Pharm 44 Flashcards

Which ribosomal subunit is targeted by tetracyclines?

A) 50S subunit

B) 30S subunit

C) 40S subunit

D) 60S subunit

What is the primary mechanism of action of tetracyclines?

A) Inhibition of DNA replication

B) Inhibition of cell wall synthesis

C) Inhibition of folate metabolism

D) Inhibition of bacterial protein synthesis

Tetracyclines generally produce which type of antibacterial activity?

A) Bacteriostatic

B) Bactericidal

C) Bacteriolytic

D) Fungicidal

Which group of infections is commonly treated with tetracyclines?

A) Enterococcal and pseudomonal infections

B) Candidal and aspergillus infections

C) Mycoplasma, chlamydial, and rickettsial infections

D) Influenza and herpesvirus infections

Which combination includes additional clinical uses of tetracyclines?

A) Candidiasis, influenza, tuberculosis

B) Acne, malaria prophylaxis, H. pylori

C) Herpes encephalitis, HIV, hepatitis

D) Pneumocystis, aspergillosis, cryptococcosis

Which adverse effects are characteristic of tetracyclines?

A) Ototoxicity and nephrotoxicity

B) Peripheral neuropathy and thrombocytopenia

C) Tendon rupture and seizures

D) Photosensitivity and tooth discoloration

Tetracyclines can accumulate in developing bones and teeth through binding to which mineral?

A) Calcium

B) Potassium

C) Sodium

D) Chloride

Which additional toxicities are associated with tetracyclines?

A) Optic neuritis and colitis

B) Gray baby syndrome and anemia

C) Gastrointestinal upset and hepatotoxicity

D) Myalgias and arthralgias

Which ribosomal subunit is targeted by erythromycin?

A) 30S subunit

B) 50S subunit

C) 40S subunit

D) 60S subunit

Erythromycin belongs to which antibiotic class?

A) Macrolides

B) Lincosamides

C) Streptogramins

D) Oxazolidinones

Erythromycin generally produces which antibacterial effect?

A) Bacteriolytic

B) Fungistatic

C) Bacteriostatic

D) Fungicidal

Which infections can be treated with erythromycin when organisms are susceptible?

A) Pseudomonal sepsis and meningitis

B) MRSA bacteremia and candidiasis

C) Tuberculosis and invasive aspergillosis

D) Pertussis and atypical pneumonia

Which cardiac adverse effect is associated with erythromycin?

A) QT interval prolongation

B) Sinus node destruction

C) Complete atrioventricular blockade

D) Myocardial fibrosis

Which additional toxicities are associated with erythromycin?

A) Aplastic anemia and neuropathy

B) Gastrointestinal upset and hepatotoxicity

C) Tooth discoloration and photosensitivity

D) Severe myalgias and arthralgias

Clindamycin belongs to which antibiotic class?

A) Macrolides

B) Streptogramins

C) Oxazolidinones

D) Lincosamides

Which ribosomal subunit is targeted by clindamycin?

A) 30S subunit

B) 40S subunit

C) 50S subunit

D) 60S subunit

Clindamycin is primarily used for which infections?

A) Anaerobic and skin infections

B) Influenza and herpes infections

C) Malaria and rickettsial infections

D) Pseudomonal and fungal infections

Which serious gastrointestinal complication is strongly associated with clindamycin?

A) Acute pancreatitis

B) Clostridioides difficile colitis

C) Ischemic colitis

D) Ulcerative colitis

Which antibiotic combination belongs to the streptogramin class?

A) Trimethoprim-sulfamethoxazole

B) Amoxicillin-clavulanate

C) Piperacillin-tazobactam

D) Quinupristin-dalfopristin

Which ribosomal subunit is targeted by quinupristin-dalfopristin?

A) 30S subunit

B) 40S subunit

C) 50S subunit

D) 60S subunit

Quinupristin-dalfopristin produces which activity against susceptible staphylococci?

