Chapter 11 • Calculate doses of antibiotic medications measured in units • Calculate insulin doses measured in units • Calculate anticoagulant doses measured in units • Calculate medications measured in milliequivalents • Interpret dosage when the medication is expressed as a percentage • Interpret dosage of solutions expressed in ratio strength • Calculate weight of active ingredients expressed in percentage or ratio and proportion Pretest What measureable volume of medication should be given to the patient? ____________________ What type of syringe should be used to administer this medication? ____________________ Interpret the physician’s order. ______________________________________________________ Interpret the medication order. ______________________________________________________ What is the measurable volume of medication that should be given to the patient? ____________________ What type and size of syringe should be used to prepare this medication? ____________________ What is the total volume of medication in the vial? ____________________ What is the total strength of heparin in the vial? ____________________ What volume of medication should be given to the teen? ____________________ What is the recommended route of administration? ____________________ What is the volume of diluent that was added to the vial? ________________ How long would the medication be potent after reconstitution? _________________ What is the strength of medication per milliliter? _______________________ What volume of medication should be administered to the patient? _______________________ What total volume of medication is in the vial after reconstitution? _______________________ What type of syringe should be used to administer the medication? _______________________ What volume of medication should be added to the IV fluids for this patient? _______________________ What is the milliequivalent per milliliter in this vial? _______________________ What is the total volume of medication of the vial? ________________ What is the total strength of medication in the vial? _______________ How many doses of medication are in this vial if the patient receives the same amount of medication for each dose? _______________________ Interpret the order. __________________________________________________________________ What volume of medication should be administered to the patient with each dose? _________________________ What is the total strength of the medication in the vial? __________ How many doses of medication can be administered from a single vial if the dosage remains the same? _______________________ What volume of medication would the patient receive? _______________________ What volume of medication would be available in the vial after this dose has been prepared? ______________________ Which syringe should be used to provide the most accurate dose of medication? _______________________ Indicate the dose that would be drawn for this order. Using an unopened vial of medications, what volume of medication should be added to the fluids? _____________ What volume of medication would be available in the vial after the dose of insulin has been prepared? __________________________ Choose the syringe that would provide the most accurate dose of medication and indicate the desired volume. What volume of medication should be prepared to meet the order? ____________ Which syringe would you choose to provide the most accurate dose to administer this medication? _______________________ Indicate the dose that would be drawn for this order. What volume of medication should be given for this order? _______________________ Which syringe should you choose for the order? _______________________ What is the total concentration of the medication in the vial? ___________________ Indicate the volume of medication on the correct syringe. Can this medication be mixed with other insulin preparations? ____________________ Indicate on the syringe the amount of medication that should be shown to the patient for appropriate administration at home. Which label strength of medication would be optimal to prepare the medication order? _______________________ What volume of medication should the patient receive when using the selected vial of medication? _______________________ Which syringe would be appropriate for administration of the medication? _______________________ Indicate the amount of medication on the appropriate syringe. Which vial of medication should be made available for administration? _______________________ Which syringe should be used for administration? _______________________ Indicate the amount of medication on the correct syringe. Choose the appropriate medication for completing the order. _______________________ What volume of medication should be administered to the patient using the appropriate medication label? _______________________ Indicate the correct amount of medication to be administered to prepare this order on the correct syringe. If 11.5 mL of diluent is added to this vial, what is the strength of the medication per milliliter? _______________________ For what length of time would the medication be acceptable for use after reconstitution? _______________________ What volume of medication should be added to IV fluids to complete this order as diluted above? _______________________ Indicate the needed documentation for the label following reconstitution using today’s date and time and initials as appropriate. ____________________ Choose the appropriate syringe that is necessary to add the penicillin to the fluids. What volume of medication should be administered? _______________________ On the following measuring device(s), show the volume of medication that should be administered. What volume of medication should be administered? _______________________ Which oral measuring device(s) could be used to administer this medication? _______________________ Indicate the amount to be administered on the correct measuring device(s). What