If a prescription for amoxicillin 150 mg PO q8h for 10 days is filled with...

To determine the correct volume of amoxicillin suspension per dose, use the given concentration and dose.

Prescription dose:150 mg per dose

Suspension concentration:250 mg per 5 mL

Formula to calculate volume needed:Volume (mL)=Prescribed dose (mg)Concentration (mg/mL)\text{Volume (mL)} = \frac{\text{Prescribed dose (mg)}}{\text{Concentration (mg/mL)}}Volume (mL)=Concentration (mg/mL)Prescribed dose (mg)​

Step 1: Identify Given InformationStep 2: Calculate150 mg250 mg/5 mL=150×5250=750250=3 mL\frac{150 \text{ mg}}{250 \text{ mg/5 mL}} = \frac{150 \times 5}{250} = \frac{750}{250} = 3 \text{ mL}250 mg/5 mL150 mg​=250150×5​=250750​=3 mL

Thus, the patient should take3 mL per dose.

B. 4 mL→ Incorrect; this would correspond to a different strength.

C. 5 mL→ Incorrect; this would deliver250 mg, which is incorrect.

D. 6 mL→ Incorrect; this would deliver300 mg, exceeding the prescribed dose.

Other Answer Choices Explained:References:

PTCB PTCE Exam Content Outline (Pharmaceutical Calculations – Dosage & Volume Calculations)

USP <795> Guidelines for Nonsterile Compounding & Drug Dilution

Lexicomp Drug Monograph for Amoxicillin Suspension