A) Synergistic bactericidal activity

B) Exclusively bacteriostatic activity

C) Primarily antiviral activity

D) Exclusively antifungal activity

Which vancomycin-resistant organism can be treated with quinupristin-dalfopristin?

A) Enterococcus faecalis

B) Enterococcus faecium

C) Pseudomonas aeruginosa

D) Escherichia coli

Which adverse effects are especially associated with quinupristin-dalfopristin?

A) Tooth discoloration and photosensitivity

B) Gray baby syndrome

C) Optic neuritis and neuropathy

D) Severe myalgias and arthralgias

Which ribosomal subunit is targeted by chloramphenicol?

A) 30S subunit

B) 40S subunit

C) 50S subunit

D) 60S subunit

Chloramphenicol generally produces which antibacterial effect?

A) Bacteriostatic

B) Bacteriolytic

C) Fungicidal

D) Virucidal

Which serious hematologic toxicities limit chloramphenicol use?

A) Thrombocytosis and polycythemia

B) Neutrophilia and erythrocytosis

C) Leukocytosis and lymphocytosis

D) Dose-related anemia and aplastic anemia

Which neonatal toxicity is classically associated with chloramphenicol?

A) Kernicterus

B) Gray baby syndrome

C) Reye syndrome

D) Hemolytic uremic syndrome

Which antibiotic binds 23S rRNA of the 50S ribosomal subunit and inhibits initiation of protein synthesis?

A) Erythromycin

B) Tetracycline

C) Linezolid

D) Clindamycin

Linezolid belongs to which antibiotic class?

A) Oxazolidinones

B) Macrolides

C) Streptogramins

D) Pleuromutilins

Which resistant bacterial infections can be treated with linezolid?

A) Pseudomonas and Acinetobacter

B) Salmonella and Shigella

C) Chlamydia and Rickettsia

D) MRSA and VRE

Which hematologic adverse effect is associated with prolonged linezolid therapy?

A) Polycythemia

B) Myelosuppression

C) Thrombocytosis

D) Eosinophilia

Prolonged linezolid treatment can cause which neurological toxicities?

A) Seizures and meningitis

B) Ataxia and hydrocephalus

C) Peripheral and optic neuropathy

D) Parkinsonism and chorea

A patient taking an SSRI develops agitation, hyperthermia, and hyperreflexia after starting linezolid. Which complication is most likely?

A) Serotonin syndrome

B) Neuroleptic malignant syndrome

C) Malignant hyperthermia

D) Anticholinergic toxicity

Lefamulin belongs to which antibiotic class?

A) Lincosamides

B) Oxazolidinones

C) Streptogramins

D) Pleuromutilins

Which ribosomal subunit is targeted by lefamulin?

A) 30S subunit

B) 50S subunit

C) 40S subunit

D) 60S subunit

What is a primary clinical indication for lefamulin?

A) Pseudomonal bacteremia

B) Invasive candidiasis

C) Community-acquired bacterial pneumonia

D) Tuberculous meningitis

Lefamulin produces which antibacterial effect against susceptible Streptococcus pneumoniae?

A) Bactericidal

B) Fungicidal

C) Virucidal

D) Bacteriostatic

Which adverse effects are commonly associated with lefamulin?

A) Aplastic anemia and neuropathy

B) Tooth discoloration and hepatotoxicity

C) Severe arthralgias and myalgias

D) Gastrointestinal and infusion-site reactions

What does tetracycline prevent from binding to the bacterial ribosome?

A) Peptidyltransferase

B) Messenger RNA

C) Aminoacyl-tRNA

D) Release factors

Which ribosomal site is blocked by tetracyclines?

A) A site

B) P site

C) E site

D) Exit tunnel

How do tetracyclines bind to the bacterial ribosome?

A) Irreversibly

B) Covalently

C) Permanently

D) Reversibly

Which substances decrease gastrointestinal absorption of tetracyclines?

A) Monosaccharides

B) Multivalent cations

C) Amino acids

D) Fatty acids

Which combination can impair tetracycline absorption?

