Parenteral Dosage of Drugs Chapter 11 MAT 119

Parenteral Dosage of Drugs Chapter 11 MAT 119

Parenteral Routes • Route of administration other than gastrointestinal – Intramuscular (IM) – Subcutaneous (subcut) – Intradermal (ID) – Intravenous (IV) 2

3

Z-Track Injection Z-Track 4

Parenteral Routes Used to describe drugs given by any route other than oral, sublingual, topical, or rectal • Generally associated with drugs administered by a needle • The term “parenteral” means by injection. 5

Parenteral Routes • Benefits: Good for drugs that are poorly absorbed, rapid response, patient is uncooperative, unconscious, etc. • Disadvantage: Expensive, require skilled personnel, is an invasive technique 6

Parenteral Routes All routes have limitations: • Limited to solutions, suspensions, and emulsions • Must be sterile (bacteria-free) • p. H must be maintained • May require buffers • Volume limited (IM, ID, Subcut) 7

Parenteral Medications • Most parenteral medications are prepared in liquid form and packaged in single, or multi-dose vials – Ampules or prefilled syringes 8

Parenteral dosages Round amount to be administered to tenths if the amount is greater than 1 m. L and measure it in a 3 m. L syringe Order: Administer 1. 33 m. L = 1. 3 m. L 9

Parenteral dosages • Measure amounts less than 1 m. L rounded to hundredths and all amounts less than 0. 5 m. L in a 1 m. L syringe. • Order: Administer 0. 65 m. L 10

Parenteral dosages • Amounts of 0. 5 m. L to 1 m. L calculated in tenths can be accurately measured in either a 1 m. L or a 3 m. L syringe (usually use 3 m. L for IM > 0. 5 m. L) • Order: Administer 0. 6 m. L 11

Calculation of Drug Dosage: Parenteral Order: Cleocin 150 mg IM q 12 h Available: Cleocin (clindamycin phosphate) 300 mg per 2 m. L 12

Three Steps • Step 1: Convert – All units of measurement must be in same system and all units must be in same size • Step 2: Think – Estimate logical amount • Step 3: Calculate Dosage on hand = Dosage desired Amount on hand X amount desired 13

Cleocin 150 mg IM q. 12 h Available: Cleocin (clindamycin phosphate) 300 mg per 2 m. L • Step 1: Convert – No conversion is necessary • Step 2: Think – You want to give less than 2 m. L – Actually, you want to give 150 mg, which is 1/2 of 300 mg and 1/2 of 2 m. L, or 1 m. L – Calculate to double-check your estimate 14

Cleocin 150 mg IM q. 12 h Available: Cleocin (clindamycin phosphate) 300 mg per 2 m. L • Step 3: Calculate 300 mg = 150 mg 2 m. L X Give 1 m. L Cleocin IM every 12 hours 15

Calculation of Drug Dosage: Parenteral • Order: Robinul 100 mcg IM stat • Supply: Robinul 0. 2 mg per m. L Convert: Equivalent: 1 mg = 1, 000 mcg 0. 2 mg = 0. 200 = 200 mcg Think: Give less than 1 m. L about 1/2 Don’t be fooled into thinking 0. 2 mg is less than 100 mcg 0. 2 mg is more than 100 mcg 0. 2 mg = 200 mcg 16

continued • Order: Robinul 100 mcg IM stat • Supply: Robinul 0. 2 mg per m. L Step 3: Calculate: 17

continued • Give IM • Select a 1 m. L syringe • Measure 0. 5 m. L Robinul 0. 2 mg per m. L • You have to change needles, as this is an IM injection. • Change to 1 -1 1/2” needle 18

Insulin Label Find: Supply dosage/concentration Total volume Brand name Type Manufacturer Label alerts Generic Name Species 19

Insulin • Supply dosage of insulin is 100 units per m. L • Abbreviated on label as U-100 • Syringe must also be U-100 • Accuracy is critical • Nurses must understand correctly interpret insulin order and label • The correct syringe must be selected 20

Insulin Syringes Standard U-100 50 Lo-Dose U-100 30 Lo-Dose U-100 21

Interpreting the Insulin Order • Brand name, including the species and action time. – Rapid-acting (Regular) – Intermediate-acting (NPH) – Long-acting (Lantus) • Supply dosage (concentration and number of units to be given) • Route of administration and time or frequency – Regular insulin only type to be given IV 22

Examples • Humulin R Regular U-100 insulin 14 units subcut stat • Novolin N NPH U-100 insulin 24 units subcut 1/2 hour ā breakfast 23

Types of Insulin 24

Other Delivery Systems Insulin Pump 25

Inhaled Insulin 26

Insulin Sliding Scale Insulin Dose Glucose Reading* No coverage 2 units 4 units 6 units 8 units Glucose less than 160– 220 221– 280 281– 340 341– 400 *Glucose greater than 400: Hold insulin, call MD stat Order: Humulin R Regular U-100 insulin subcut a. c. based on sliding scale p. 229 #26 -30 27

Insulin: Avoiding Errors • Check dosage with two nurses • When combination dosages are prepared, two nurses must verify each step of the process. 28

29