USMLE STEP 1 PHARMACOLOGY EXAM 2024/2025 WITH 100%
ACCURATE SOLUTIONS
What effect does nitrates + β-blockers have on EDV?-AnswerNo effect
or decrease
Short acting insulin clinical use-AnswerType 1 DM, type 2 DM, GDM,
DKA (IV), hyperkalemia (+ glucose), stress hyperglycemia.
Cocaine withdrawal-AnswerHypersomnolence, malaise, severe
psychological craving, depression/suicidality.
What are the major functions of the α2 receptor?-AnswerDecrease
sympathetic outflow, decrease insulin release, decrease lipolysis,
increase platelet aggregation, decrease aqueous humor production
Ciguatoxin-Answer-Consumption of reef fish (e.g. barracuda, snapper,
eel...)
-Causes ciguatera fish poisoning.
-Opens Na+ channels causing depolarization. Symptoms easily confused
with cholinergic poisoning.
-Temperature-related dysesthesia (e.g., "cold feels hot; hot feels cold") is
regarded as a specific finding of ciguatera.
-Treatment is primarily supportive.
,Drugs that cause agranulocytosis-AnswerGanciclovir, Clozapine,
Carbamazepine, Colchicine, Methimazole, Propylthiouracil
Sulfa drugs-AnswerProbenecid, Furosemide, Acetazolamide, Celecoxib,
Thiazides, Sulfonamide antibiotics, Sulfasalazine, Sulfonylureas.
Patients with sulfa allergies may develop
fever, urinary tract infection, Stevens-
Johnson syndrome, hemolytic anemia, thrombocytopenia,
agranulocytosis, and urticaria (hives). Symptoms range from mild to life
threatening.
-ipramine, -triptyline-AnswerTCA
Amoxicillin, ampicillin (aminopenicillins)-Answer-Penicillinase-
sensitive penicillins
-Same mechanism as penicillin (inhibits peptidoglycan cross-linking)
with wider spectrum;
-Penicillinase sensitive (ombine with clavulanic acid to protect against
destruction by β-lactamase)
-Use: extended-spectrum penicillin—H. influenzae, H. pylori, E. coli,
Listeria monocytogenes, Proteus mirabilis, Salmonella, Shigella,
enterococci.
-Toxicity: Hypersensitivity reactions; rash; pseudomembranous colitis.
-Resistance: penicillinase in bacteria (a type of β-lactamase) cleaves β-
lactam ring.
,Linezolid-Answer-Oxazolidinone
-Inhibit protein synthesis by binding to 50S subunit and preventing
formation of the initiation complex.
-Gram-positive species including MRSA and VRE.
-Toxicity: Bone marrow suppression (especially thrombocytopenia),
peripheral neuropathy, serotonin syndrome.
-Resistance: Point mutation of ribosomal RNA.
What is the prophylaxis for M. avium-intracellulare?-
AnswerAzithromycin, rifabutin
Amphotericin B MoA-Answer-Binds ergosterol (unique to fungi); forms
membrane pores that allow leakage of electrolytes.
-Amphotericin "tears" holes in the fungal membrane by forming pores
Azoles clinical use-AnswerLocal and less serious systemic mycoses.
Fluconazole for chronic suppression of cryptococcal meningitis in AIDS
patients and candidal infections of all types. Itraconazole for
Blastomyces, Coccidioides, Histoplasma. Clotrimazole and miconazole
for topical fungal infections.
NRTI mechanism of action-Answer-Competitively inhibit nucleotide
binding to reverse transcriptase and terminate the DNA chain (lack a 3′
OH group). Tenofovir is a nucleoTide; the others are nucleosides and
need to be phosphorylated to be active.
, -ZDV is used for general prophylaxis and during pregnancy to risk of
fetal transmission.
Adverse effect of fluorquinolones during pregnancy-AnswerCartilage
damage
Adverse effect of griseofulvin during pregnancy-AnswerTeratogenic
Cyclosporine MoA-AnswerCalcineurin inhibitor; binds cyclophilin.
Blocks T-cell activation by preventing IL-2 transcription.
Cyclosporine clinical use-AnswerTransplant rejection prophylaxis,
psoriasis, rheumatoid arthritis
Tacrolimus MoA-Answer-Calcineurin inhibitor; binds FK506 binding
protein (FKBP).
-Blocks T-cell activation by preventing IL-2 transcription.
Calcium channel blockers mechanism-Answer-Block voltage-dependent
L-type calcium channels of cardiac and smooth muscle to decrease
muscle contractility.
-Vascular smooth muscle—amlodipine = nifedipine > diltiazem >
verapamil.
-Heart—verapamil > diltiazem > amlodipine = nifedipine (verapamil =
ventricle).
