Liquid Oral Medications (cont.)

To calculate the volume of liquid oral medication to administer, use: – proportion

– formula

– dimensional analysis

QHD

A

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.

Calculating Dosages –Liquid Oral Medications (cont.)

H = 2 mg ; Q = 10 mL; D = 5 mg

Step A Convert

No conversion is necessary.

Calculating Dosages –Liquid Oral Medications (cont.)

Step B Proportion H/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

Calculating Dosages –Oral Solid Medications (cont.)

Step B Dimensional analysis

A = Q/H x D/1

A mL = 10 mL/2 mg x5 mg/1

A mL = 50 mL/2

A mL= 25 mL

Calculating Dosages –Oral Solid Medications (cont.)

Step B Formula Method

5mg/2mg x 10 mL = A

50 mL/2 = A

25 mL = A

AxQHD

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.

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.

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