Final Pharmacology Flashcards
Which of the following statements most
accurately describes a system having
spare receptors?
• the number of spare receptors determines the maximum effect
• spare receptors are sequestered in the cytosol
• a single drug - receptor interaction results in many cellular response elements being activated
• spare receptors are active even in the absence of an agonist
• agonist affinity for spare receptors is less than their affinity for ‘non spare’ receptors
-A single drug- receptor interaction results in many cellular response elements being activated
In the presence of picrotoxin, diazepam is less efficacious at causing sedation, regardless of the dose. Picrotoxin by itself has no sedative effect even at the highest dose. Which of the following is correct?
• picrotoxin is a competitive antagonist
•diazepam is a full agonist and picrotoxin is a partial agonist
• diazepam is less efficacious than is picrotoxin • diazepam is less potent than is picrotoxin
• picrotoxin is a non competitive antagonist
-Picrotoxin is a non competitive anatoginst
In the presence of pentazocine, a higher concentration of morphine is required to elicit full pain relief. Pentazocine by itself has a smaller analgesic side effect than does morphine, even at the highest dose. Which of the following is correct regarding these medications?
• pentazocine is a competitive antagonist
• morphine is a full agonist and pentazocine is a partial agonist
• morphine is less efficacious than is pentazocine
• morphine is less potent than is pentazocine
• pentazocine is a non competitive antagonist
-Morphine is a full agonist and pentazocine is a partial agonist
If 10 mg of morphine produces a greater analgesic response than can be achieved by ibuprofen at any dose, which of the following statements is correct?
• morphine is less efficacious than is ibuprofen
• morphine is less potent than is ibuprofen
• morphine is a full agonist and ibuprofen is a partial agonist
• ibuprofen is a competitive antagonist
• morphine is a better drug to take for pain relief than is ibuprofen
-morphine is a better drug to take for pain relief than is ibuprofen
If 10 mg of naproxen produces the same analgesic response as 100 mg of ibuprofen, which of the following statements is correct?
• naproxen is more efficacious than is ibuprofen
• naproxen is more potent than ibuprofen
• naproxen is a full agonist and ibuprofen is a partial agonist
• naproxen is a competitive antagonist
• naproxen is a better drug to take for pain relief than is ibuprofen
-naproxen is more potent than ibuprofen
Isoproterenol produces maximal contraction of cardiac muscle in a manner similar to epinephrine. Which of the following best describes isoproterenol?
• full agonist
• partial agonist
• competitive antagonist • irreversible antagonist • inverse agonist
-FULL AGONIST
A drug with a half-life of 10 hours is administered by continuous intravenous infusion. Which of the following best approximates the time for the drug to reach steady state?
• 10 hours • 20 hours • 33 hours • 40 hours • 60 hours
-40 hours
Which of the following types of drugs will have maximum oral bioavailability?
• drugs with high first-pass metabolism
• highly hydrophilic drugs
• largely hydrophobic, yet soluble in aqueous solutions • chemically unstable drugs
• drugs that are P-glycoprotein substrates
-Largely hydrophobic, yet soluble in aqueous solutions
Chlorothiazide is a weakly acidic drug with a pKa of 6.5. If administered orally, at which of the following sites
of absorption will the drug be able to readily pass through the membrane?
• mouth (pH approximately 7.0)
• stomach (pH of 2.5)
• duodenum (pH approximately 6.1) • jejunum (pH approximately 8.0)
• ileum (pH approximately 7.0)
Chlorothiazide is a weakly acidic drug with a pKa of 6.5. If administered orally, at which of the following sites
of absorption will the drug be able to readily pass through the membrane?
• mouth (pH approximately 7.0)
• stomach (pH of 2.5)
• duodenum (pH approximately 6.1) • jejunum (pH approximately 8.0)
• ileum (pH approximately 7.0)
-Stomach (pH 2,5)
An 18-year-old female patient is brought to the emergency department due to drug overdose. Which of the following routes of administration is the most desirable for administering the antidote for the drug overdose?
• intramuscular • subcutaneous • transdermal
• oral
• intravenous
-intravenous
Select true statement(s)?
• if the efficacy of the drug is higher, the potency is higher as well
• if 10 mg of drug A produces the same response as 100 mg of drug B, drug A has a higher dose-response efficacy than drug B
• if 10 mg of drug A produces the same response as 100 mg of drug B, drug A has a higher clinical efficacy than drug B
• if 10 mg of drug A produces the same response as 100 mg of drug B, drug A has a higher potency than drug B
• variation in response to a drug among different individuals is most likely to occur with a drug showing a large therapeutic index
• a competitive antagonist increases the ED50
• in selecting a drug, potency is usually more important than efficacy
- if 10 mg of drug A produces the same response as 100 mg of drug B, drug A has a higher potency than drug B
- a competitive antagonist increases the ED 50
55 year old patient took diazepam daily to relieve severe anxiety. Initially, 5 mg dose produced a satisfactory response. After a few weeks his physician reported, that the same dose is not effective anymore. After an increase of the dose to 10 mg, the patient had the same relief of anxiety as taking 5 mg in the beginning of the treatment. What phenomenon has the physician reported? What are the mechanisms of this phenomenon? What happened with the potency and efficacy of diazepam?