ACCURATE SOLUTIONS
What effect does nitrates + β-blockers have on EDV?-AnswerNo effect
or decrease
Short acting insulin clinical use-AnswerType 1 DM, type 2 DM, GDM,
DKA (IV), hyperkalemia (+ glucose), stress hyperglycemia.
Cocaine withdrawal-AnswerHypersomnolence, malaise, severe
psychological craving, depression/suicidality.
What are the major functions of the α2 receptor?-AnswerDecrease
sympathetic outflow, decrease insulin release, decrease lipolysis,
increase platelet aggregation, decrease aqueous humor production
Ciguatoxin-Answer-Consumption of reef fish (e.g. barracuda, snapper,
eel...)
-Causes ciguatera fish poisoning.
-Opens Na+ channels causing depolarization. Symptoms easily confused
with cholinergic poisoning.
-Temperature-related dysesthesia (e.g., "cold feels hot; hot feels cold") is
regarded as a specific finding of ciguatera.
-Treatment is primarily supportive.
,Drugs that cause agranulocytosis-AnswerGanciclovir, Clozapine,
Carbamazepine, Colchicine, Methimazole, Propylthiouracil
Sulfa drugs-AnswerProbenecid, Furosemide, Acetazolamide, Celecoxib,
Thiazides, Sulfonamide antibiotics, Sulfasalazine, Sulfonylureas.
Patients with sulfa allergies may develop
fever, urinary tract infection, Stevens-
Johnson syndrome, hemolytic anemia, thrombocytopenia,
agranulocytosis, and urticaria (hives). Symptoms range from mild to life
threatening.
-ipramine, -triptyline-AnswerTCA
Amoxicillin, ampicillin (aminopenicillins)-Answer-Penicillinase-
sensitive penicillins
-Same mechanism as penicillin (inhibits peptidoglycan cross-linking)
with wider spectrum;
-Penicillinase sensitive (ombine with clavulanic acid to protect against
destruction by β-lactamase)
-Use: extended-spectrum penicillin—H. influenzae, H. pylori, E. coli,
Listeria monocytogenes, Proteus mirabilis, Salmonella, Shigella,
enterococci.
-Toxicity: Hypersensitivity reactions; rash; pseudomembranous colitis.
-Resistance: penicillinase in bacteria (a type of β-lactamase) cleaves β-
lactam ring.
,Linezolid-Answer-Oxazolidinone
-Inhibit protein synthesis by binding to 50S subunit and preventing
formation of the initiation complex.
-Gram-positive species including MRSA and VRE.
-Toxicity: Bone marrow suppression (especially thrombocytopenia),
peripheral neuropathy, serotonin syndrome.
-Resistance: Point mutation of ribosomal RNA.
What is the prophylaxis for M. avium-intracellulare?-
AnswerAzithromycin, rifabutin
Amphotericin B MoA-Answer-Binds ergosterol (unique to fungi); forms
membrane pores that allow leakage of electrolytes.
-Amphotericin "tears" holes in the fungal membrane by forming pores
Azoles clinical use-AnswerLocal and less serious systemic mycoses.
Fluconazole for chronic suppression of cryptococcal meningitis in AIDS
patients and candidal infections of all types. Itraconazole for
Blastomyces, Coccidioides, Histoplasma. Clotrimazole and miconazole
for topical fungal infections.
NRTI mechanism of action-Answer-Competitively inhibit nucleotide
binding to reverse transcriptase and terminate the DNA chain (lack a 3′
OH group). Tenofovir is a nucleoTide; the others are nucleosides and
need to be phosphorylated to be active.
, -ZDV is used for general prophylaxis and during pregnancy to risk of
fetal transmission.
Adverse effect of fluorquinolones during pregnancy-AnswerCartilage
damage
Adverse effect of griseofulvin during pregnancy-AnswerTeratogenic
Cyclosporine MoA-AnswerCalcineurin inhibitor; binds cyclophilin.
Blocks T-cell activation by preventing IL-2 transcription.
Cyclosporine clinical use-AnswerTransplant rejection prophylaxis,
psoriasis, rheumatoid arthritis
Tacrolimus MoA-Answer-Calcineurin inhibitor; binds FK506 binding
protein (FKBP).
-Blocks T-cell activation by preventing IL-2 transcription.
Calcium channel blockers mechanism-Answer-Block voltage-dependent
L-type calcium channels of cardiac and smooth muscle to decrease
muscle contractility.
-Vascular smooth muscle—amlodipine = nifedipine > diltiazem >
verapamil.
-Heart—verapamil > diltiazem > amlodipine = nifedipine (verapamil =
ventricle).
