NR293 Exam 1 Review
PHARMACOLOGY
,Chapter 2: pharm principles
• Pharmacokinetics:
• Absorption
• Oral meds go through the first pass effect
• IV meds are immediately available for use at the cellular/tissue level: Faster than oral route
• Distribution
• Drug being disturbed throughout the body
• Requires stable cardiovascular system
• Metabolism
• Drug either activated, decreased activity, or totally inactivated
• Primary drug is Liver
• Decrease in liver function= decrease in metabolism, which may increase risk of toxicity
• Excretion
• Drug leaving the body
• Primary organ is the kidneys
• Decrease in renal function= decrease in elimination of drug: if drug is still active, increases risk of toxicity
, Half-life
• Time it takes for ½ of drug to be elimated from the body
• 5 half-lives lead to steady state
• 5 half-lives eliminate 97% of drug
• Example: At 8 am: drug A has a serum level of 400 mg/dl and the half-life is 8
hours.
• 1st half-life 4 pm drug level is 200
• 2nd half-life 12 amdrug level is 100
• 3rd half-life 8 am drug level is 50
• 4th half-life 4 pm drug level is 25
• 5th half-life 12 amdrug level is 12.5 (approx. 97% drug is now gone)
, Drug terms
• Therapeutic Index
• Safety of drug
• Low or narrow- difference between the therapeutic dose and a toxic dose is small: more risk of toxicity/drug
reaction
• High therapeutic index- difference between therapeutic dose and toxic dose is wide: safer drug
• Agonist
• Drug binds to and stimulates one or more receptor sites in the body
• Antagonist
• Drug that binds to and inhibits the activity of one or more receptors
• Also called an inhibitor
• Partial agonist
• Drug binds to and partially stimulates one or more receptor sites in the body
PHARMACOLOGY
,Chapter 2: pharm principles
• Pharmacokinetics:
• Absorption
• Oral meds go through the first pass effect
• IV meds are immediately available for use at the cellular/tissue level: Faster than oral route
• Distribution
• Drug being disturbed throughout the body
• Requires stable cardiovascular system
• Metabolism
• Drug either activated, decreased activity, or totally inactivated
• Primary drug is Liver
• Decrease in liver function= decrease in metabolism, which may increase risk of toxicity
• Excretion
• Drug leaving the body
• Primary organ is the kidneys
• Decrease in renal function= decrease in elimination of drug: if drug is still active, increases risk of toxicity
, Half-life
• Time it takes for ½ of drug to be elimated from the body
• 5 half-lives lead to steady state
• 5 half-lives eliminate 97% of drug
• Example: At 8 am: drug A has a serum level of 400 mg/dl and the half-life is 8
hours.
• 1st half-life 4 pm drug level is 200
• 2nd half-life 12 amdrug level is 100
• 3rd half-life 8 am drug level is 50
• 4th half-life 4 pm drug level is 25
• 5th half-life 12 amdrug level is 12.5 (approx. 97% drug is now gone)
, Drug terms
• Therapeutic Index
• Safety of drug
• Low or narrow- difference between the therapeutic dose and a toxic dose is small: more risk of toxicity/drug
reaction
• High therapeutic index- difference between therapeutic dose and toxic dose is wide: safer drug
• Agonist
• Drug binds to and stimulates one or more receptor sites in the body
• Antagonist
• Drug that binds to and inhibits the activity of one or more receptors
• Also called an inhibitor
• Partial agonist
• Drug binds to and partially stimulates one or more receptor sites in the body
