Pharmacology for Midwifery Students (NZ)
UPDATED Questions with CORRECT
Answers
1.Define Pharmacodynamics - CORRECT ANSWER - The effect of the drug on the body,
including the mechanism of action, effect, side effects.
2.What is a ligand? - CORRECT ANSWER - A molecule that binds to a receptor - can be
an agonist or antagonist.
3.What is the difference between an agonist and an antagonist? - CORRECT ANSWER -
Agonists bind to receptors causing cellular effects/actions. Can be partial or full agonist. Partial
agonists can only ellicit a portion of the effect/action of the receptor it binds to.
Antagonists block the effects of agonists. Competitive antagonists bind to the same sites as
agonists preventing agonists from binding there and having their effect. Non-competitive
antagonists act in some other way to block agonist effects.
4.Give 2 examples of an agonist, its receptor and its antagonist. - CORRECT ANSWER -
Pethidine: Mu opioid receptors (G-protein coupled receptors), Naloxone is its competitive
antagonist.
Adrenaline: Beta 1 adrenergic receptors (G-protein coupled receptors), Beta blockers e.g.
Metoprolol.
Syntocinon: Oxytocin receptors (G-protein coupled receptors on myometrium), Atosiban is its
competitive antagonist.
5.Name and briefly define the four types of protein molecules that can be acted on by drugs to
exert a pharmacological effect? Give an example of each of these types of protein molecule and a
drug that acts upon each of them. - CORRECT ANSWER - Receptors are any functional
macromolecule in a cell to which a ligand binds to produce its effect.
Ion channels: ligand cause membrane to morph/change shape to open an ion channel e.g. local
anaesthetic blocks Na+/Sodium channels so action potentials cannot be sent.
, Steroid receptors: actication regulates gene expression altering protein synthesis, e.g. sex
hormones like oestrogen in pill.
Enzyme-linked receptors: a ligand triggers production of enzymes that have an effect, e.g.
NSAIDS are inhibitors of cyclooxygenase (COX).
G-protein coupled receptors: a 2 part receptor - receptor, G-protein and effector. Receptor
switches on intracellular enzymes that make 2nd messengers that have cellular effects, e.g.
Adrenaline acts on B1 G-protein coupled receptors, makes second messenger cAMP and send it
out via effector on cell surface.
6.What is the difference between efficacy and affinity? How are these terms related but different
to potency? - CORRECT ANSWER - Efficacy = how strong the effect/response to the
drug is.
Affinity = how well a drug binds to receptors.
Potency = amount of drug required to produce half the desired effect. Potency is increased by
higher affinity and higher efficacy - the are both factors in potency.
7.Explain the concept of de-sensitisation and tolerance. What is the difference between the two
terms? - CORRECT ANSWER - Both refer to a decrease in a drug's effect over time. De-
sensitisation happens rapidly - over minutes. Tolerance happens over long-term e.g. by down-
regulation - reducing the number of receptors on the surface of target cells.
8.Define the term Pharmacokinetics. What is the difference to Pharmacodynamics? - CORRECT
ANSWER - The drugs movement throughout the body including how it reaches and leaves
its site of action and at what concentration.
9.Name commonly used routes of administration. Think about barriers to absorption, absorption
pattern, advantages and disadvantages for each way of administration. - CORRECT
ANSWER - Oral or enteral
Parenteral
Inhalation
Topical (e.g. local therapy of the skin, eyes, ears, nose, mouth or vagina)
Rectal
Vaginal
UPDATED Questions with CORRECT
Answers
1.Define Pharmacodynamics - CORRECT ANSWER - The effect of the drug on the body,
including the mechanism of action, effect, side effects.
2.What is a ligand? - CORRECT ANSWER - A molecule that binds to a receptor - can be
an agonist or antagonist.
3.What is the difference between an agonist and an antagonist? - CORRECT ANSWER -
Agonists bind to receptors causing cellular effects/actions. Can be partial or full agonist. Partial
agonists can only ellicit a portion of the effect/action of the receptor it binds to.
Antagonists block the effects of agonists. Competitive antagonists bind to the same sites as
agonists preventing agonists from binding there and having their effect. Non-competitive
antagonists act in some other way to block agonist effects.
4.Give 2 examples of an agonist, its receptor and its antagonist. - CORRECT ANSWER -
Pethidine: Mu opioid receptors (G-protein coupled receptors), Naloxone is its competitive
antagonist.
Adrenaline: Beta 1 adrenergic receptors (G-protein coupled receptors), Beta blockers e.g.
Metoprolol.
Syntocinon: Oxytocin receptors (G-protein coupled receptors on myometrium), Atosiban is its
competitive antagonist.
5.Name and briefly define the four types of protein molecules that can be acted on by drugs to
exert a pharmacological effect? Give an example of each of these types of protein molecule and a
drug that acts upon each of them. - CORRECT ANSWER - Receptors are any functional
macromolecule in a cell to which a ligand binds to produce its effect.
Ion channels: ligand cause membrane to morph/change shape to open an ion channel e.g. local
anaesthetic blocks Na+/Sodium channels so action potentials cannot be sent.
, Steroid receptors: actication regulates gene expression altering protein synthesis, e.g. sex
hormones like oestrogen in pill.
Enzyme-linked receptors: a ligand triggers production of enzymes that have an effect, e.g.
NSAIDS are inhibitors of cyclooxygenase (COX).
G-protein coupled receptors: a 2 part receptor - receptor, G-protein and effector. Receptor
switches on intracellular enzymes that make 2nd messengers that have cellular effects, e.g.
Adrenaline acts on B1 G-protein coupled receptors, makes second messenger cAMP and send it
out via effector on cell surface.
6.What is the difference between efficacy and affinity? How are these terms related but different
to potency? - CORRECT ANSWER - Efficacy = how strong the effect/response to the
drug is.
Affinity = how well a drug binds to receptors.
Potency = amount of drug required to produce half the desired effect. Potency is increased by
higher affinity and higher efficacy - the are both factors in potency.
7.Explain the concept of de-sensitisation and tolerance. What is the difference between the two
terms? - CORRECT ANSWER - Both refer to a decrease in a drug's effect over time. De-
sensitisation happens rapidly - over minutes. Tolerance happens over long-term e.g. by down-
regulation - reducing the number of receptors on the surface of target cells.
8.Define the term Pharmacokinetics. What is the difference to Pharmacodynamics? - CORRECT
ANSWER - The drugs movement throughout the body including how it reaches and leaves
its site of action and at what concentration.
9.Name commonly used routes of administration. Think about barriers to absorption, absorption
pattern, advantages and disadvantages for each way of administration. - CORRECT
ANSWER - Oral or enteral
Parenteral
Inhalation
Topical (e.g. local therapy of the skin, eyes, ears, nose, mouth or vagina)
Rectal
Vaginal
