Calculations of Basic Intravenous Infusion Solutions
1.A pharmacist receives a medication order for 300,000 units of penicillin G potassium to be added to 500 mL of D5W. The directions on the 1,000,000-unit vial state that if 1.6 mL of solvent are added, the solution will measure 2 mL. How many milliliters of the solution must be withdrawn and added to the D5W?
2.A medication order calls for acyclovir, 355 mg, to be administered by intravenous infusion over 60 minutes. A 500-mg vial of acyclovir is avail-able that must be mixed with sterile water for injection to prepare 10 mL of injection. The proper amount is then admixed with 100 mL of normal saline solution. Calculate (a) the volume to be taken from the vial of mixed acyclovir, (b) the rate of infusion in mL/min, and (c) the drops/min if using an intravenous set that delivers 20 drops/mL.
3.A medication order calls for a dopamine drip at 5 mg/kg/min for a 185-lb patient. The pharmacy adds 400 mg dopamine in 250 mL of D5W. Calculate the drip rates per minute when using administration sets delivering (a) 15 drops/mL, (b) 20 drops/mL, and (c) 60 drops/mL.
4.A solution containing 500,000 units of polymyxin B sulfate in 10 mL of sterile water for injection is added to 250 mL of 5% dextrose injection. The infusion is to be administered over 2 hours. If the administration set delivers 15 drops/mL, at what rate, in drops per minute, should the flow be adjusted to administer the infusion over the designated time interval?
5.An 8-kg infant requires a continuous infusion of a drug to run at 1 mL/hour to deliver 4 mcg of drug/kg per minute. Calculate the milligrams of drug that must be added to a 100-mL intravenous infusion solution.
6.A hospital pharmacist prepared thirty 100-mL epidural bags containing 0.125% of bupivacaine hydrochlo-ride and 1 mg/mL of fentanyl citrate in 0.9% sodium chloride injec-tion. How many (a) 30-mL vials of 0.5% bupivacaine hydrochloride, (b) 20-mL vials of 50 mg/mL of fen-tanyl citrate, and (c) 1-L bags of 0.9% sodium chloride were required?
7.If a physician orders 5 units of insulin to be added to a 1-liter intravenous solution of D5W to be administered over 8 hours, (a) how many drops per minute should be administered using an IV set that delivers 15 drops/mL, and (b) how many units of insulin would be administered in each 30- minute period?
8.Using the nomogram in Figure 13.5, determine the approximate rate of infusion delivery, in drops per minute, based on 1.5 liters of fluid to be used over a period of 8 hours with an infusion set calibrated to deliver 16 drops/mL.
9.The recommended maintenance dose of aminophylline for children is 1 mg/kg/hr by injection. If 10 mL of a 25 mg/mL solution of aminophylline is added to a 100-mL bottle of dextrose injection, what should be the rate of delivery, in milliliters per hour, for a 40-lb. child?
10.A patient is receiving 500 mL of an intravenous drip containing 25,000 units of sodium heparin in sodium chloride injection. Calculate (a) the administration rate, in mL/h, to deliver 1200 units of sodium heparin per hour and (b) the administration rate, in drops/min, with an IV set that delivers 15 drops/mL.
11.If the loading dose of phenytoin in children is 20 mg/kg of body weight to be infused at a rate of 0.5 mg/kg/min, over how many minutes should the dose be administered to a 32-lb. child?
12.If a medication order calls for a dobutamine drip, 5 mg/kg/min, for a patient weighing 232 lb. what should be the drip rate, in drops per minute, if the 125-mL infusion bag contains 250 mg of dobutamine and a micro-drip chamber is used that delivers 60 drops/mL?
13.A pharmacist places 5 mg/mL of acyclovir sodium in 250 mL of D5W for parenteral infusion into a pediatric patient. If the infusion is to run for 1 hour and the patient is to receive 500 mg/m2 BSA, what would be the rate of flow in milliliters per minute for a patient measuring 55 cm in height and weighing 10 kg?