volume of medication should be administered? _______________________ Which measuring device(s) should be used to administer this medication? _______________________ How could this be administered using a household measuring device? ______________ Indicate the amount to be administered on the correct utensil. How many units of medication would be available in each vial for future use when this dose of medication has been prepared? ________________ Using the syringes that follow, show the amount of regular insulin on one syringe, the amount of Lente insulin on another syringe, and the total amount of insulin on the final syringe. Percentages are the concentration of weight of a substance or medication dissolved in a solute, either by volume with liquids or weight with solids. (To review how to change a percentage to whole or decimal numbers see Chapter 2.) These medications have the label showing the percentage strength such as Lidocaine 1% or epinephrine 0.1%. Solutions expressed in ratio strengths provide information concerning the ratio of medication to the amount of solute. Penicillins G and V are products measured in the unit system, as are other antimicrobials such as nystatin suspension. In many cases, these medications are available in a powdered form that requires reconstitution before administration. The information on the drug label will inform you about the type and amount of needed diluent. If the label does not specify the needed diluent, in most cases the diluent will be provided with the powdered medication. In some cases the label also provides different strengths for the medication that can be prepared by the amount of diluent added (Figure 11-1). If you need to review the necessary steps for reconstitution of medications, see Chapter 9. Practice Problems A 1. What volume of diluent should be added to the medication for the strength to be 500,000 units/mL? ____________________ What volume of medication should be added to the IV fluids? _______________________ What volume of medication would be left in the vial after medication is prepared? _______________________ Should the residual medication be diluted to another dosage strength? _______________________ Explain your answer ____________________ Which syringe for injection should be used to prepare the medication for addition to IV fluids? _______________________ 2. What amount of diluent is added to the vial for medication strength of 250,000 units/mL? _______________________ What volume of medication should be prepared for a patient dose? _______________________ What volume of medication would remain in the vial following preparation of the ordered medication? _______________________ Show the documentation that would be needed on the vial, using today’s date and time as guide if necessary. _______________________ How long would the medication be stable in the vial following reconstitution? _______________________ Which syringe should be used to add the medication to the IV fluids? _______________________ 3. What volume of medication should be given to the patient with each dose? _______________________ Which measuring device should be included with the prescription for the patient to take the medication at home? _______________________ What is the measurable dose? _______________________ If the patient should misplace the measuring device provided, how could this be estimated using household utensils? _______________________ 4. 5. What volume of medication should be administered to the patient daily? _______________________ What type of syringe would be needed to administer this strength of medication? _______________________ 6. Interpret the order. __________________________________________________________________ What volume of medication should be administered with each dose? _______________________ Show the correct amount of medication on the correct syringe in the following illustrations. 7. If 4 mL of diluent is added to the vial, what is the resultant strength of the penicillin? _______________________ What volume of medication should be prepared for administration? _______________________ How long would this medication be stable after reconstitution? _______________________ Where should the medication be stored after reconstitution? _______________________ What is the total strength of medication in the vial? _______________________ Mark the label with the correct documentation following reconstitution, using today’s date, time, and initials if applicable. What size syringe should be used for administration of the drug? _______________________ 8. What volume of medication should be administered with each dose? _______________________ If the dose is to be divided between each side of the mouth, what volume of medication should be placed in each side? _______________________ Which measuring device would provide the dosage amount most accurately? _______________________ Indicate the amount of medication on the measuring device to be used. 9. Interpret the order. _______________________________________________________________ What volume of medication should be administered to the patient? _______________________ How can this be administered using household measuring devices? _______________________ Indicate the amount of medication on the measuring device to be used. 10. What are the directions for storing this medication? _______________________ What volume of penicillin should be administered to this patient? _______________________ 11. What volume of medication should be administered to the patient? _______________________ What is the measurable dose of medication? _______________________ Which syringe should be used to provide the medication? _______________________ Indicate the amount of medication on the proper syringe. 