Question

Michael weighs 47 pounds. Order reads: Theophylline 125 mg po TID.

Recommended dose guidelines: 3-6 mg/kg q 8 hours PO. Supplied: 50 mg/ml.

Step 1: Weight in kg:                                                             _______________

Step 2: Safe dosage range:                                                     _______________

Step 3: Maximum safe dose for 24 hours:                             _______________

Step 4: Amount ordered for 24 hours:                                               _______________

Step 5: Is the order dose safe:                                                           _______________

Step 6: Calculate amount to be given for single dose:             _______________

Answer 1

Answer :

Step 1: Weight in kg: 21.36 Kg

Step 2: Safe dosage range: 64 mg - 128 mg /q 8 hours ( 192 - 384 mg/ day)

Step 3: Maximum safe dose for 24 hours: 384 mg/ day

Step 4: Amount ordered for 24 hours: 375 mg

Step 5: Is the order dose safe: Yes

Step 6: Calculate amount to be given for single dose: 2.5 mL/ dose

Step 1: Weight in kg: 21 Kg

2.2 lbs = 1 Kg

So 47 pounds = × ( cancel out lbs from numerator and denominator)

= Kg

= 21.36 Kg

Step 2: Safe dosage range:

Minimum safe dose for q 8 hours = × ( cancel out Kg from numerator and denominator)

=

Minimum safe dose for q 8 hours = 64.08 mg

Maximum safe dose for q 8 hour = × ( cancel out Kg from numerator and denominator)

=  

Maximum safe dose for q 8 hour = 128.16 mg

Safe Dosage range = 64.08 mg - 128.16 mg / q 8 hours

Step 3: Maximum safe dose for 24 hours:

( cancel out ‘Kg’, ‘hours’ from numerator and denominator)

ie Maximum safe dose for 24 hours = 384.48 mg/ day

Step 4: Amount ordered for 24 hours:

Order : Theophylline 125 mg po TID.

ie 125 mg × 3 = 375 mg

Step 5: Is the order dose safe:  

Safe dosage range between 64 mg to 128 mg q8h, ordered dose is 125 mg TID. So ordered dose is safe.

Step 6: Calculate amount to be given for single dose:   

Order : Theophylline 125 mg po TID,  Supplied medicine contains Theophylline 50 mg/ml.

Use the following formula to find out the amount of medicine to be administred

mL per dose =

mL per dose = ( cancel out mg from numerator and denominator)

= 2.5 mL