Parenterals Flashcards
Parenteral
- Intended to be placed in direct contact with the internal body fluids or tissues (injections)
- Must be sterile and pyrogen-free
Sterile
Absence of viable microorganisms
Sterilization
Process by which all viable microorganisms are removed or destroyed
Pyrogens
- Bacterial endotoxins
- Organic substances resulting microbial growth or breakdown
- Produces fevers, chills, malaise, shock when injected into humans
Injectables
Any dosage form placed beneath the skin of the body using a needle, catheter, or cannula
Thrombus
Blood clot formed within a blood vessel
Embolus
Thrombus that is circulating in blood stream
Embolism
Embolus lodges in a blood vessel and blocks or occludes blood flow
When to Use Parenterals
- Rapid onset of action (general)
- Patient is uncooperative
- Patient is unconscious
- Drug not absorbed through biological membranes (compare oral tablets)
Routes of Parenteral Administration
- Intramuscular - 90 degrees
- Subcutaneous - 45 degrees (subcutaneous tissue)
- Intravenous - 25 degrees (dermis)
- Intradermal - 10-15 degrees (epidermis)
IV Advantages
- Rapid onset of action - no absorption step
- Accurate blood levels can be achieved and maintained by continuous infusion of drug
- Useful in emergency situations because of the rapid circulation of the drug
IV Disadvantages
- Once administered, drug cannot be retrieved
- Potential for thrombosis or embolism - most common if needle touches wall of vein
- More common when drug solution is irritating to body tissue
Bevel
- Inject with needle facing upwards at an angle
- Ensure direction of flow is in flow with the blood
- Ensure that lumen is unobstructed
Flashback/Back Flow
Pulling back on syringe to ensure entrance into vein, blood should enter syringe if in vein
Aseptic Precaution
- Used to avoid risk of infection
- IV solution, syringe, and needle are sterile
- Swab skin area to clean prior to injection
Vessels
- Differ in size and closeness to surface
- Differ with age, type of illness, gender
- Men’s are closer to surface than womens’
Are injections more or less painful near fingers?
More
Should you administer irritating drugs in larger or smaller veins?
Larger - want the maximum chance of immediate dilution
What can be administered by IV?
- Large and small volume parenterals (no volume restriction)
- Drugs must be in solution - water or water-miscible solvent, emulsions (NO SUSPENSIONS OR OIL SOLUTIONS)
- Can use almost any size needle depending on injection site
IM Advantages
-Prolonged drug action compared to IV (depot effect)
IM Disadvantages
- Longer/larger needles needed
- Less rapid onset
- Absorption steps - muscle to blood stream which can be fast or slow depending on formulation
IM Route - Sites
- Avoid major nerves and blood vessels
- Upper quadrant of butt
- Thigh (vastus lateralis) or deltoid of arm are also good sites
- Thigh or deltoid are best for infants/small children (not enough muscle in gluteus maximus)
Should there be flashback/backflow of blood with IM?
No
What can be administered by IM?
- Aqueous solutions/suspensions
- Oleaginous solutions/suspensions
- Chemical/physical properties of drug and anticipated biological response determines which prep to use
- Solutions with water-miscible solvents are rarely used IM since they tend to cause irritation/damage
- Volume restrictions - 2 mL for deltoid; 5 mL for butt
SC Info
- Injection just under skin - loose interstitial tissue of upper arm, anterior thigh, or lower abdomen
- Shorter, more narrow gauge needles used
- No flashback/backflow
- Absorption step - rates can be rapid depending on formulation
- Aqueous solutions and suspensions
- Volume restriction - ~1.3 mL
ID (Intradermal) Info
- Injection just beneath epidermis
- Least common
- Typically for immunizations, diagnostics (TB), or anesthetics for pain during stitching procedures
- Short needles or narrow gauges
- VERY small injection volumes
ID Sites
- Upper pectorals
- Back near shoulder blades
- In the bends of elbows
Other Routes of Admin
- Intra-articular (joints)
- Intrasynovial (joint fluid area)
- Intraspinal (spinal column)
- Intrathercal (spincal fluid)
- Intra-arterial (arteries)
- Intracardiac (heart)
- Central venous catheters (ports) - used when repeated IVs are required like in chemo patients or TPN solutions
Parenteral Formulaiton Requirements
- Solvents/vehicles must be of highest purity
- Added substances must be of highest purity
- Inclusion of each material MUST be justified
- ALWAYS sterile and pyrogen-free
- Stricter compendial standards for the limits of particulate matter
- Prepared STRICTLY in controlled environments by trained personnel
- Packaged in HERMETICALLY sealed containers of high quality
- Filled to a volume that is in excess of the labeled size
- Restrictions limit the volume of the product which can be sealed into a container
- Specific label requirements
Parenteral Solvent Vehicles
Aqueous Vehicles
- Water for injection
- Sterile water for injection
- Bacteriostatic water for injection
- Sodium chloride injection
- Bacteriostatic sodium chloride injection
- Ringer and lactated ringer injected
Non-Aqueous Vehicles
Water for Injection, USP
- Purified by distillation or reverse osmosis
- Total solids <1mg/100 mL
- May contain added substances
- Must be pyrogen-free (not required to be sterile)
- Intended to be used in the manufacture or injectable products`
Sterile Water for Injection, USP
- Packaged in single-dose containers, no larger than 1 L
- Must be pyrogen-free (and sterile)
- Cannot contain any antimicrobial agents or other substances
- Intended to be used a solvent, vehicle, or diluent for already sterilized and packaged injectables
- 1 L bottle cannot be administered intravenously due to lack of ISOTONICITY
Bacteriostatic Water for Injection, USP
- Sterile water for injection containing one or more antimicrobial agents
- Packaged in prefilled syringes or vials (=< 30 mL)
- Used as a sterile vehicle in preparation of small volume parenterals (< 5mL of solvent is needed)
- Labeled “not for use in neonates”