pharm & toxico lec 1-7

Rachael_Dias

The concentration value of a drug required to occupy 50% of its receptor site is:

a. The concentration required to produce the maximum physiological effect

b. Directly proportional to the drugs affinity for its receptor

c. Inversely proportional to the drugs affinity for its receptor

d. Directly proportional to the drugs intrinsic efficacy

e. Usually determined from some obscure equation

c. Inversely proportional to the drugs affinity for its receptor

A partial agonist is typically a drug that:

a. Has low affinity for its receptor

b. Can only occupy a small fraction of its receptors

c. Can only produce a sub maximal response

d. Requires high doses to produce a maximal response

e. Increases the number of spare receptors

c. Can only produce a sub maximal response

Receptor desensitization can result from:

a. Binding to an antagonist

b. Exposure to an inverse agonist

c. Irreversible agonist binding

d. Spare receptors

e. Phosphorylation of receptors protein

e. Phosphorylation of receptors protein

Which second messenger in a g protein coupled receptor signalled transduction cascade typically increases intracellular calcium released from SR

a. Cyclic GMP

b. Cyclic amp

c. Diasyglycerol

d. Arachidonic acid

e. Ip3

e. Ip3

The metabolic precursor for noradrenaline is:

a. Adenosine

b. L-tyrosine

c. Nothing

d. Arginine

e. Both a and b

b. L-tyrosine

Coupling of a g protein alpha subunit to an agonist occupied receptor initially leads to:

a. Activation of the beta gamma complex

b. Hydrolysis of GTP

c. Activation of adenylate cyclase

d. Exchange of bound GDP with GTP

e. Disassociation of the alpha subunit from the receptor

d. Exchange of bound GDP with GTP

The opening of chloride ion channels by gamma amino butyric acid is facilitated by:

a. Tricyclic antidepressant drug

b. Benzodiazopiens

c. Local anthesiaics

d. Opiate analgesics

e. Central nervous system

b. Benzodiazopiens

Which type of receptor contain 7 transmembrane helices:

a. Nicotinic AR

b. Sodium channels

c. Steroid hormone receptors

d. Insulin receptors

e. GPCR

e. GPCR

Which receptors are entirely located intracellular

a. GPCR

b. Nicotinic receptors

c. Hormone receptors

d. Cytokine and growth factor receptors

e. Muscarinic receptors

d. Cytokine and growth factor receptors

The most rapid response is produced by:

a. Kinase linked receptors

b. GPCR

c. Receptors activating gene transcription

d. Ligand gated ion channels

e. Insulin receptors

d. Ligand gated ion channels

In smooth muscle inositol triphosphate release calcium from the:

a. Golgi body

b. Mitochondria

c. Cell nucleus

d. T tubule

e. Sarcoplasmic reticulum

e. Sarcoplasmic reticulum

Concerning the effect of pH on the urinary excretion of drugs it can be correctly stated that

a. Urinary acidification accelerates excretion of weak acids and bases

b. Urinary alkalisation accelerates excretion of weak acids and bases

c. Urinary acidification accelerates excretion of weak acids

d. Urinary alkalization accelerates excretion of weak acids

e. Urinary alkalization has no effect on excretion of weak bases

d. Urinary alkalization accelerates excretion of weak acids

A calculated volume of distribution greater than total body water is most likely to occur with

drugs that are:

a. Highly ionized

b. Highly lipid soluble

c. Subject to a high degree of first pass in activation

d. Highly bound to plasma proteins

e. Very large molecules

b. Highly lipid soluble

The binding of drugs to plasma albumin:

