Parenteral Flashcards
What does parenteral mean?
par(a) = beside/outside enetral = intestine
what is parenteral administration?
- par(a) = beside
- enteral = intestine
- therefore any route that bypasses the intestine
What is the BP definition of parenteral administration?
sterile preparations for administration by injection, implantation, infusion into humans or animals
According to the BP, parenteral preparations must be sterile. What are two approaches to sterilisation and what do they need to ensure and avoid?
- aseptic preparation
- terminal sterilisation
- need to ensure sterility
- need to avoid contaminants
Why is parenteral administration useful? (5)
- can be used for drugs w low stability in GIT
- local administration - higher concs e.g. intra-ocular
- GIT may not be available
- rapid onset of action; emergencies (no additional step like with caps and tabs)
- achieving prolonged release (implants, IM)
What types of drugs is parenteral administration useful for? (2)
- those with low stability in the GI tract
- those which need prolonged release (implants, IM)
In what patient-related situations is parenteral administration useful?
- emergencies: due to rapid onset of action
- unconscious/dysphagia: makes GIT unavailable as patient cannot swallow
What are the 3 main routes of parenteral administration?
- intravenous (25 degrees)
- subcutaneous (45 degrees)
- intramuscular (90 degrees, deepest needle)
whats IV route of parenteral admin: administered into and used for?
veins inside dermin
used for allergy tests etc…
where is IM injected into?
deepest of the injections
90 degree angle
tissue layer under dermis
Apart from the 3 main routes, what are other routes of parenteral administration?
- intra-arterial
- intra-articular (joints)
- intra-synovial
- intracameral
- intracardiac
….
…
describe IV injection- how much and where admin?
Single dose
Continuous infusion: therefore control rate
Peripheral or central vein
IV volume administered- when is small vol used and when large?
Small (<10 mL)
Emergency
Large (>500 mL)
Fluid replacement
Nutrition
types of IV formulation examples
Aqueous:
- Solutions
- Emulsions
- Nanosuspensions not normal as bigger particles can embolise in small capillaries
routes of Intravenous administration? (2)
Peripheral vein
• Forearm/elbow
• Back of hand
Central vein
• Frequent access required
• Limited peripheral access
examples of intravenous administration
- Antibiotics (long term)
- Parenteral nutrition
- Chemotherapy
IV soln may be irritating. how can you avoid damaging peripheral veins?
can dilute, prevent pain and irritation
advantages of IV administration
- 100% bioav
- rapid onset of action
- rapid dilution in blood circ
- useful if drug too irritating for SC/IM
- self admin possible- e.g. PCA devices
- useful is no other routes available
disadvantages of parenteral administration (all)
- Invasive, inconvenient, restrictive
- Training required
- Strict sterility requirements
- Higher production costs
- Aseptic techniques required
- Risk for conversion errors
- Can be/is perceived as painful
- Management of waste (sharps)
- Formulation can be challenging
- Difficulty to self-administer
Subcutaneous administration: injection- where?
Fatty tissue under dermis
Upper arm
Anterior thigh
Lower abdomen
Proximity of capillaries
tissues-> caps -> blood circ -> lymphatic circs
Subcutaneous administration: volume- how much and mixed with what?
Small (1-2 mL) Large with: Divided doses Hypodermoclysis SC infusion Slow rate Palliative/hydration To be mixed with hyaluronidase: break down connective tissue
Subcutaneous administration types of formulation?
Aqueous solutions
Aqueous suspension
Oily solutions
Oily suspensions
Subcutaneous administration formulation and liposolubility impact on? (2)
Diffusion rate
Onset of action
use of hyaluronidase in SC preps?
benefit
Hyalase
mix w drug, : break down connective tissue
allow admin of larger volumes?