14.An intravenous infusion contains 5 mg of RECLAST (zoledronic acid) in 100 mL. If the infusion is to be administered in 15 minutes, how many (a) milligrams of zoledronic acid, and (b) milliliters of infusion must be administered per minute? And (c), using a drip set that delivers 20 drops/milliliter, how many drops per minute must be infused?
15.TORISEL (temsirolimus), for use in advanced renal cell carcinoma, is prepared for infusion by adding 1.8 mL of special diluent to the drug vial resulting in 3 mL of injection containing 10 mg/mL of temsirolimus. The required quantity is then added to a 250-mL container of sodium chloride injection for infusion. The recommended dose of temsirolimus is 25 mg infused over 30 to 60 minutes. The quantity of drug delivered, in mg/mL, and the rate of infusion, in mL/min, for a 30-minute infusion are: (a) 0.099 mg/mL and 8.42 mL/min (b) 0.099 mg/mL and 8.33 mL/min (c) 1 mg/mL and 8.42 mL/min (d) 1 mg/mL and 8.33 mL/min
16.The mAb eculizumab is available in 30-mL vials containing 300 mg of drug. Prior to administration by intravenous infusion, the solution is diluted with sodium chloride injection to a concentration of 5 mg/mL. The dose of eculizumab is 600 mg infused over a 35-minute period. Calculate the rate of infusion in drops/min using an administration set that delivers 15 drops/mL.
17.The mAb natalizumab is available in vials containing 300 mg/15 mL. Prior to infusion, the contents are added to 100 mL of normal saline injection. Refer to Table 13.4 as needed, and calculate (a) the concentration of natalizumab in the infusion, in mg/mL, and (b) the rate of infusion, in mL/min.
Calculations on Plant Extractives
1.How many milliliters of a fluid extract would be equivalent in active ingredient to the following?
(a) 10 g of crude drug(b) 10 mL of a “potent” tincture(c) 10 g of a “300%” extract
2.How many milliliters of a “potent” tincture may be prepared from the following?
(a) 10 mL of a fluid extract(b) 10 g of a “400%” extract(c) 10 g of a “2X” extract
3.Cascara sagrada (bark) USP contains 7% of hydroxy anthracene derivatives, whereas the cascara sagrada extract USP contains 11 grams of hydroxy-anthracene derivatives in each 100 g. Calculate the “%” of the extract relative to the crude drug (e.g., “250%”).
4.How many milliliters of a cascara sagrada fluid extract can be prepared from a pound of cascara sagrada bark?
5.Powdered opium USP contains 10.25% of anhydrous morphine. How many grams of powdered opium should be used to prepare 100 mL of opium tincture USP, which contains 10 mg/mL of anhydrous morphine?
6.If senna leaves contain 25 mg of seen sides per gram of leaves, how many milligrams of seen sides would be contained in a formula for 1000 mL of a senna syrup that contains 250 mL of senna fluid extract?
7.SENOKOT syrup, a laxative, contains 1.7 mg standardized seen sides per milliliter. The maximum adult dose is 15 mL twice daily. How many milligrams of seen sides would a patient receive by taking the maximum dose?
8.If ginkgo Biloba contains 24% of ginkgo heterosides, and if 120 mg are taken daily in three divided doses, how many milligrams of the ginkgo heterosides are contained in each of the divided doses?
9. If milk thistle is standardized to contain 70% of silymarin, how many milligrams of this substance are contained in a 200-mg dose of milk thistle?
10.If Saint John’s wort is standardized to contain 0.3% of hypericin extract, how many milligrams of the extract would be taken daily when Saint John’s wort is administered as a 300-mg capsule taken three times a day?
11.The herb valerian is administered as an extract containing 0.8% valeric acid. How many milligrams of vale-ric acid would be contained in each 300-mg dose of valerian extract?