a. Is usually irreversible

b. Shows characteristics of saturation

c. Is most important for basic drugs

d. Accelerates drug metabolism

e. Accelerates drug excretion

b. Shows characteristics of saturation

Drugs that can cross the plasma membrane are generally

a. A weak base

b. Protonated

c. Polar

d. Uncharged

e. B and D

d. Uncharged

Drugs that are weak acids

a. Are not absorbed well into the blood stream

b. Are generally in protonated form

c. Tend to accumulate in areas of high pH

d. Tend to accumulate in areas of low pH

e. None of the above

c. Tend to accumulate in areas of high pH

A Receptor is

a. A target that can combine to a drug to elicit an effect

b. A protein that is activated by agonist to produce a physiological response

c. Either and ion channel or GPCR

d. A protein that binds to ligand

e. Both a and b

b. A protein that is activated by agonist to produce a physiological response

Most drugs are absorbed across cell membrane of the gut by the process

a. Diffusing through lipid

b. Pinocytosis

c. Diffusing through aqueous pores

d. Ion channel transport

e. Ion trapping

c. Diffusing through aqueous pores

Phase II drug metabolism

a. Includes hydrolytic reactions

b. Produces low molecular weight products

c. Usually forms inactive metabolites

d. Takes places mainly in kidneys

e. Requires NADPH as a cofactor

c. Usually forms inactive metabolites

Activation of adrenergic beta 2 receptors produces

a. Increases a chloride conductance

b. Decrease in chloride conductance

c. Relaxation of bronchial muscle (smooth)

d. Contraction of bronchial smooth muscle

e. Lacrimal gland secretion

c. Relaxation of bronchial muscle (smooth)

Activation of muscarinic m2 receptors

a. Increases calcium conductance

b. Increases potassium conductance

c. Increases cardiac rate and force

d. Causes central nervous system excitation

e. Produces vascular smooth muscle relaxation

b. Increases potassium conductance

Activation of muscarinic m3 receptors leads to

a. Smooth muscle relaxation

b. Cardiac slowing

c. Central nervous system stimulation

d. Bladder smooth muscle relaxation

e. Exocrine gland secretion

e. Exocrine gland secretion

The adverse effects of beta adrenoceptor antagonists include

a. Hyperglycemia

b. Cardiac arthymias

c. Mycardio ischemia

d. Anxiety

e. Broncho constriction

e. Broncho constriction

Nasal congestion can be improved by a

a. alpha 1 adrenoceptor antagonist

b. alpha 2 adrenoreceptors antagonist

c. alpha 1 adrenoceptor agonist

d. alpha 2 adrenoceptor agonist

e. non selective adrenoceptor agonist

c. alpha 1 adrenoceptor agonist

The opening of membrane potassium channels by minoxidel leads to

a. Increase potassium influx

b. Increase calcium influx

c. Inactivation of calcium channels

d. Membrane depolarization

e. Formation of cyclic GMP

c. Inactivation of calcium channels

Protein drug targets can include:

a. Receptors

b. Ion Channels

c. A and B

d. Carrier molecules

e. All of the these

e. All of the these

Vyvanse (lisdexamfetamine) is prescribed for treatment of ADHD. The coumpound is completely inactive until it encounters red blood cells which use enzymes to cleave the molecule into L-lysine and dexamfetamine. Vyvanse is an example of a(an):

a. Drug

b. Agonist

c. Antagonist

d. Pro-drug

e. Protein

d. Pro-drug

The binding equation is represented as B = Bmax*Xa/(Xa + Ka),

which term corresponds to the binding capacity?

a. Ka

b. Xa

c. Bmax

d. B

e. None of these

c. Bmax

What type of drugs freely diffuse across lipid membranes?

a. Non-polar

b. Polar

c. Ionic

d. Phasic

e. Diphasic

a. Non-polar

Which type of administration would normally result in the quickest

physiological response for a neurologically active drug:

a. Oral

b. Subcutaneuous

c. Intravenous

d. Intra-nasal

e. Inhalation

c. Intravenous

Benzodiazepines are a class of drugs associated with increased

activity of the GABAa receptor but does not bind in the GABA binding site,

therefore Benzodiazepines must be a(n):

a.Agonists

b. Antagonists

c. Competitive Antagonists

d. Modulator

e. None of these

d. Modulator

Rank these compounds in INCREASING level of toxicity: Nicotine

(LD50-1 mg/kg) Cyanide (LD50-10 mg/kg) Caffeine (LD50 ~200mg/kg),Ethanol (7 g/kg), Sarin (nerve agent) (LD50 - 0.5mg/kg) (DOUBLECHECK UNITS)

a. Sarin, Nicotine, Ethanol, Cyanide, Caffeine

b. Sarin, Nicotine, Cyanide, Caffeine, Ethanol

c. Ethanol, Caffeine, Cyanide, Nicotine, Sarin

d. Caffeine, Cyanide, Ethanol, Nicotine, Sarin

e. Cyanide, Sarin, Nicotine, Caffeine, Ethanol

c. Ethanol, Caffeine, Cyanide, Nicotine, Sarin

The tendency for a drug to BIND to a receptor is governed by it's

_________, the tendency for a drug to ACTIVATE a receptor by it's _______

a. Efficacy, affinity

b. Affinity, potency

c. Potency, efficacy

d. Affinity, efficacy

e. Potency, Affinity

d. Affinity, efficacy

A single nicotinic acetylcholine receptor subunit contains _____ transmembrane domains, and transmembrane domain _____ contains a kink the forms the channel gate.

