1. Parentral Drug Administration

2. Intravenous administration
Drug is introduced directly into the venous circulation
IV and intra-arterial administration: no biological membranes to be crossed
Used when rapid clinical response is required
Plasma conc time curve: rate and duration of injection, rate of distribution and elimination
IV dose volume: 1 ml- 500 ml
Peripheral vs central veins
IV infusion, loading dose
Administration of prodrugs: dexamethasone phosphate vs sulphate

4. IV injection sites

5. Intramuscular adminsitration (IM)
Delivery of exact? quantities with differences in the rate
Drugs that are not absorbed orally, rapid blood levels as IV are not required
Volume: 2-4 ml
IM injection: solution, aq suspension, oily suspensions, oily soln
Factors that influence abs rate: Vascularity of the injection site
Degree of ionization
Lipid solubility
Volume of injection
Site of administration: arm (deltoid), thigh (vastus lateralis), buttocks (gluteus maximus)
Complete and prompt absorption cannot be assured (chlordiazepoxide)
Untoward local effects: mechanical aspects of the injection, properties of the drug and solvent
IM dosage for sustained release

6. Deltoid
Should not be used in infants or children because of the muscle’s small size.
Injection volume should not exceed 1ml in the adult
Use a gauge, 5/8 to 1 inch needle
Rarely used for hospitalized patients. Primarily used for immunizations.

7. Vastus Lateralis
Identify the greater trochanter and the lateral femoral condyle
Select the site using the middle third and the anterior lateral aspect of the thigh.

8. Sites for IM injections

9. Subcutaneous injection
Injections are made under the skin into the subcutaneous tissue
Volume: 1.0 ml or less
Abs may be enhanced by massage, heat, vasodilators
Insulin
Vascularity