Dosage Cal.docx

Doctor's order: 0.9% NaCl solution at 50 mL per hour How many gtts per minute should be administered if the tube delivers 20 gtt/mL? X gtts per min = (50 x 20)/60 = 1000/60 = 16.6 gtts which rounded off to the closest drop is 17 gtts Rounded off to: 17 gtt/min Doctor's order: Meperidine 20 mg IM q4h prn for pain Medication label: Meperidine 40 mg/mL How many mL or cc will you give for each prn dose? 20 mg / x mL = 40 mg/1mL 40mg * x = 20mg * 1mL x = 20mg/40mg * 1mL = 0.5 mL Doctor's order: Heparin 3,000 units subcutaneously Medication label: 5,000 units/mL How many milliliters will be administered for this patient?

Patient: 34 cm tall, 5 kg Ordered: Cerubidine 5.5 mg IV weekly On hand: Cerubidine injection 5mg/mL Recommended pediatric dose 25 mg/m2 If dose is safe, calculate amount to administer: BSA = 0.23 m2 Desired dose = 5.8 mg Dose ordered is a safe dose. Amount to administer = 1.2 mL Step A Convert height and weight to BSA m2.Sq root of 34cm x 5 kg/3131BSA = 0.23 m2 Step B Calculate desired dose.25 mg/ m2 x 0.23 m2 = D [cancel units (m2)]5.8 mg = D Step C Desired dose is less than maximum recommended dose of mg / m2. Calculate amount to administer. Step A No conversion is needed. Step B H = 5 mg Q = 1 mL D = 5.8 mg 5.8 mg/5 mg x 1 mL = A1.2 mL = A

5,000 * X = 3,000 3,000/5,000 = 0.6 mL Answer: 0.5 mL Doctor's order: Tetracycline syrup 150 mg po once daily Medication label: Tetracycline syrup 50 mg/mL How many mL should be administered per day? For this oral dosage problem you have to find out how many mL of tetracycline the patient will get when the doctor has ordered 150 mg and the syrup has 50 mg/ml. 150 mg: x mL = 50 mg: 1 mL 50 x = 150

Methicillin sodium 1.5 g, IM, q12h, daily for 5 days, was prescribed for a systemic infection. 4 g of the medication is available as a powder in vial. Directions state to reconstitute with 5.7 mL of sterile water for injection and shake well. Solution concentration will provide 500 mg/mL.
X = 150/50 = 3 mL

Doctor's order: 125 mg of medication once a day Medication label: 1 tablet = 250 mg How many tablets should be administered daily? In this problem you have to determine how many tablets the patient will take if the doctor order is 125 mg a day and the tablets are manufactured in tablets and each tablet has 250 mg. . 125 mg: x tablets = 500 mg: 1 tablet 125 x = 500 mg X = 125/500 = 1/4 tablet

How many mg of NaHCO3 solution would be needed to prepare 40 oz of 1:100 NaHCO3 solution? 40 oz/ 0.01 = 1200000/ 0.01 = 12000 mg B. How many mL of the 1:100 NaHCO3 solution was prepared? (Note: 1 oz = 30 mL) 40 oz (30 ml/1 oz) = 1200 mL Sample: MD orders 300 mg of Ibuprophen to be taken by a 6 kg infant every 4 hours. Label shows 75 – 150 mg/kg per day. Is the physician’s order within normal range? Solution: 6 x 75 = 450 mg (minimum dosage per day); 150 X6 = 900 (maximum dosage per day) 24 ÷ 4 = 6 dosages : 300 x 6 = 1800 Answer: Dosage is not within range

Give 750mg of Ampicillin q4h IV. On hand Ampicillin 1 g vial in powered form. Reconstitution directions say:add 2ml sterile water for injection. Each ml contains500mg Ampicillin. How many ml would you give each dose Use resulting concentration( 500mg/ml) 500 mg : 1ml :: 750 mg : x ml X= 1.5 ml So we would give 1.5ml for ordered dose. Penicillin G 2,250,000 units IM now. ON Hand: Penicillin 20 million unit vial Reconstitution reads:Add 11.5cc for 1,000,000 units/ml, 33cc for 500,000units/ml, and 75cc for 250,000 units/ml Using the appropriate concentration, how many ml should be given for this dose Choose 1,000,000 units/ml (since it is the closest) 1,000,000units :1cc :: 2,250,000units : xcc 1,000,000 x = 2,250,000x = 2.25cc give 2.25 cc to administer dose Order Oxycodone 3mg p.o. now Patient weighs 30 lbs. Recommended safe dose of Oxycodone is 0.15 mg/kg/dose Is this dose safe? 30 lbs / 2.2 = 13.64 kg. Recommended dose is 0.15 mg/kg/dose 0.15 x 13.64 = 2 mg is the maximum safe dose This dose is not safe!

Order: D5W Heparin 40,000 U in 1,000 mL D5W to infuse at 40 mL/h. What is the hourly heparin dosage? Find how many Units are in 40 mL. x U • 1,000 mL = 40,000 U • 40 mL = 1,600 units