• potency of diazepam increased
• efficacy of diazepam didn’t change
• efficacy of diazepam decreased
• the physician reported withdrawal • potency of diazepam decreased • the physician reported dependance • efficacy of diazepam increased
• the physician reported tolerance
- efficacy of it don’t change
- petency of diazepam decreases
- the physician should report tolerance
Insulin acts at an extracellular domain of a membrane spanning tyrosine kinase and causes its phosphorylation. Afterwards, tyrosine kinase activates intracellular enzymes responsible for glucose catabolism. Tyrosine kinase belongs to which family of receptors?
• enzyme linked receptors
• spare receptors
• G protein coupled receptors • ligand gated ion channels
• intracellular receptors
-enzyme-linked receptors
What pharmacological antagonists form irreversible covalent bonds on the agonist receptor site? • allosteric modulators • partial agonists • non-competitive antagonist • competitive antagonist • full agonists • inverse agonists
.non-compatative antagonist
What receptors have only hydrophobic ligands?
• intracellular receptors
• spare receptors
• G protein coupled receptors • enzyme linked receptors
• ligand gated ion channels
-intracellular
What antagonists decrease the potency of
an agonist, but have no effect on its efficacy
even in the absence of ‘spare’ receptors?
• competitive antagonists
• full agonists
• partial agonists
• inverse agonists
• non-competitive antagonist • allosteric modulators
-competetive antagonist
What ligands do not bind to the agonist receptor site, but bind to some other region of the receptor and change the response to an agonist?
• competitive antagonists • full agonists
• allosteric modulators • partial agonists
• inverse agonists
• non-competitive antagonists
-allosteric modulators
Heparin acts on antithrombin III and inhibits the coagulation cascade. Protamine sulphate doesn’t act on antithrombin III, but it binds to heparin and inactivates it instead. What kind of interaction occurs between heparin and protamine sulphate?
• pharmacological antagonism
• allosteric modulation
• pharmacological agonism
• physical / chemical antagonism • physiological agonism
• physiological antagonism
-physical/chemical antagonism
Histamine acts on histamine receptors and causes bronchial spasm in susceptible individuals. β adrenergic agonist albuterol causes bronchial dilation and relieves bronchial spasm. What kind of interaction occurs between histamine and albuterol? • physiological antagonism • physiological agonism • allosteric modulation • pharmacological agonism • pharmacological antagonism • physical / chemical antagonism
-physiological antagonism
Pindolol increases the heart rate by activating β adrenergic
receptors in the absence of epinephrine and other β
adrenergic agonists. However, it decreases the heart rate in
the presence of epinephrine. What kind of ligand is pindolol? • allosteric modulator
• full agonist
• partial agonist
• inverse agonist
• antagonist
• non-competitive antagonist • competitive antagonist
-partial agonist
Upon binding to α1-adrenoceptors on the membrane of vascular
smooth muscle, phenylephrine metabolises intracellular Ca2+,
causing the contraction of actin and myosin filaments. The
shortening of muscle cells decreases the diameter of the arteriole,
causing an increase in resistance to the flow of blood through the
vessel. Blood pressure therefore rises to maintain blood flow. All the
effects resemble the action of the endogenous ligand, • allosteric modulator
norepinephrine. What kind of ligand is phenylephrine? • antagonist
• full agonist
• non-competitive antagonist • partial agonist
• inverse agonist
-full agonist
Which of the following would up-regulate
postsynaptic β1 adrenergic receptors?
• daily use of amphetamine that causes norepinephrine to be released
•a disease that causes an increase in the activity of norepinephrine neurones
• daily use of isoproterenol, a β1 receptor agonist
• daily use of formoterol, a β1 receptor agonist
• daily use of propranolol, a β1 receptor antagonist
-daily use of propranolol, a β1 receptor antagonist
What impact on steady state concentration has doubling of the loading dose?
- decrease
- increase
- no change
-no CHANGE
The addition of glucuronic acid to the drug is what phase of reaction?
-phase 2
What will happen to the blood concentration of drug, soon after intravenous injection, if distribution into tissue is increased?
-it will decrease
The octanol/water partition coefficients of a drug is 10. IT DOES NOT BIND TO THE blood proteins. into which tissue the drug will distribute.
- lung
- muscle
- skin
-lung
Following oral administration of a lung, 100% of the dose is recovered as uncharged drug in the urine. Does this indicate that the entire dose was absorbed?
yes, true
A patient is treated with 250 mg of phenytoin per day. He reaches a concentration of 25 mg/l and therefore Will experience toxicity due to phenytoin.
Is it true?
false
Phenytoin is a drug of choice in the treatment of epilepsy. It has a narrow therapeutic window with concentration between 10 and 20 mg/l being associated with control of seizures. Three subjects A, B and C are treated with 200 mg of phenytoin per day, the normal dose calculated to control seizures with the minimum of side effects. All three subjects will therefore achieve concentrations within 10-20 mg/l range. Is it true?
no, false
A patient is treated with 150 mg of phenytoin per day. He achieves a concentration of 8 mg/l and may not require an increase in dose. Is it true?
true
In which site do drug interactions occur most commonly?
LIVER
Explain half-life.
-to remove half of the dose from plasma is half-life
What happens if the rate of infusion increases (i.e. higher amount of the drug administered per unit of time)?
-less time will be needed to reach steady state
