PHM 431 EXAM REVIEW QUESTIONS
WITH COMPLETE ANSWERS
Describes how the action of a drug is time & space dependent - Answer-
pharmacokinetics
Routes of drug administration (2 major, 5 sub) - Answer-1. Enteral (via GI tract) -- oral &
sublingual
2. Parenteral (not via GI tract) -- intravenous, subcutaneous, intramuscular
Oral advantages (1) - Answer-easy & convenient for most drugs/patients
Oral disadvantages (4) - Answer-1. Time of onset of effect is slow & peak
concentrations are reduced due to the first pass effect (occurs b.c blood supply draining
the GI tract flows thru the liver which has lots of enzymes that metabolize/degrade
substances)
2. Morphine & heroin are victims to a large first pass effect, which limits their
effectiveness after oral administration
3. Difficult to achieve a high or stable plasma (blood) [ ]
4. Some drugs cannot be administered orally b.c they are poorly absorbed or easily
degraded in the acidic environment of the stomach
Sublingual -- what is it & examples? - Answer-Drugs taken as tablets held in the mouth
or under the tongue
ex: nitroglycerin for angina relief, nicotine chewing gum
Sublingual advantages (4) - Answer-1. No first pass effect b.c the liver is by-passed
2. Blood supply to mouth is good
3. Absorption is rapid
4. Oral pH is neutral & drugs may be more stable
Sublingual disadvantages (3) - Answer-1. Holding dose in mouth is inconvenient
2. Only small doses can be used
2. Erratic absorption/not well accepted
Intravenous (IV) advantages (3) - Answer-1. Drugs may be given into a peripheral vein
over 1 to 2 mins, maybe longer by infusion
2. Rapid onset of drug action (important for situations that require instantaneous drug
action--epileptic seizures, acute asthma attack, cardiac arrhythmias)
3. Whole dose is delivered to bloodstream, no first pass effect
Intravenous (IV) disadvantages (3) - Answer-1. Difficulty finding a vein, due to rapid
response
, 2. Toxicity can be an issue (all drugs can be toxic at high [ ], drug level needs to be
maintained in therapeutic window)
3. IV administration required trained personnel -- expensive & concern of sterility
Subcutaneous (s.c.) - Answer-administration of the drug dose just under the skin
Subcutaneous (s.c.) advantages (3) - Answer-1. Can be given by patient themselves
(e.g. insulin)
2. Slow absorption but usually complete -- slow release minimizes toxicity
3. Vasoconstrictor may be added to reduce absorption, thereby prolonging its effect at
injection site
Intramuscular (i.m.) advantages (2) - Answer-1. Slow release reduces toxicity
2. Depot/sustained release effect is possible, yielding longer duration of effect
Intramuscular (i.m.) disadvantages (2) - Answer-1. Trained personnel required
2. Injection site will influence absorption -- absorption sometimes erratic
All routes except _________ require drug passage thru the cytoplasm & membranes of
various cells to go into the _________ - Answer-IV, blood (circulation)
Process by which drug molecules reach the plasma from the original site of
administration - Answer-Absorption
Absorption rate depends on 3 things - Answer-1. Surface area of absorption surface
2. Vascularization of absorption surfaces
3. Blood flow to the site of absorption
Most common/important mechanism of drug absorption - Answer-Passive diffusion
Diffusion depends on... (3) - Answer-1. Ionization of drug molecules -- ionized
(polar/charged/hydrophilic) do not diffuse, while non-ionized (uncharged, lipophilic)
diffuse
2. Non-ionized drugs move down their concentration gradient across cell membranes;
net movement until equilibrium is reached
3. Small molecules cross more rapidly than large molecules
Drug dependence is associated with? - Answer-drug withdrawal
All drugs can create ____________, but not all drugs create ____________ - Answer-
dependence, addiction
Biological state that develops as result of tolerance to drug effects, involves a resetting
of mechanisms maintaining homeostasis - Answer-physical dependence