a. 5, M1

b. 5, M2

c. 7, M4

d. 4, M1

e. 4, M2

e. 4, M2

The modern era of antimicrobial chemotherapy originated with the discovery of

a. penicillin

b. arsenical compounds

c. quinine

d. sulfonamides

e. calomel

b. arsenical compounds

Morphine was isolated from opium by

a. Paul Ehrlich

b. Gerhard Domagk

c. Friedrich Sertürner

d. Rudolf Buchheim

e. Henry Dale

c. Friedrich Sertürner

The use of genetic information to guide the choice of drug therapy is called

a. pharmacoepidemiology

b. pharmacogenetics

c. biotechnology

d. pharmacogenomics

e. pharmacoeconomics

d. pharmacogenomics

In the presence of a competitive antagonist, the agonist log-concentration effect curve is

a. shifted to the right without a change in slope or maximum effect

b. shifted to the left without a change in slope or maximum effect

c. shifted to the right with a decreased slope and maximum effect

d. shifted to the left with a decreased slope and maximum effect

e. not shifted right or left but shows a decreased maximum effect

a. shifted to the right without a change in slope or maximum effect

The magnitude of the response to a drug is related to the

a. total number of receptors for the drug

b. number of receptors occupied by the drug

c. number of vacant receptors in the tissue

d. number of spare receptors in the tissue

e. number of phosphorylated receptors in the tissue

b. number of receptors occupied by the drug

The Schild equation shows that the concentration ratio of an agonist required to occupy the same number of receptors in the absence and presence of a competitive antagonist is determined by the

a. equilibrium constant of the agonist

b. affinity of the agonist for its receptor

c. equilibrium constant of the antagonist

d. total number of available receptors

e. number of spare receptors in the tissue

c. equilibrium constant of the antagonist

A type of drug that reduces the slope and maximum response of an agonist is

a. a non-competitive antagonist

b. a competitive antagonist

c. a physiologic antagonist

d. an inverse agonist

e. a partial agonist

a. a non-competitive antagonist

Drugs that form covalent bonds with their receptors are usually

a. reversible competitive antagonists b. irreversible competitive antagonists

c. partial agonists

d. inverse agonists

e. inverse antagonists

b. irreversible competitive antagonists

A gradual decrease in the number of drug receptors is most likely to result from exposure to

a. a competitive antagonist

b. a non-competitive antagonist

c. an agonist

d. an inverse agonist

e. an antimetabolite

c. an agonist

The total number of receptor binding sites in a preparation and the binding equilibrium constant can be determined from a

a. total binding versus drug concentration curve

b. dose-response curve

c. Hill-Langmuir equation

d. Scatchard plot

e. Schild plot

d. Scatchard plot

Receptor desensitization typically results from

a. endocytosis of receptors

b. exposure to an inverse agonist

c. irreversible agonist binding

d. spare receptors

e. phosphorylation of receptor protein

e. phosphorylation of receptor protein

Which receptors are entirely located intracellularly?

a. G-protein-coupled receptors

b. nicotinic receptors

c. thyroid hormone receptors

d. cytokine and growth factor receptors

e. muscarinic receptors

c. thyroid hormone receptors

Which receptors are activated by proteolytic cleavage and inactivated by phosphorylation?

a. neurotransmitter receptors

b. cytokine receptors

c. growth factor receptors

d. thrombin receptors

e. insulin receptors

d. thrombin receptors

The treatment of chronic myeloid leukemia with imatinib results from the ability of the drug to inhibit a specific

a. ligand-gated ion channel

b. G-protein-coupled receptor

c. tyrosine kinase

d. Map (mitogen-activated protein) kinase

e. nuclear receptor

c. tyrosine kinase

Which type of receptors contains seven transmembrane helices?

