Parenteral routes Flashcards
what are the requirements of parenteral route manufacture
- must be manufactured to high standards
- sterile
- pyrogen free (don’t produce what in body)
- microbial by-products such as endotoxins - no particulates (glass, fibres, floaters, precipitates)
- containers- transparent
outline the reasons for when an injectable would be used
- rapid drug action required/anaphalaxis
- Patient uncooperative, unconscious or unable to tolerate oral medications (vomiting)
- drug ineffective by other routes
- poorly absorbed, inactivated, irritant - local action- eg. local anaesthetic at dentist surgery
- prolonged action required- eg goserelin (zoladex) implant (28 days and 12 weeks)
what are the problems with injectables
- once administered, generally can’t remove (overdose, side effects)
- more difficult and expensive to produce (sterile, pyrogen free, particulate free)
- poor compliance- pain, discomfort, inconvenience
- can require trained personnel (IV, IM)
name the 2 types of injection
- small volume parenterals
- large volume parenterals
what are small volume parenterals
- 1-50ml
- not necessarily administered IV
- not necessarily isotonic
- not necessarily at physiological pH (7.4)
what are large volume parenterals
- up to 1000ml
- IV infusion over prolonged period
- isotonic (0.9% NaCl or 5% dextrose)
what is meant by hypertonic
A hypertonic solution has increased solute, and a net movement of water outside causing the cell to shrink
- reversible
what is meant by hypotonic
A hypotonic solution has decreased solute concentration, and a net movement of water inside the cell, causing swelling and eventually burst
-irreversible damage
what are the 3 types of injectable
- sterile solution
- solvent can be water/vegetable oil (IM only) - sterile suspensions (IM) and emulsions (IV)
- continuous phase can be water or oil - implants
- subcutaneous or IM
List the different routes of parenteral delivery
- intravenous (small or large volumes)
- subcutaenous or hypodermic (up to 2ml)
- intramuscular (2.5ml, greater than 5ml in divided doses)
- intradermal or intracutaneous (0.1ml)
- interarticular- joints
- intrasynovial- joint fluid area
- intraspinal- spinal column
- intrathecal- spinal fluid
- intra-arterial- arteries
- intracardiac- heart
explain how methylprednisolone acetate is administrated
- intra-articular injection (aqueous suspension) 40mg/ml
- dose 4-80mg, where appropriate may be repeated at intervals of 7-35 days
- also IM
What does the IV route consist of
- veins of forearms
- small volume (bolus)
- large volume infusions
- set at appropriate rate
- generally aqueous solutions
what are the uses of the IV route
- emergencies- bolus delivery (drug toxicity and irritation)
- fluid, electrolyte supplements- shock, severe bleeding, dehydration
- nutrient supplements- comatose patients
name the types of IV administration
- IV bolus or IV push
- intermittent infusion
- continuous infusion
what is an IV bolus or IV push
1-2ml, over seconds to a few minutes and can be repeated at intervals
what is an intermittent infusion
drug is diluted in 25-100ml fluid and infused over 15-60 minutes at spaced intervals
what is a continuous infusion
drug is added to Large volume parenterals (up to 1000ml) and slowly and continuously infused