NDC 0007-3343-01Protect from light. Discard if discolored.CompazineDosage: For deep IM or IV injection. See accompanying prescribing information.Prochlorperazine Caution: Federal law prohibits Dispensing without prescription.SmithKline Beecham Pharmaceuticals
14Since the ordered form of the medication and the available form of the medication are values from different systems of measurement, you must first change the ordered form of the medication to the available form of the medication. Thistype of a problem is alwaysgoing to require 2 steps.Step 1:(The known ratio is 60 mg = 1 grain)60 mg: 1 grain :: 30 mg : X grain60 X = 30X = 30X = 1grain or 0.5 grain60 2 Step 2:Now put this answer into an equation and determine how many tablets you should administer. 1 grain: 1 tablet:: 0.5 grain : X tabletX = 0.5 ½ of a tablet.NOTE:When calculating oral doses, it is important to differentiate between the dosage calculation (math calculation) and the amount of oral medication to be administered. Example: If the dosage calculation equals 1.44 tablets or 1.4 tablets, the nurse must recognize that this amount can not be given safely to a patient. She will administer 1 ½ tablets since scored tablets may only be divided in two. The same is true regarding oral solutions. If the dosage calculation equals 4.94 mLs, the nurse will pour 5 mLs of oral solution into a calibrated medication cup.CALCULATION OF PARENTERAL DOSAGESParenteral means injection of drugs into the tissue or fluids of the body.