a. nicotinic acetylcholine receptors

b. sodium channels

c. steroid hormone receptors

d. insulin receptors

e. G-protein-coupled receptors

e. G-protein-coupled receptors

The most rapid response is produced by activation of

a. kinase-linked receptors

b. G-protein coupled receptors

c. receptors activating gene transcription

d. ionotropic receptors

e. insulin receptors

d. ionotropic receptors

The opening of chloride ion channels by gamma-amino butyric acid is facilitated by

a. tricyclic antidepressant drugs

b. benzodiazepine drugs

c. local anesthetics

d. opioid analgesics

e. central nervous system stimulants

b. benzodiazepine drugs

Which ion inhibits an enzyme (inositol-1-phosphatase) in the phosphoinositol cycle?

a. calcium

b. ferrous

c. sodium

d. potassium

e. lithium

e. lithium

Receptors for insulin

a. contain tyrosine kinase in their intracellular domain

b. bind and activate intracellular kinases

c. exhibit phosphatase activity

d. phosphorylate DNA transcription factors

e. are linked to guanylate cyclase

a. contain tyrosine kinase in their intracellular domain

Myasthenia gravis is a disease in which

receptors have an abnormal amino acid sequence

G proteins have mutated

signal transmission pathways are defective

autoantibodies are directed against receptor proteins

nuclear receptors are down-regulated

Class I nuclear receptors that control gene transcription

a. contain cysteine residues bound to iron

b. interact with nucleolar RNA

c. bind to hormone response elements of DNA

d. only act to inhibit DNA transcription

e. only act to stimulate DNA transcription

c. bind to hormone response elements of DNA

Diacylglycerol produces its intracellular effects by

a. activating protein kinase C

b. activating protein kinase A

c. releasing intracellular calcium

d. activating adenylate cyclase

e. activating guanylate cyclase

a. activating protein kinase C

An agonist for a ligand-gated ion channel typically

a. increases channel conductance

b. increases the number of open channels

c. increases the rate of channel closing

d. alters channel ion selectivity

e. alters the open channel conformation

b. increases the number of open channels

In G-protein coupled receptor signal transduction, protein kinase A is typically activated by

a. inositol triphosphate

b. ATP

c. cyclic AMP

d. cyclic GMP

e. diacylglycerol

c. cyclic AMP

The nicotinic receptor is an example of a

a. G-protein coupled receptor

b. ligand-gated ion channel

c. tyrosine-kinase linked receptor

d. cytokine receptor

e. transport protein

b. ligand-gated ion channel

Coupling of a G-protein alpha subunit to an agonist-occupied receptor initially leads to

a. activation of the beta-gamma complex

b. hydrolysis of GTP

c. activation of adenylate cyclase

d. exchange of bound GDP with GTP

e. dissociation of the alpha-subunit from the receptor

d. exchange of bound GDP with GTP

Which signal transduction pathway is most important in cell division, growth, and differentiation?

a. beta-adrenoceptor signal pathways

b. phospholipase C pathways

c. Ras/Raf/Map kinase

d. eicosanoid signal pathways

e. guanylate cyclic signal pathways

c. Ras/Raf/Map kinase

Which second messenger in a G-protein coupled receptor signal transduction cascade typically increases intracellular calcium?

a. cyclic GMP

b. cyclic AMP

c. diacylglycerol

d. arachidonic acid

e. inositol triphosphate

e. inositol triphosphate

The Jak/Stat pathway of signal transduction responds to activation by

a. acetylcholine

b. steroid hormones

c. human growth hormone

d. cytokines

e. epinephrine

d. cytokines

In the growth factor kinase cascade, Map (mitogen-activated protein) kinase acts to phosphorylate

a. DNA

b. transcription factors

c. cyclic AMP

d. ion channels

e. transport proteins

b. transcription factors

Concerning the effect of pH on the urinary excretion of drugs, it can be correctly stated that

a. urinary acidification accelerates excretion of weak acids and bases

b. urinary alkalinization accelerates excretion of weak acids and bases

c. urinary acidification accelerates excretion of weak acids

d. urinary alkalinization accelerates excretion of weak acids

e. urinary alkalinization has no effect on excretion of weak bases

d. urinary alkalinization accelerates excretion of weak acids

Nitroglycerin and other organic nitrates produce their vasodilator effect by

a. increasing formation of cyclic AMP

b. increasing formation of cyclic GMP

c. blocking calcium channels

d. blocking adrenergic alpha receptors

e. activating potassium channels

b. increasing formation of cyclic GMP

Nitroglycerin relieves typical angina pectoris in part by

a. increasing cardiac stroke volume

b. dilating coronary arterioles

c. decreasing cardiac oxygen consumption

d. constricting collateral vessels in the heart

e. increasing blood pressure

c. decreasing cardiac oxygen consumption

Hypothyroidism is most likely to occur in persons who are taking

a. sotalol

b. flecainide

c. timolol

d. amiodarone

e. adenosine

amiodarone

Which drug has been shown to reduce mortality in persons who have had a myocardial infarction?

