2. Liquid Oral Medications (cont.) To calculate the volume of liquid oral medication to administer, use: –proportion –formula –dimensional analysis

3. Liquid Oral Medications (cont.) Find the amount to administer. Ordered: Granisetron 5 mg PO now On hand: Granisetron 2 mg per 10 mL oral solution Use the calculation method of choice.

4. Calculating Dosages – Liquid Oral Medications (cont.) H = 2 mg ; Q = 10 mL; D = 5 mg Step A Convert No conversion is necessary.

5. Calculating Dosages – Liquid Oral Medications (cont.) Step B ProportionH/Q = D/A or H:Q = D:A 2 mg / 10 mL = 5 mg / A 2 x A = 10 mL x 5 2A / 2 = 50 mL / 2 A = 25 mL

6. Calculating Dosages – Oral Solid Medications (cont.) Step B Dimensional analysis A = Q / H x D / 1 A mL = 10 mL / 2 mg x 5 mg / 1 A mL = 50 mL / 2 A mL= 25 mL

7. Calculating Dosages – Oral Solid Medications (cont.) Step B Formula Method 5mg / 2mg x 10 mL = A 50 mL / 2 = A 25 mL = A

8. Calculating Dosages – Liquid Oral Medications (cont.) Step C Think!... Is It Reasonable? 5 mg is two and one-half times 2 mg, and 25 mL is 2.5 times 10 mL, so it is a reasonable amount.

9. Patient Education Use the measuring device provided or a device specifically made for measuring medications. –Household teaspoons and tablespoons do not always measure liquids accurately.

10. Practice Ordered: Erythromycin oral suspension 0.5 g po q6 h On hand: see label (prior slide) What is the amount to administer? ANSWER: 12.5 mL