12. What is the appropriate concentration of penicillin G potassium on the label for dispensing the medication for this order? _______________________ What volume of diluent should be added to prepare the medication for administration of the desired dose? _______________________ What volume of medication is to be administered following reconstitution? _______________________ What is the proper storage of this medication following reconstitution? _______________________ Show the proper documentation for the reconstitution on the label provided; use today’s date, time, and initials as appropriate. Which syringe is appropriate for the administration of the medication? _______________________ 13. What volume of medication should be administered? _______________________ Show the volume of diluent to be added on the proper syringe. Show the volume of medication to be administered on the proper syringe. Label each syringe with either diluent or medication. 14. What volume of medication should be administered? _______________________ What is the measurable dose? _______________________ Show the volume of medication on the correct syringe for administration. 15. What is the total dosage of medication to be given in a day? _______________________ What is the measurable dose in a 3 mL syringe? _______________________ What volume of medication is to be given to the patient to provide each ordered dose? _______________________ 16. What volume of medication should be administered? _______________________ If the medication must be measured from a vial, what syringe should be provided to accurately measure the medication for administration? _______________________ 17. What total dose of medication should be given in a day? _______________________ What dose of medication should be administered with each dose? _______________________ What volume of medication should be administered per dose if the label reads penicillin G 1,000,000 units/50 mL? _______________________ 18. 19. 20. What volume of medication should be administered to this patient with each dose? _______________________ What measuring device should be included with the prescription for home administration? _______________________ Mrs. Jones calls and states the measuring device given to her to take the medication was stepped on and broken. How would you tell her to take the medication using a household measuring device? _______________________ Explain why using the household measuring device would not provide an accurate dose of medication. _________________________________________________________________ Insulin, which is used to control type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in some persons whose elevated blood sugar cannot be adequately controlled with oral hypoglycemics, is prescribed and measured in units. Most insulin preparations are only available in U-100 strength, meaning that each milliliter of insulin contains 100 units of medication. Even insulin preparations that are combinations of regular insulin and intermediate-acting insulins are in U-100 specifications. See Figure 11-2 for labels for different insulin preparations. To administer insulin preparations, insulin syringes that are calibrated in 100 units/mL must be used; no other syringe is based in units for insulin (in an emergency a tuberculin syringe could be used because it is also calculated in hundredths of milliliters). The design of the syringe makes it easy to ensure that the exact dose of medication ordered is administered. Syringes come in 30-, 50, and 100-unit calibrations (Figure 11-3). Some 100-unit insulin syringes are available in two-unit increments, while others are marked in one-unit increments with two-unit increments of odd/even on each side of the syringe barrel. To further complicate matters when preparing insulin for administration, you will find some syringes are in one-unit increments with the markings on the same side of the syringe. Please note that syringes holding a smaller quantity such as 30-unit and 50-unit syringes are in one-unit increments and are easier to use by patients who have visual problems, a common complication of long-term or uncontrolled diabetes mellitus. Insulin syringes should not be used for measuring any medication other than insulin—not even for heparin or antibiotics.
Calculation of Medications Measured in Units, Milliequivalents, and Percentages of Concentration
1 A physician orders Acthar Gel 50 units IM stat. The medication on hand has a label reading Acthar Gel 80 units/mL.
2 A physician orders heparin sodium 1500 units subcutaneously stat. Use the label provided for calculations.
3 A physician orders 750,000 units of penicillin G IM stat for a male teenager who has pneumonia. Use the following label to calculate this information. The medication is reconstituted to 500,000 units/mL.
4 A physician orders penicillin G potassium 500,000 units IM for an adult. Add 1.8 mL of sterile water and use the label provided to answer questions.
5 A physician orders potassium chloride 2 mEq to be added to IV fluids for a patient in electrolyte imbalance. Using the following label, calculate the necessary dose.
6 A physician orders 500,000 units of penicillin G IM stat and q6h. The available medication is penicillin G 250,000 units/mL in a 10-mL vial.
7 A physician orders 2500 units of heparin sodium subcutaneously. The medication available is 10,000 units/mL in a 1 mL vial.
8 A physician orders Humulin R 50 units in IV fluids to make an insulin infusion.
9 A physician orders Humulin R 35 units subcutaneously stat. The available medication is shown on the previous label.
10 A physician orders procaine penicillin G 1,000,000 units IM. The medication available is a 10-mL vial of procaine penicillin G 250,000 units/mL.
11 A physician orders Lantus insulin glargine 55 units subcutaneously to be given daily at bedtime. The medication available is shown on the following label.
12 A physician orders 17,000 units of heparin sodium subcutaneously as a stat dose. The available medications are shown on the following labels.
13 A physician orders heparin sodium 750 units subcutaneously as a stat dose. Available are the following labels for preparing the medication for the order.