A) Glucose, fructose, sucrose

B) Sodium, potassium, chloride

C) Calcium, magnesium, iron

D) Bicarbonate, phosphate, water

Which antibiotic is first-line treatment for most rickettsial infections?

A) Doxycycline

B) Erythromycin

C) Clindamycin

D) Linezolid

Which antibiotic is commonly used to treat early Lyme disease caused by Borrelia burgdorferi?

A) Vancomycin

B) Gentamicin

C) Clindamycin

D) Doxycycline

Which tetracycline derivative has historically been used to treat SIADH?

A) Tigecycline

B) Demeclocycline

C) Minocycline

D) Doxycycline

How does demeclocycline help correct hyponatremia in SIADH?

A) Increases aldosterone secretion

B) Stimulates ADH release

C) Reduces renal ADH responsiveness

D) Increases sodium cotransport

Which tetracycline-related antibiotic has activity against MRSA and VRE?

A) Tigecycline

B) Demeclocycline

C) Tetracycline

D) Sarecycline

Why are tetracyclines generally avoided during pregnancy?

A) Cause maternal hypoglycemia

B) Prevent fetal lung development

C) Produce fetal thrombocytopenia

D) Affect fetal bones and teeth

What step of protein synthesis is inhibited by macrolides?

A) Aminoacyl-tRNA charging

B) Ribosomal translocation

C) DNA strand elongation

D) Folate synthesis

Which molecular change commonly causes bacterial resistance to macrolides?

A) Decreased peptidoglycan cross-linking

B) Increased folate synthesis

C) Methylation of 23S rRNA

D) Destruction of bacterial DNA

Which enzyme system is significantly inhibited by erythromycin?

A) Cytochrome P450

B) Adenylyl cyclase

C) DNA gyrase

D) Acetylcholinesterase

Erythromycin can increase concentrations of which medication through metabolic inhibition?

A) Amoxicillin

B) Acetaminophen

C) Metformin

D) Theophylline

Which receptor does erythromycin stimulate to increase gastrointestinal motility?

A) Gastrin receptor

B) Motilin receptor

C) Secretin receptor

D) Histamine H2 receptor

Which macrolide generally causes greater gastrointestinal intolerance?

A) Azithromycin

B) Clarithromycin

C) Erythromycin

D) Roxithromycin

Macrolide-induced QT prolongation increases the risk of which arrhythmia?

A) Torsades de pointes

B) Sinus bradycardia

C) First-degree AV block

D) Junctional escape rhythm

Clindamycin is particularly useful against susceptible anaerobic bacteria originating from which region?

A) Urinary tract

B) Central nervous system

C) Lower intestinal tract

D) Oral cavity

Which enzyme is directly inhibited by chloramphenicol?

A) DNA polymerase

B) Peptidyltransferase

C) RNA polymerase

D) Dihydrofolate reductase

Chloramphenicol has activity against which bacterial groups?

A) Only aerobic Gram-positive bacteria

B) Only anaerobic Gram-negative bacteria

C) Aerobic and anaerobic bacteria

D) Only intracellular bacteria

What propety does chloramphenicol have?

A) Blood-brain barrier penetration

B) Exclusive renal elimination

C) Strong plasma protein binding

D) Poor tissue distribution

What distinguishes chloramphenicol-associated aplastic anemia from its reversible marrow suppression?

A) Always occurs during infancy

B) Requires prolonged high doses

C) Results from folate depletion

D) Idiosyncratic and dose-independent

Which enzyme deficiency contributes to gray baby syndrome in neonates receiving chloramphenicol?

A) Glucose-6-phosphate dehydrogenase

B) UDP-glucuronosyltransferase

C) Dihydrofolate reductase

D) Pyruvate kinase

Which step of bacterial protein synthesis is specifically blocked by linezolid?

A) Peptide bond hydrolysis

B) Aminoacyl-tRNA synthesis

C) Initiation complex formation

D) Ribosomal subunit degradation

Linezolid is primarily effective against which bacterial category?

A) Gram-positive bacteria

B) Gram-negative bacteria

C) Acid-fast bacteria exclusively

D) Anaerobic protozoa