Anti-infective Drugs Practice Exam

Anti-infective Drugs Practice Exam

What is the mechanism of action of beta-lactam antibiotics?

Answer: Beta-lactam antibiotics work by inhibiting bacterial cell wall synthesis. They bind to penicillin-binding proteins (PBPs) and prevent the final step of cell wall assembly, causing cell lysis.

Explanation: Without a proper cell wall, bacteria cannot maintain their structural integrity and will burst due to osmotic pressure.

Which of the following antibiotics is classified as a macrolide?

A) Amoxicillin
B) Azithromycin
C) Ciprofloxacin
D) Doxycycline

Answer: B) Azithromycin

Explanation: Azithromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit.

What is the primary use of fluoroquinolones?

Answer: Fluoroquinolones are primarily used to treat infections caused by gram-negative bacteria, such as urinary tract infections and respiratory tract infections.

Explanation: Fluoroquinolones inhibit bacterial DNA gyrase and topoisomerase IV, enzymes essential for DNA replication.

Which of the following drugs is used to treat fungal infections?

A) Isoniazid
B) Fluconazole
C) Rifampin
D) Metronidazole

Answer: B) Fluconazole

Explanation: Fluconazole is an antifungal medication that inhibits the synthesis of ergosterol, an essential component of fungal cell membranes.

What is the mechanism of action of tetracyclines?

Answer: Tetracyclines inhibit bacterial protein synthesis by binding to the 30S ribosomal subunit, preventing tRNA from binding to the ribosome.

Explanation: This prevents the elongation of the polypeptide chain, halting protein synthesis in bacteria.

Which of the following is a common side effect of aminoglycosides?

A) Ototoxicity
B) Hyperkalemia
C) Hypoglycemia
D) Hypertension

Answer: A) Ototoxicity

Explanation: Aminoglycosides can cause damage to the inner ear, leading to hearing loss or balance issues.

What is the first-line treatment for tuberculosis?

Answer: The first-line treatment for tuberculosis includes a combination of isoniazid, rifampin, pyrazinamide, and ethambutol.

Explanation: This regimen targets different stages of Mycobacterium tuberculosis’s life cycle, preventing the development of resistance.

What class of drugs does ciprofloxacin belong to?

Answer: Ciprofloxacin is a fluoroquinolone.

Explanation: Ciprofloxacin inhibits bacterial DNA gyrase and topoisomerase IV, making it effective against a wide range of bacteria.

Which of the following is an antiviral medication used to treat influenza?

A) Acyclovir
B) Oseltamivir
C) Clindamycin
D) Rifampin

Answer: B) Oseltamivir

Explanation: Oseltamivir inhibits neuraminidase, an enzyme needed for the release of new viral particles from infected cells, helping reduce the duration of influenza symptoms.

What is the mechanism of action of sulfonamides?

Answer: Sulfonamides inhibit the synthesis of folic acid in bacteria by acting as a competitive inhibitor of dihydropteroate synthase.

Explanation: Folic acid is essential for bacterial DNA synthesis, and without it, bacteria cannot proliferate.

Which antibiotic is commonly used to treat methicillin-resistant Staphylococcus aureus (MRSA)?

A) Cephalexin
B) Vancomycin
C) Penicillin
D) Amoxicillin

Answer: B) Vancomycin

Explanation: Vancomycin inhibits bacterial cell wall synthesis and is effective against MRSA, a strain resistant to many other antibiotics.

What is the common side effect of nitrofurantoin in patients with impaired renal function?

Answer: Nitrofurantoin can cause pulmonary toxicity, including pneumonitis and fibrosis.

Explanation: Patients with impaired renal function cannot clear the drug effectively, leading to accumulation and toxicity.

Which of the following drugs is used to treat malaria?

A) Metronidazole
B) Quinine
C) Azithromycin
D) Rifampin

Answer: B) Quinine

Explanation: Quinine is an antimalarial drug that interferes with the parasite’s ability to metabolize hemoglobin in red blood cells.

Which of the following is a common side effect of antibiotics in the penicillin class?

A) Hepatotoxicity
B) Allergic reactions
C) Cardiotoxicity
D) Hematuria

Answer: B) Allergic reactions

Explanation: Penicillin can cause allergic reactions, ranging from mild rashes to severe anaphylaxis.

Which antibiotic is effective against Pseudomonas aeruginosa?

A) Amoxicillin
B) Piperacillin
C) Erythromycin
D) Doxycycline

Answer: B) Piperacillin

Explanation: Piperacillin is a broad-spectrum penicillin with enhanced activity against Pseudomonas aeruginosa.

What is the mechanism of action of metronidazole?

