Unit 45 Calculating Parenteral Dosage Basic Principles of

Unit 45 Calculating Parenteral Dosage

Basic Principles of Calculating Parenteral Dosage • Parenteral medications are medications that are injected into the body. • Some different types of injections include: – Subcutaneous (SC) injected just below the surface of the skin – Intramuscular (IM) injected into a muscle – Intravenous (IV) injected into a vein

Basic Principles of Calculating Parenteral Dosage • Parenteral medications are supplied as liquids because they are injected into the body. • The strength of the medication is usually written as a measurement of weight in a measurement of volume, such as 250 mg/m. L. • Syringes are used to measure the proper volume amount that is given.

Basic Principles of Calculating Parenteral Dosage • Correct dosage for parenteral medications can be calculated by using either the proportion method or the formula method used to calculate oral dosage. • Remember that all units of measurement must be the same.

Calculating Parenteral Dosage • Example: A doctor orders streptomycin 500 mg IM. The dosage available for use contains 1 gram (g) per 2 milliliters (m. L). How many m. L should be injected? – Use the proportional method: 1, 000 X = 1, 000 X=1 • The correct dose is 1 m. L.

Practical Problem • A physician orders an injection of 45 micrograms (mcg) of vitamin B 12 for a patient with pernicious anemia. It is available as 300 mcg in 10 m. L. • How many m. L should be injected?

Practical Problem • Set up a proportion: 300 X = 450 X = 1. 5 The correct dose is 1. 5 m. L.