14 A physician orders a heparin sodium flush 45 units to be administered q12h to keep an intravenous site patent. The available medications are shown on the following labels.
15 A physician orders penicillin G potassium 10,000,000 units to be given IV stat. Use the following label to complete this order.
16 A physician orders V-Cillin K suspension 300,000 units q6h. The available medication is V-Cillin K suspension 200,000 units/5 mL.
17 A physician orders Mycostatin oral suspension 250,000 units to be swished and swallowed. The medication is available as shown in the following label.
18 A physician orders Kaon-Cl 40 mEq po qam. The available medication is Kaon-Cl 40 mEq/15 mL.
19 A physician orders Klor-Con (KCl) 10 mEq daily. The available medication is Klor-Con 20 mEq scored tablet.
20 A physician provides a new prescription for Humulin R 12 units and Humulin N 35 units subcutaneously qam. Use the following labels to calculate the medication for this order.
Introduction
Calculating Dosages in Unit and Milliequivalent Measurements
Calculating Antibiotics Measured in Units
A physician orders penicillin G potassium 750,000 units to be added to IV fluids for a postoperative patient. The following label is the medication available for use for administration.
A physician orders Pfizerpen 800,000 units to be added to IV fluids. Use the label in Problem No. 1 for calculation.
A patient with severe bronchitis has an order for penicillin V 250,000 units qid. The medication on hand is oral penicillin V 400,000 units/5 mL.
A physician orders V-Cillin K tablets 800,000 units to be given bid. The available medication is V-Cillin K 400,000-unit tablets.
A physician orders penicillin G 450,000 units IM daily for 4 days. The available medication is penicillin G 300,000 units/mL.
A physician orders penicillin G 750,000 units IM q12h for a patient with a severe bacterial infection. The available medication is penicillin G 300,000 units/mL.
A physician orders penicillin G 500,000 units IM q6h. The label reads 1,000,000 units/vial.
A physician orders Mycostatin Oral Suspension 300,000 units to be administered bid in divided doses for each side of mouth. The available medication is shown on the following label.
A physician orders penicillin V oral suspension 200,000 units po qid. The medication available is penicillin V oral suspension 400,000 units/5 mL.
A physician orders penicillin G procaine suspension 600,000 units IM bid for a patient with a severe infection. The available medication is shown on the following label.
A physician orders Bicillin L-A 425,000 units IM. The available medication is found on the following label.
A physician orders penicillin G potassium 450,000 units IM as a stat dose. The available medication is on the following label.
A physician orders penicillin G 300,000 units IM. A medication vial containing penicillin G 5,000,000 units is available. Directions for reconstitution state to add 8 mL of sterile water to provide a 500,000 units/mL medication.
A physician orders penicillin G potassium 125,000 units q6h. The vial contains penicillin G potassium 1,000,000 units. The reconstituted strength is penicillin G potassium 250,000 units/mL.
A physician orders penicillin G potassium 50,000 units/kg/d in two divided doses for a patient who weighs 220 lb. The available medication is penicillin G potassium 2,000,000 units/mL.
A physician orders penicillin G benzathine 2,400,000 units IM stat for syphilis. The available medication label reads penicillin G benzathine 600,000 units/mL.
A physician orders penicillin G IV for severe strep throat for a 66-lb child to prevent strep pneumonia. The normal dose is 150,000 units/kg/day in four divided doses.
A physician orders Mycostatin 200,000 units at bedtime vaginally for a patient with a Candida infection. The available medication is labeled Mycostatin Vaginal Suppositories 100,000 units.
A patient is being given prophylactic treatment for rheumatic fever. The physician orders penicillin G benzathine 1,200,000 units qmo for this patient. The medication is available as penicillin G benzathine 300,000 units/mL for IM administration.
Mrs. Jones, an elderly patient, has chronic sinusitis. The physician orders penicillin V 300,000 units po qid. The available medication is penicillin V 400,000 units/5 mL.
Calculating Insulin Doses in Units
< div class='tao-gold-member'>
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
Calculation of Medications Measured in Units, Milliequivalents, and Percentages of Concentration
Only gold members can continue reading. Log In or Register to continue