a. amiodarone

b. lidocaine

c. propranolol

d. amiodarone

e. verapamil

c. propranolol

The half-life of digoxin is considerably longer in persons with

a. renal insufficiency

b. pulmonary edema

c. atrial fibrillation

d. hypertension

e. endocarditis

a. renal insufficiency

Bioavailability is defined as the proportion of ingested drug that

a. is absorbed from the gastrointestinal tract

b. reaches the systemic circulation in an active form

c. crosses the blood-brain barrier

d. is unbound to plasma proteins

e. is distributed to the target tissue

b. reaches the systemic circulation in an active form

The rectal route of administration

a. provides nearly 100 percent bioavailability

b. is only used for localized effects

c. is suitable for persons with nausea and vomiting

d. is subject to a high degree of first-pass metabolism

e. is used for administration of nitroglycerin

c. is suitable for persons with nausea and vomiting

Digoxin slows AV conduction and decreases heart rate by

a. activating cardiac muscarinic receptors

b. blocking cardiac adrenergic beta-1 receptors

c. antagonizing cardiac calcium channels

d. increasing vagal outflow from the CNS

e. increasing cardiac contractile force

d. increasing vagal outflow from the CNS

Dobutamine is useful in treating acute heart failure because of its ability to

a. increase heart rate more than contractile force

b. increase contractile force more than heart rate

c. produce a negative dromotropic effect

d. cause cardiac stimulation and vasoconstriction

e. inhibit phosphodiesterase

b. increase contractile force more than heart rate

The passage of drugs across the blood-brain barrier

a. is facilitated by a high degree of drug ionization

b. is most rapid for drugs with low lipid solubility

c. occurs more readily in the chemoreceptor trigger zone

d. is reduced by inflammation of the meninges

e. is rapid with aminoglycoside antibiotics

c. occurs more readily in the chemoreceptor trigger zone

A calculated volume of distribution greater than total body water is most likely to occur with drugs that are

a. highly ionized

b. highly lipid soluble

c. subject to a high degree of first-pass inactivation

d. highly bound to plasma proteins

e. very large molecules

b. highly lipid soluble

In persons who have had a myocardial infarction, flecainide has been shown to

a. decrease the incidence of ventricular fibrillation

b. decrease the incidence of atrial fibrillation

c. decrease the incidence of sudden death

d. increase the frequency of ventricular ectopic beats

e. increase the incidence of sudden death

e. increase the incidence of sudden death

The pharmacokinetic attributes of amiodarone include

a. rapidly metabolized and excreted

b. a very short elimination half-life

c. a very long elimination half-life

d. distributed only to extracellular fluid

e. limited binding to plasma proteins

c. a very long elimination half-life

Drugs are most readily absorbed across cells of the

a. gastrointestinal tract

b. renal tubules

c. vascular endothelium

d. lung parenchyma

e. liver

c. vascular endothelium

The binding of drugs to plasma albumin

a. is usually irreversible

b. is saturable

c. is most important for basic drugs

d. accelerates drug metabolism

e. accelerates drug excretion

b. is saturable

Most drugs are absorbed across cell membranes of the gut by the process of

a. diffusing through lipid

b. pinocytosis

c. diffusing through aqueous pores

d. carrier-mediated transport

e. ion trapping

c. diffusing through lipid

Verapamil is indicated for the treatment of

a. supraventricular tachycardia

b. ventricular tachycardia

c. atrial fibrillation

d. ventricular fibrillation

e. cardiac asystole

a. supraventricular tachycardia

Drugs that increase serum digoxin levels include

a. furosemide

b. cholestyramine

c. amiodarone

d. enalapril

e. hydrochlorothiazide

c. amiodarone

Sotalol exerts an antiarrhythmic effect primarily by

a. slowing ventricular conduction

b. blocking sodium channels

c. slowing atrioventricular conduction

d. increasing the effective refractory period

e. decreasing action potential duration

d. increasing the effective refractory period

Which drug is absorbed by a membrane carrier that transports phenylalanine?