WITH COMPLETE ANSWERS
Describes how the action of a drug is time & space dependent - Answer-
pharmacokinetics
Routes of drug administration (2 major, 5 sub) - Answer-1. Enteral (via GI tract) -- oral &
sublingual
2. Parenteral (not via GI tract) -- intravenous, subcutaneous, intramuscular
Oral advantages (1) - Answer-easy & convenient for most drugs/patients
Oral disadvantages (4) - Answer-1. Time of onset of effect is slow & peak
concentrations are reduced due to the first pass effect (occurs b.c blood supply draining
the GI tract flows thru the liver which has lots of enzymes that metabolize/degrade
substances)
2. Morphine & heroin are victims to a large first pass effect, which limits their
effectiveness after oral administration
3. Difficult to achieve a high or stable plasma (blood) [ ]
4. Some drugs cannot be administered orally b.c they are poorly absorbed or easily
degraded in the acidic environment of the stomach
Sublingual -- what is it & examples? - Answer-Drugs taken as tablets held in the mouth
or under the tongue
ex: nitroglycerin for angina relief, nicotine chewing gum
Sublingual advantages (4) - Answer-1. No first pass effect b.c the liver is by-passed
2. Blood supply to mouth is good
3. Absorption is rapid
4. Oral pH is neutral & drugs may be more stable
Sublingual disadvantages (3) - Answer-1. Holding dose in mouth is inconvenient
2. Only small doses can be used
2. Erratic absorption/not well accepted
Intravenous (IV) advantages (3) - Answer-1. Drugs may be given into a peripheral vein
over 1 to 2 mins, maybe longer by infusion
2. Rapid onset of drug action (important for situations that require instantaneous drug
action--epileptic seizures, acute asthma attack, cardiac arrhythmias)
3. Whole dose is delivered to bloodstream, no first pass effect
Intravenous (IV) disadvantages (3) - Answer-1. Difficulty finding a vein, due to rapid
response
, 2. Toxicity can be an issue (all drugs can be toxic at high [ ], drug level needs to be
maintained in therapeutic window)
3. IV administration required trained personnel -- expensive & concern of sterility
Subcutaneous (s.c.) - Answer-administration of the drug dose just under the skin
Subcutaneous (s.c.) advantages (3) - Answer-1. Can be given by patient themselves
(e.g. insulin)
2. Slow absorption but usually complete -- slow release minimizes toxicity
3. Vasoconstrictor may be added to reduce absorption, thereby prolonging its effect at
injection site
Intramuscular (i.m.) advantages (2) - Answer-1. Slow release reduces toxicity
2. Depot/sustained release effect is possible, yielding longer duration of effect
Intramuscular (i.m.) disadvantages (2) - Answer-1. Trained personnel required
2. Injection site will influence absorption -- absorption sometimes erratic
All routes except _________ require drug passage thru the cytoplasm & membranes of
various cells to go into the _________ - Answer-IV, blood (circulation)
Process by which drug molecules reach the plasma from the original site of
administration - Answer-Absorption
Absorption rate depends on 3 things - Answer-1. Surface area of absorption surface
2. Vascularization of absorption surfaces
3. Blood flow to the site of absorption
Most common/important mechanism of drug absorption - Answer-Passive diffusion
Diffusion depends on... (3) - Answer-1. Ionization of drug molecules -- ionized
(polar/charged/hydrophilic) do not diffuse, while non-ionized (uncharged, lipophilic)
diffuse
2. Non-ionized drugs move down their concentration gradient across cell membranes;
net movement until equilibrium is reached
3. Small molecules cross more rapidly than large molecules
Drug dependence is associated with? - Answer-drug withdrawal
All drugs can create ____________, but not all drugs create ____________ - Answer-
dependence, addiction
Biological state that develops as result of tolerance to drug effects, involves a resetting
of mechanisms maintaining homeostasis - Answer-physical dependence
