Term
| Various routs of administration |
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Definition
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Term
| Different types of parenteral routes of administration |
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Definition
- intravenous
- intramuscular
- subcutaneous
- intrathecal
- inhalation
- transdermal (percutaneous)
Included all routes of admin EXCEPT GI TRACT |
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Term
| Different modes of enteral administration |
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Definition
- sublingual/buccal
- rectal
- oral
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Term
| Time course of various modes of adminstrations |
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Definition
- IV- starts in blood high and drops rapidly
- IM- peaks rapidly (highest peak) and drops
- subQ- slower rise than IM and gradual drop
- oral- slowest rise (lowest peak), and slowly drops
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Term
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Definition
- advantage
- rapid onset of action
- accurate control of blood levels
- directly to central compartment
- disadvantage
- non-removal
- rapid injection in high concentration that could produce toxic effects
- risk of:
- embolism
- fever
- excessive fluid loads
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Term
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Definition
- IM
- IM more rapid than subQ
- IM less sensitive to irritants than subQ
- subQ
- slow absorption if add with vasoconstrictor (ex: local anesthetics)
- sustained release preps available
- disadvantages
- pain
- irritation and local necrosis with subQ
- need to use small volumes with subQ
- infection, steril absesses
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Term
| Intrathecal effects and mechanism of action |
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Definition
- most drugs dont penetrate CNS (BBB)
- inflam. of meninges increase permeability of BBB
- for local effects and to circumvent barriers
- spinal anesthesia
- acute CNS infections
- brain tumors
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Term
| Adv./disadv. of inhalation |
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Definition
- adv.
- large surface area
- high blood flow
- efficient absorption of:
- gasses
- aerosols
- atomized particles
- local and systemic delivery
- equipment dependent- metered dose inhalers, aerosols
- disadv.
- allergic reactions
- route used for drugs of abuse and environmental toxins
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Term
| How does a particle have to be to get to trachea/bronchi? nose? alveoli |
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Definition
- alveoli- less than one micron
- trachea/bronchi- 2-5 microns
- nasal- 75 microns
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Term
| Mechanism of action/disadv. of percutaneous/transdermal |
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Definition
- Mechanism of action
- skin impermeable to most drugs
- dermis freely permeable to solutes
- more absorption through, abraded, denuded, or burned skin
- absorption dependent on surface area of application
- enhanced by oily suspension of drug
- hydrated skin is more permeable
- controlled release patches are more popular
- Disadvantages
- allergic reactions (esp. to adhesives used in the patch)
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Term
| Compare factors determining absorption in each enteral route |
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Definition
| factors determing absorption in GI are similar for each route |
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Term
| Anatomy of each enteral route |
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Definition
- buccal- blood drains into SVC
- oral- blood drains into portal circulation
- rectal- blood drains into portal circulation and pudendal veins
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Term
| Describe fate of drug going through buccal path and factors that are important in absorption |
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Definition
- place under tongue/btw cheek
- drain into SVC
- bypass liver and do not get immediate metabolism (NO FIRST PASS EFFECT)
- rapid onset
- lipid solubility and ionization are important factors as well
- weak acids absorbed better under acidic conditions
- weak bases absorbed better under more basic conditions
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Term
| Describe rectal route availablity, who its used for, absorption fate |
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Definition
- wide variety of drugs available
- useful for:
- unconscious patients
- children
- compounds that irritate stomach
- path- 50% of drug absorbed bypass liver
- absorption incomplete, irregular
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Term
| Adv./disadv. of oral route |
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Definition
- adv.
- most common
- economical
- safe
- sustained release prep
- disadv.
- irritate GI tract (nausea, vomitting, diarrhea)
- destroy drug via
- pH in stomach
- enzymes in GI tract (so dont give protein drug via this route)
- first pass effect (goes directly to liver via portal circulation)
- irregular absorption/slow onset
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Term
| Why is the small intestine the major site for absorption? |
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Definition
- surface area
- villi
- microvilli
- folds of Kercking
- transit time
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Term
| Describe pH gradient in duodenum and lower intestinal tract |
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Definition
- duodenum: pH = 4-5 (more acids absorb here)
- lower intestinal tract: pH = 5-7 (more bases absorb here)
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Term
| Role of stomach emptying rate and rate of absorption |
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Definition
- the faster the rate of stomach emptying, the faster absorption
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Term
| Clinical sign. of increased emptying rates? what substances empty faster |
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Definition
- fast emptying of:
- clinical significance
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Term
| Clinical significance of decreased rates of stomach emptying. Substances that tend to empty slower? |
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Definition
- substances like
- clinical significance
- labor
- abdominal trauma
- GI obstruction
- DM
- pneumonia
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Term
| Compare drug distribution of IV distrib. and rapidly perfused tissue? |
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Definition
- IV- starts high and declines
- rapidly perfused tissue- peak rapidly, then declines in levels at the same rate as IV
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Term
| Two factors that determine drug distribution |
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Definition
- blood flow (MAJOR)
- protein binding
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Term
| Major binding protein for drugs |
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Definition
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Term
| Describe structure/histology brain capillaries |
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Definition
- unlike systemic capillaries, contain tight juctions
- small pores
- line with perivascular glial cells
- only highly lipid soluble drugs pass into brain
SAME SYSTEM IN TESTES |
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Term
| Describe placental capillaries |
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Definition
- much more loose than systemic capillaries
- clinical sign.- if it is available orraly, fetus will be exposed
- normal cell membranes
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Term
| Describe breast milk composition |
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Definition
- pH: 6.8 (slightly acidic)
- exhibits ion trapping
- basic compounds tend to accumulate relative to blasma
- acidic compounts are present at lower concentrations relative to plasma
- neutral compounds (ex: ethanol) found in simliar concentration to mother's plasma
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