a. insulin

b. propranolol

c. levodopa

d. aspirin

e. penicillin

c. levodopa

In persons with atrial fibrillation, digoxin may slow the ventricular rate by

a. decreasing sinoatrial node automaticity

b. increasing ventricular contractility

c. inhibiting the Na+/K+ pump

d. reducing the calcium transient

e. slowing atrioventricular conduction

e. slowing atrioventricular conduction

Transdermal drug administration

a. is most suitable for highly polar drugs

b. is not subject to first-pass hepatic metabolism

c. provides rapid and complete absorption

d. is only used for localized effects

e. is most suitable for unconscious persons

b. is not subject to first-pass hepatic metabolism

The re-excitation of cardiac tissue prior to the next cardiac impulse occurs in the process known as

a. re-entry

b. ectopic automaticity

c. atrioventricular block

d. atrial fibrillation

e. bradycardia

a. re-entry

Delayed after-depolarizations in cardiac tissue typically result from an increased influx of

a. sodium

b. potassium

c. calcium

d. chloride

e. sodium and potassium

c. calcium

Persons with pheochromocytoma may benefit from administration of methyltyrosine because of its ability to

a. block alpha-1 adrenoceptors

b. block beta-1 adrenoceptors

c. inhibit norepinephrine release

d. inhibit norepinephrine synthesis

e. inhibit norepinephrine storage

d. inhibit norepinephrine synthesis

Symptoms of urinary retention due to benign prostatic hyperplasia may be improved by

a. alpha-1 adrenoceptor antagonists

b. alpha-2 adrenoceptor antagonists

c. alpha-1 adrenoceptor agonists

d. alpha-2 adrenoceptor agonists

e. nonselective adrenoceptor agonists

a. alpha-1 adrenoceptor antagonists

Persons with acute thyrotoxicosis are often treated with propranolol because it

a. reduces peripheral vascular resistance

b. increases cardiac output

c. decreases cardiac stimulation

d. decreases blood glucose levels

e. inhibits thyroid hormone secretion

c. decreases cardiac stimulation

Selective beta-3 adrenoceptor agonists are potentially useful in treating obesity because of their ability to

a. suppress appetite

b. inhibit digestion of fats

c. uncouple oxidative phosphorylation

d. increase thermogenesis

e. increase thyroid function

d. increase thermogenesis

The adverse effects of beta-adrenoceptor antagonists include

a. hyperglycemia

b. cardiac arrhythmias

c. myocardial ischemia

d. anxiety

e. bronchoconstriction

e. bronchoconstriction

Hepatic cytochrome P450 drug-metabolizing enzymes are primarily found in

a. cell nuclei

b. plasma membranes

c. the cytoplasm

d. the smooth endoplasmic reticulum

e. mitochondria

d. the smooth endoplasmic reticulum

In the peripheral tissues, the primary end product of norepinephrine metabolism is

a. 3-methoxy, 4-hydroxyphenylglycol

b. normetanephrine

c. vanillylmandelic acid

d. 3,4-dihydroxymandelic acid

e. 3,4-dihydroxyphenylglycol

c. vanillylmandelic acid

Phase II drug metabolism

a. includes hydrolytic reactions

b. produces low molecular weight products

c. usually forms inactive metabolites

d. takes place mainly in the kidneys

e. requires NADPH as a cofactor

c. usually forms inactive metabolites

Ketoconazole produces non-competitive inhibition of cytochrome P450 by

a. binding to the ferric form of heme iron

b. binding to the active site of the enzyme

c. causing enzyme autolysis

d. oxidizing NADPH

e. binding covalently to the P450 protein

a. binding to the ferric form of heme iron

Which adrenergic receptor antagonist increases heart rate at rest but reduces it during exercise?

a. pindolol

b. propranolol

c. prazosin

d. timolol

e. phentolamine

a. pindolol

The first-line treatment for acute severe type I hypersensitivity reactions is

a. dopamine

b. epinephrine

c. isoproterenol

d. norepinephrine

e. phenylephrine

b. epinephrine