test 2 Flashcards
Properties of drugs and models of dependence (73 cards)
what are pharmacodynamics?
they physiological actions of drugs
what are pharmacokinetics?
how drugs move through the body
what are the 4 stages of pharmacokinetics?
- absorption
- distribution
- biotransformation
- elimination
what are the routes of administration in order of fastest acting to slowest acting?
-intravenous
-inhalation
-insufflation
-intramuscular injection
-subcutaneous injection
-oral administration
what are the benefits of intravenous drug absorption? what are the risks?
-high concentrations can be delivered and there is no absorption limit
-veins may become damaged over time if the same injection site is used repeatedly and blood-borne diseases can spread
what happens in inhalation? what are the effects? what are the risks?
-the drug moves from the lungs into the bloodstream through the capillary walls
-rapid onset effects
-control of dose is difficult and lung toxicity
what happens in insufflation? how fast does it happen? what are the risks?
-absorption through the mucous membranes into the bloodstream
-within minutes
-nasal necrosis and hepatitis C (from sharing insufflation devices)
what is intramuscular injection? what are the benefits how is it useful?
-in a muscle
-absorption is more rapid due to greater blood supply in muscles
-useful with noncompliant patients
what is subcutaneous injection? what is the risk?
-under the skin
-can cause necrosis if the same injection site is used
how fast is oral administration?
relatively slow, 15-60 minutes
what must a drug go through when taken through oral administration?
-withstand digestive acid
-pass through the cells lining the gastrointestinal tract into the bloodstream (mostly in the small intestine)
-pass through the liver where they may be metabolized
why is oral administration used as the method for most over the counter and prescription medications?
it is the safest
-the stomach can be pumped in case of overdose
-some drug is broken down before it reaches the brain and the potential negative outcomes are reduced
what is distribution?
passage of the drug from the bloodstream to sites of action in the body
what is absorption?
drug being absorbed into the bloodstream and drug administration
what is bioavailibility?
the ability of a drug to reach a site of action (typically in the brain)
what is the blood-brain barrier?
barrier that surrounds the blood capillaries and vessels in the brain and prevents substances in blood from entering the brain
what is elimination?
process by which drug leaves the body; the goal is to produce a steady state of drug effects
what does the elimination rate determine? what is a half-life?
-how long the effects will last
-duration of time necessary for the body to eliminate half of the drug
how do drugs alter the availability of neurotransmitters during synthesis? what is an example?
-create the neurotransmitter molecule
-LDOPA for Parkinsons disease
how can drug affect neurotransmitter availability during storage in vesicles? what is an example?
- immediate release of neurotransmitters instead of storage in vesicles
-amphetamines, MDMA
what are examples of drugs that affect the availability of neurotransmitters during reuptake?
SSRIs and cocaine
how can drugs affect neurotransmitter availability during metabolism? what is an example?
-increase or decrease the enzyme that metabolize the neurotransmitter
-MAOI (monoamine oxidase inhibitor) antidepressants and acetylcholinesterase inhibitor for Alzheimer’s disease
what does an agonist do? what is an example?
-fully activates a receptor by sitting in and binding to a receptor site
-opiates (bind to endorphin receptors)
what does an antagonist do? what is an example?
-fails to activate receptor but bind to receptor site
- botox (blocks acetylcholine), naloxone (blocks opiate receptor sites and can displace opiate already bound to the receptor site), antipsychotics (block dopamine)