CHAPTER 10 RECONSTITUTION OF POWDERED DRUGS 89 CHAPTER 10 Reconstitution of Powdered Drugs Objectives The learner will: 1. prepare solutions from powdered drugs using directions printed on vial labels. 2. prepare solutions from powdered drugs using drug literature or inserts. 3. determine the expiration date and time for reconstituted drugs. 4. calculate dosages for reconstituted drugs. Suggested Review Questions 1. Why are some drugs packaged in powdered form? 2. List the steps used when reconstituting a drug supplied in powdered form. 3. What information needs to be written on the drug label when the drug is a multiple strength solution? 4. Ask learners this question: You need to administer a drug supplied in powdered form; however, the type and amount of diluent needed to reconstitute the drug are not noted on the label. Where would you look for this information? Answers to Review Questions 1. Drugs that are packaged in powdered form need to be reconstituted prior to administration because they retain potency only a short time in solution. Stress the importance of reading labels to determine the amount of time a drug is stable in solution and the need to use that information when planning for drug administration. 2. The steps for reconstituting a drug supplied in powdered form are a. Determine the type and volume of diluent needed. b. Choose the appropriate sterile syringe to use when drawing up the diluent and injecting it into the medication vial. c. Use aseptic technique to draw up the specified amount of diluent and inject it into the medication vial.
90 SECTION 3 READING MEDICATION LABELS AND SYRINGE CALIBRATIONS d. Roll the vial in your hands to dissolve all the powder (emphasize not to shake the vial). e. Label vial with your initials (the person who did the reconstitution) and the expiration date and time. f. Store reconstituted medication according to label directions. 3. The essential information that needs to be written on the label of a multiple solution drug is the initials of the individual who reconstituted the drug, the dosage strength of the mixture, and the expiration date and time. 4. When not noted on the drug label, the preparation and stability information for a particular drug can be found on the package insert.
CHAPTER 10 RECONSTITUTION OF POWDERED DRUGS 91 Name Date Chapter 10: Reconstitution of Powdered Drugs Additional Practice Problems Refer to the medication labels below and determine the amount and type of diluent needed to reconstitute the drug, the amount of reconstituted drug needed to deliver the ordered dose (calculate to nearest 10th), the correct method for storage of the reconstituted drug, and the length of time the reconstituted drug will retain potency. 1. a. Dose: Solu-Medrol 250 mg b. Type of diluent c. Amount of diluent d. Storage method e. Will retain potency Used with permission from Pfizer Inc. f. Other special instructions 2. a. Dose: cytarabine 150 mg b. Type of diluent c. Amount of diluent d. Storage method e. Will retain potency Used with permission from Bedford Laboratories, A Division of Ben Venue Laboratories Inc. A Boehringer-Ingelheim Company. 3. Nafcillin 500 mg has been ordered. Nafcillin is supplied as a powder in a vial. The directions on the vial label state reconstitute with 6.6 ml of normal saline. Each ml will contain 250 mg of nafcillin. 2010 Cengage Learning. All Rights Reserved. Permission to reproduce granted for classroom use only.
92 SECTION 3 READING MEDICATION LABELS AND SYRINGE CALIBRATIONS 4. Cefazolin 500 mg is ordered. Cefazolin is supplied as a powder in a vial. Directions on the vial state add 10 ml of sterile water for injection for a concentration of 100 mg/ml. 5. Ticarcillin 700 mg is ordered. Ticarcillin is supplied as a powder in a vial. Directions on the vial state add 2 ml of sterile water for injection. Each 2.6 ml of solution will contain 1 gram of ticarcillin. 6. Penicillin Potassium V 125 mg oral suspension is ordered. Penicillin Potassium V is supplied as a powder in a screw-top bottle. Directions on the bottle state fill with 75 ml of water and shake to mix completely. Each 5 ml of solution contains 250 mg of Penicillin Potassium V. 7. Levothyroxine 100 mcg has been ordered. The vial of levothyroxine states reconstitute with 5 ml of 0.9% sodium chloride injection. Once reconstituted, the concentration of levothyroxine is 40 mcg/ml. 8. Voriconazole 150 mg is ordered. Voriconazole is supplied as a powder in a vial. Directions on the label state reconstitute with 19 ml of sterile water for injection to obtain a solution containing 10 mg/ml. 9. 250 mg Vantin oral suspension is ordered. Vantin is supplied as a powder in a screw-top bottle. Directions on the label state add 29 ml water and shake to mix thoroughly. Once reconstituted, each 5 ml will contain 100 mg of Vantin. 10. Zithromax 200 mg has been ordered. Zithromax is supplied as a powder in a vial. Directions on the vial state reconstitute with 4.8 ml of sterile water for injection. Each ml of solution contains 100 mg of drug. 2010 Cengage Learning. All Rights Reserved. Permission to reproduce granted for classroom use only.
CHAPTER 10 RECONSTITUTION OF POWDERED DRUGS 93 Solutions to Additional Practice Problems 1. a. 4 ml: When reconstituted, there is 500 mg in 8 ml; 250 mg is needed which is half of total mg, thus half of total volume. b. bacteriostatic water for injection c. 8 ml d. controlled room temperature 20 to 25 C; 68 to 77 F e. 48 hours after reconstitution f. protect from light 2. a. 3 ml: Label states that once reconstituted, each ml contains 50 mg of medication. Therefore, if there is 50 mg in 1 ml, 3 ml are needed for 150 mg. b. bacteriostatic water for injection c. 10 ml d. controlled room tempurature 15 to 30 C; 59 to 86 F e. 48 hours 3. 2 ml is needed. 500 mg is ordered. There is 250 mg per ml, therefore, 2 ml is needed. 4. 5 ml is needed. 500 mg is ordered, and the concentration of drug is 100 mg/ml. A fraction depicting the ratio needed given what is supplied can be formed: 500 mg/ 100 mg/ml = 5 ml. 5. 1.8 ml is needed. 700 mg is ordered, and the concentration of drug is 1 g or 1000 mg/ 2.6 ml. A fraction depicting the ratio needed given what is supplied can be formed: 700 mg/1000 mg/ml = 0.7 ml = total volume needed. To solve for volume multiply 0.7 2.6 = 1.82 = 1.8 ml when rounded to nearest tenth. 6. 2.5 ml is needed. 125 mg is ordered, and the concentration of drug is 250 mg/5ml. 125 mg is half of 250 mg, therefore, half of 5 ml is 2.5 ml. 7. 2.5 ml is needed. 100 mcg is ordered, and the concentration of drug is 40 mcg/ml. A fraction depicting the ratio needed given what is supplied can be formed: 100 mcg/ 40 mcg/ml = 2.5 ml.
94 SECTION 3 READING MEDICATION LABELS AND SYRINGE CALIBRATIONS 8. 15 ml is needed. 150 mg is ordered, and the concentration of drug is 10 mg/ml. A fraction depicting the ratio needed given what is supplied can be formed: 150 mg/ 10 mg/ml = 15 ml. 9. 12.5 ml is needed. 250 mg is ordered, and the concentration of drug is 100 mg/5 ml or each ml would contain 20 mg. A fraction depicting the ratio needed given what is supplied can be formed: 250 mg/20 mg/ml = 12.5 ml. 10. 2 ml is needed. 200 mg is ordered, and the concentration of drug is 100 mg/ml. A fraction depicting the ratio needed given what is supplied can be formed: 200 mg/ 100 mg/ml = 2 ml.