1. Parenteral Dosage of Drugs
Chapter 11
MAT 119

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

4. Z-Track Injection Z-Track

5. 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.

6. 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

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

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

9. Parenteral dosages
Round amount to be administered to tenths if the amount is greater than 1 mL and measure it in a 3 mL syringe Order: Administer 1.33 mL = 1.3 mL

10. Parenteral dosages
Measure amounts less than 1 mL rounded to hundredths and all amounts less than 0.5 mL in a 1 mL syringe.
Order: Administer 0.65 mL

11. Parenteral dosages
Amounts of 0.5 mL to 1 mL calculated in tenths can be accurately measured in either a 1 mL or a 3 mL syringe (usually use 3 mL for IM > 0.5 mL)
Order: Administer 0.6 mL

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

13. Three Steps Step 1: Convert Step 2: Think Step 3: Calculate
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

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

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

16. Calculation of Drug Dosage: Parenteral
Order: Robinul 100 mcg IM stat
Supply: Robinul 0.2 mg per mL
Convert: Equivalent: 1 mg = 1,000 mcg
0.2 mg = = 200 mcg
Think: Give less than 1 mL 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

17. continued Order: Robinul 100 mcg IM stat Supply: Robinul 0.2 mg per mL
Step 3: Calculate:

18. continued Give IM Select a 1 mL syringe
Measure 0.5 mL Robinul 0.2 mg per mL
You have to change needles, as this is an IM injection.
Change to
1-1 1/2”
needle

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

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

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

22. 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

23. 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

24. Types of Insulin

25. Other Delivery Systems Insulin Pump

26. Inhaled Insulin

27. Insulin Sliding Scale No coverage Glucose less than 160 2 units
Insulin Dose
Glucose Reading*
No coverage
Glucose less than 160
2 units
160–220
4 units
221–280
6 units
281–340
8 units
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

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