PED1003 PHARMACOLOGY EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
LATEST UPDATE
Pharmacology
The study of drugs and their interactions with living systems
Pharmacodynamics
The effects of a drug on the body
Study of this allows us to determine appropriate dose range for patients and
compare the effectiveness and safety of one drug to another
Pharmacokinetics
What the body does to the drug (absorption, distribution, metabolism,
excretion)
Study allows us to design and optimise treatment regimes for individuals,
e.g. deciding on route of administration, frequency of drug administration,
and duration of treatment
ADME
Absorption- from site of administration into blood
,Distribution- drug can reversibly leave bloodstream and distribute into
interstitial and intracellular fluids of tissues
Metabolism- body inactivates drug through enzymatic modification
Excretion- drug eliminated from body in urine, bile or faeces
Sources of drugs
Natural:
-Previous major source
-Plant material, etc.
-E.g. taxanes (anti-cancer agents) from yew tree bark
Synthetic;
-Current major source
-Either totally synthetic or identical/derived from natural compounds
-e.g. insulin (identical) or codeine (derived)
-Generally more advantageous due to degree of control
Biologics:
-New class
-e.g. manufactured hormones and growth factors
Drug interactions with targets
,Shape/conformation- determines ability of drug to bind (lock and key
mechanism therefore shape of drug similar to receptor)
Charge distribution- determines types of bonds holding drug to target
Hydrophobicity- how water soluble a drug is dictates where it goes in the
body
Ionisation of the drug (pKa)- dictates whether or not drug ionised at body pH,
has to be able to travel through different pHs
Stereochemistry- enantiomer forms can dictate whether or not the drug will
bind properly, e.g. thalidomide
Targets for drug action- receptors
-Targets for endogenous transmitters, e.g. hormones and neurotransmitters
-E.g. β2 adrenoreceptor acted on by salbutamol to treat asthma
Targets for drug action- ion channels
-Pores which span membranes to allow selective passage of ions
-e.g. voltage gated sodium ion channel acted on by lidocaine for use as local
anaesthetic
Targets for drug action- enzymes
, -Biological catalysts which facilitate biochemical reactions
-e.g. cyclooxygenase acted on by aspirin for use as an analgesic
Targets for drug action- carrier molecules
-Transport ions and small organic molecules across cell membranes
-e.g. proton pump acted on by omeprazole for use against ulcers
Example of antidote
Acetylcysteine- treats paracetamol poisoning
Example of antacid
Aluminium hydroxide
Example of laxative
Lactulose
Receptors and drugs
-Receptors are the sensing elements in the system of chemical
communications- coordinate function of all cells in the body
-Chemical communications are chemical messengers, e.g. hormones,
neurotransmitters, growth factors, etc.
-Drugs either mimic the action of these messengers (agonists) or block them
(antagonists)
Agonists
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
LATEST UPDATE
Pharmacology
The study of drugs and their interactions with living systems
Pharmacodynamics
The effects of a drug on the body
Study of this allows us to determine appropriate dose range for patients and
compare the effectiveness and safety of one drug to another
Pharmacokinetics
What the body does to the drug (absorption, distribution, metabolism,
excretion)
Study allows us to design and optimise treatment regimes for individuals,
e.g. deciding on route of administration, frequency of drug administration,
and duration of treatment
ADME
Absorption- from site of administration into blood
,Distribution- drug can reversibly leave bloodstream and distribute into
interstitial and intracellular fluids of tissues
Metabolism- body inactivates drug through enzymatic modification
Excretion- drug eliminated from body in urine, bile or faeces
Sources of drugs
Natural:
-Previous major source
-Plant material, etc.
-E.g. taxanes (anti-cancer agents) from yew tree bark
Synthetic;
-Current major source
-Either totally synthetic or identical/derived from natural compounds
-e.g. insulin (identical) or codeine (derived)
-Generally more advantageous due to degree of control
Biologics:
-New class
-e.g. manufactured hormones and growth factors
Drug interactions with targets
,Shape/conformation- determines ability of drug to bind (lock and key
mechanism therefore shape of drug similar to receptor)
Charge distribution- determines types of bonds holding drug to target
Hydrophobicity- how water soluble a drug is dictates where it goes in the
body
Ionisation of the drug (pKa)- dictates whether or not drug ionised at body pH,
has to be able to travel through different pHs
Stereochemistry- enantiomer forms can dictate whether or not the drug will
bind properly, e.g. thalidomide
Targets for drug action- receptors
-Targets for endogenous transmitters, e.g. hormones and neurotransmitters
-E.g. β2 adrenoreceptor acted on by salbutamol to treat asthma
Targets for drug action- ion channels
-Pores which span membranes to allow selective passage of ions
-e.g. voltage gated sodium ion channel acted on by lidocaine for use as local
anaesthetic
Targets for drug action- enzymes
, -Biological catalysts which facilitate biochemical reactions
-e.g. cyclooxygenase acted on by aspirin for use as an analgesic
Targets for drug action- carrier molecules
-Transport ions and small organic molecules across cell membranes
-e.g. proton pump acted on by omeprazole for use against ulcers
Example of antidote
Acetylcysteine- treats paracetamol poisoning
Example of antacid
Aluminium hydroxide
Example of laxative
Lactulose
Receptors and drugs
-Receptors are the sensing elements in the system of chemical
communications- coordinate function of all cells in the body
-Chemical communications are chemical messengers, e.g. hormones,
neurotransmitters, growth factors, etc.
-Drugs either mimic the action of these messengers (agonists) or block them
(antagonists)
Agonists
