routes of drug administration Flashcards
list several different routes of administration
Oral
Intravenous
Intra-arterial
Intramuscular
Subcutaneous
Inhalational
Topical
Sublingual
Rectal
Intrathecal
what is sublingual administration?
placing a drug under your tongue to dissolve and absorb into your blood through the tissue there.
what is Intrathecal administration?
injection into the subarachnoid space of the spinal cord.
This is a strategy to bypass the blood-brain barrier
what is subcutaneous administration?
a short needle is used to inject a drug into the tissue layer between the skin and the muscle.
Medication given this way is usually absorbed more slowly than if injected into a vein
suggest a route of administration for children?
lollipops
how long does intravenous administration take?
1 min - fastest
which route of administration has the highest bioavailability?
IV - 100%
what is PCA IV?
Patient controlled analgesia
patient presses a button every time they want more drug administered (IV)
what has a higher bioavailability - oral or IM administration?
IM injection has higher
roughly need double of oral quantities
how can you administer a drug to give steady concentrations?
slow release tablets
which route of administration has the most long term effect?
and it also has intermittent doses causing peaks and troughs
oral
define Bioavailability and how is it calculated?
how much a drug is available over a period of time.
Calculated using the area under the curve of a time-drug concentration graph
what factors affect rate of drug administration ?
gut motility - if you have slowed digestion
acidity - changes absorption
solubility
what quality of a drug determines if its ionised or unionised
determined by the pH of the drug
unionised drugs can get through more barriers
bypassing what increases the rate of absorption?
portal circulation
