Dosage Calculations Flashcards
7 cards from real PTCE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Dosage Calculations flashcards as text
A 1:1000 epinephrine solution contains how many mg/mL?
Answer: 1 mg/mL
1:1000 means 1 g per 1,000 mL = 1,000 mg/1,000 mL = 1 mg/mL.
A patient weighing 88 lbs requires gentamicin 2.5 mg/kg IV. The vial is 40 mg/mL. How many mL to draw up?
Answer: 2.5 mL
88 ÷ 2.2 = 40 kg; 40 × 2.5 = 100 mg; 100 ÷ 40 mg/mL = 2.5 mL.
An order is for 0.9% NaCl 250 mL to infuse over 90 minutes. What is the rate in mL/hr?
Answer: 167 mL/hr
250 mL ÷ (90/60 hr) = 250 ÷ 1.5 = 166.7 ≈ 167 mL/hr.
Acetaminophen elixir 160 mg/5 mL is ordered; dose is 480 mg. How many teaspoons is this?
Answer: 3 tsp
480 ÷ (160/5) = 480/32 = 15 mL; 15 mL ÷ 5 mL/tsp = 3 tsp.
A drug is available as 10 mg/5 mL. An elderly patient needs 7.5 mg. How many mL should be given?
Answer: 3.75 mL
7.5 mg ÷ (10 mg/5 mL) = 7.5 × 5/10 = 3.75 mL.
A powder for reconstitution says: 'Add 9.3 mL water to yield 10 mL of 100 mg/mL suspension.' If a dose of 250 mg is needed, how many mL are given?
Answer: 2.5 mL
250 mg ÷ 100 mg/mL = 2.5 mL.
A pharmacy receives an order for prednisone 'taper': 40 mg daily × 3 days, 20 mg daily × 3 days, 10 mg daily × 3 days. Only 10 mg tablets are available. How many total tablets are dispensed?
Answer: 27 tablets
(4 tabs × 3) + (2 tabs × 3) + (1 tab × 3) = 12 + 6 + 3 = 21 tablets.