(3) Parenteral Routes of Administration

Intradermal (ID)

injection area just below the surface of the skin - interface of epidermis and dermis

ID use

skin tests, desensitization, or immunization

ID volume

limited to small quantities

• usually 0.1mL

• as small as 0.02 mL

• as large as 0.5 mL

ID needle size

25-30 gauge x 3/8 to 5/8 in

ID syringe size

1 mL

Subcutaneous (SC, SQ, SubQ)

injection area of fat tissue located beneath the skin between the dermis and muscle

SubQ uses

• acute or continuous therapies

• e.g. insulin, heparin, pain meds, hormones, biologics

SubQ volume

• limited to ~2.5 mL acutely

• depends on type of infusate (<60 mL/hr, frequently <10 mL/hr)

SubQ Hypodermoclysis

hydration with or without hyaluronidase, which facilitates faster fluid absorption

SubQ needle size

• insulin 30-32 gauge x ½ in

• others often 25 gauge x ½ to 5/8 in

SubQ syringe size

1-3 mL

SubQ injection sites

rotate injection sites to reduce risk of abscess, sloughing, induration, necrosis, or other tissue damage that may impair absorption or result in cosmetic changes

Intramuscular (IM)

injection area in muscle mass, formulations must be nonirritating

IM volume

limited by mass of injected muscle and age

• children <3 upper limit 1 mL

• adult upper limits 2 mL deltoid, 5 mL gluteal

IM recommendation for <3 y/o

vastus lateralis (outer thigh)

IM syringe size

1-5 mL

IM needle size

20-23 gauge x ½ to 1.5 in

Intravenous (IV)

injected into veins for administration of a drug that needs immediate systemic circulation, is irritating, and/or requires controlled blood levels; route of administration is restricted by size of vein chosen for administration, medication, and/or patient specific variables

IV needle size

20-23 gauge x ½ to 1.5 in

Peripheral catheter

• most common venous access

• short duration of use

• limitations on what can infused and at what rate

Central catheter

• more complicated and riskier to insert and maintain

• longer duration of use (days to months)

• fewer restrictions, allowing for:

  • higher concentration of drug

  • increased rate of administration

  • increased tolerance to irritating pharmaceutical agents

Bolus (IV Push) advantages

• immediate blood levels

• does not require prolonged continuous monitoring related to administration

• does not require pump/tubing or associated administration supplies and as such typically is the less expensive

• shortest duration of administration

IV push disadvantages

• drug toxicity may be increased due to rapid blood concentrations, peak blood/tissue concentrations or vein/tissue damage due to concentrated formulations required

• stability may be affected by higher concentrations required

• increased fluctuation of blood levels

• administration requires dedicated attention of resources

Continuous IV advantages

• simultaneous fluid and drug therapy

• allows for constant blood levels

• minimizes vein irritation/trauma

• reduces preparation/administration requirements

Continuous IV disadvantages

• requires greater monitoring

• may require central catheter placement

• infiltration or extravasation

• potential for rapid administration of too high a dose/volume and adverse drug event

Intermittent IV advantages

• limited admin time

• requires less monitoring vs continuous IV

• less potential for ADE vs bolus

• allows for increased stability vs bolus

• allows for intermittent high peak blood levels of drug

Intermittent IV disadvantages

• volume or concentration limits

• less constant blood levels vs continuous IV

• requires increased time for preparation/administration

• increased infection risk

Epidural

• space between verterbral column and the outermost meningeal membrane covering the spinal cord

• commonly utilized for analgesia and/or anesthesia

• decreases dose required with associated reduction of side effects

Epiural requirement

must be preservative free and have labeling for epidural use

Intrathecal (Subaracnoid)

intrathecal space is between the middle meningeal membrane covering the spinal cord and arachnoid membrane and inner meningeal membrane and contains cerebrospinal fluid

IV Vincristine requirements

• minibag of compatible solution

• never dispense and/or administer using a syringe

• prohibit in areas where intrathecal medications are administered and/or stored

• confirm that prescribed intrathecal medications have been administered before dispensing IV vincristine