You receive a new order for doxycycline for a Carrie, a 0.8 lb parrot. Doxycycline for this particular patient should be dosed at 25 mg/kg given twice daily for 45 days.
(A) How many milligrams of doxycycline should Carrie get for each dose?
(B) The vet asks that you compound a suspension so the bird gets 0.5 mL twice daily. Using the contents of doxycycline 100 mg capsules, how many capsules will you need and what will your total volume be?
My answers:
(A) 9 mg
(B) 9 capsules; 45 mL (but the answer key says 50 mL)
To calculate the dosage for Carrie, the parrot, we need to follow a few steps:
(A) How many milligrams of doxycycline should Carrie get for each dose?
Step 1: Convert Carrie's weight from pounds to kilograms.
0.8 lb = 0.8 / 2.2046 kg ≈ 0.3636 kg
Step 2: Calculate the total dosage required per day.
Dosage = 25 mg/kg × 0.3636 kg = 9.09 mg
Step 3: Divide the total dosage per day by the number of doses given per day.
Dosage per dose = 9.09 mg ÷ 2 = 4.55 mg
Therefore, Carrie should receive approximately 4.55 mg of doxycycline for each dose.
(B) The vet asks that you compound a suspension so the bird gets 0.5 mL twice daily. Using the contents of doxycycline 100 mg capsules, how many capsules will you need and what will your total volume be?
Step 1: Determine the total amount of doxycycline required per day.
Total dosage per day = 9.09 mg × 2 = 18.18 mg
Step 2: Convert the total amount of doxycycline required into the number of 100 mg capsules needed.
Number of capsules needed = Total dosage per day ÷ 100 mg
Number of capsules needed = 18.18 mg ÷ 100 mg ≈ 0.182 capsules
Since we can't use a fraction of a capsule, we round up to the nearest whole number. Therefore, 1 capsule is needed.
Step 3: Calculate the total volume required for the suspension using the capsule contents.
Capsule volume = 100 mg ÷ 25 mg/mL
Capsule volume = 4 mL
To prepare a suspension with a dosage of 0.5 mL per dose, we divide the capsule volume by the dosage per dose.
Total volume = Capsule volume ÷ Dosage per dose
Total volume = 4 mL ÷ 0.5 mL = 8 mL
So, to provide a dosage of 0.5 mL of the compounded suspension twice daily, you will need approximately 1 capsule and the total volume of the suspension will be 8 mL.
Therefore, your answers are:
(A) Carrie should receive approximately 4.55 mg of doxycycline for each dose.
(B) You will need 1 capsule, and the total volume of the suspension will be 8 mL.