Answer: Metronidazole is a prodrug that, once inside the bacterial or parasitic cell, is reduced to its active form, which causes DNA strand breakage and inhibits nucleic acid synthesis.

Explanation: This mechanism is particularly effective against anaerobic bacteria and protozoa.

What type of infections are treated with doxycycline?

Answer: Doxycycline is used to treat a variety of infections, including respiratory infections, urinary tract infections, and tick-borne diseases like Lyme disease.

Explanation: Doxycycline is a tetracycline that inhibits protein synthesis in bacteria.

Which of the following is a common side effect of fluconazole?

A) Diarrhea
B) Hepatotoxicity
C) Photosensitivity
D) Tinnitus

Answer: B) Hepatotoxicity

Explanation: Fluconazole can cause liver damage, particularly in patients with preexisting liver conditions.

Which of the following drugs is used to treat a herpes simplex virus infection?

A) Oseltamivir
B) Acyclovir
C) Azithromycin
D) Rifampin

Answer: B) Acyclovir

Explanation: Acyclovir is an antiviral that inhibits the replication of herpes simplex virus by inhibiting viral DNA polymerase.

Which of the following antibiotics can be used to treat Clostridium difficile infection?

A) Metronidazole
B) Amoxicillin
C) Vancomycin
D) Penicillin

Answer: A) Metronidazole

Explanation: Metronidazole is effective against anaerobic bacteria, including Clostridium difficile, and is often used as first-line treatment for mild cases of infection.

What class of drug is used to treat infections caused by Mycobacterium tuberculosis?

A) Macrolides
B) Antifungals
C) Antituberculars
D) Fluoroquinolones

Answer: C) Antituberculars

Explanation: Antitubercular drugs like isoniazid, rifampin, and pyrazinamide are specifically used to treat tuberculosis.

What is a common adverse effect of rifampin?

A) Hepatotoxicity
B) Hypoglycemia
C) Discoloration of urine
D) Hypertension

Answer: C) Discoloration of urine

Explanation: Rifampin causes orange or red discoloration of bodily fluids, including urine, tears, and sweat.

Which of the following is used to treat infections caused by Trichomonas vaginalis?

A) Miconazole
B) Metronidazole
C) Fluconazole
D) Clindamycin

Answer: B) Metronidazole

Explanation: Metronidazole is effective against protozoal infections like Trichomonas vaginalis.

What is the primary mechanism of action of quinolones?

Answer: Quinolones inhibit bacterial DNA gyrase and topoisomerase IV, enzymes that are necessary for bacterial DNA replication.

Explanation: By inhibiting these enzymes, quinolones prevent bacterial cells from replicating and repairing their DNA, leading to cell death.

Which antibiotic is effective against anaerobic bacteria?

A) Penicillin
B) Clindamycin
C) Ciprofloxacin
D) Azithromycin

Answer: B) Clindamycin

Explanation: Clindamycin is a lincosamide antibiotic that is effective against anaerobic bacteria by inhibiting bacterial protein synthesis.

Which of the following is used to treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA)?

A) Penicillin
B) Vancomycin
C) Cephalexin
D) Amoxicillin

Answer: B) Vancomycin

Explanation: Vancomycin is effective against MRSA, a strain resistant to many other antibiotics, including penicillin and cephalosporins.

Which antibiotic is known to cause photosensitivity?

A) Tetracycline
B) Penicillin
C) Erythromycin
D) Gentamicin

Answer: A) Tetracycline

Explanation: Tetracyclines, such as doxycycline, can increase sensitivity to sunlight, causing sunburns or skin rashes upon exposure to the sun.

What is the primary use of albendazole?

Answer: Albendazole is used to treat parasitic infections such as tapeworms, roundworms, and hookworms.

Explanation: Albendazole inhibits the microtubule formation in parasitic cells, disrupting their metabolism and leading to cell death.

Which class of antibiotics does azithromycin belong to?

Answer: Azithromycin is a macrolide antibiotic.

Explanation: Azithromycin works by binding to the 50S ribosomal subunit, inhibiting bacterial protein synthesis.

Which of the following drugs is used to treat infections caused by Candida species?

A) Fluconazole
B) Ciprofloxacin
C) Rifampin
D) Metronidazole

Answer: A) Fluconazole

Explanation: Fluconazole is an antifungal medication used to treat infections caused by Candida species, such as oral thrush and vaginal yeast infections.

Which of the following is an adverse effect of sulfonamide antibiotics?

A) Stevens-Johnson syndrome
B) Photosensitivity
C) C. difficile infection
D) Nephrotoxicity

Answer: A) Stevens-Johnson syndrome

Explanation: Sulfonamides can cause severe skin reactions, including Stevens-Johnson syndrome, which is a life-threatening condition.

Which antibiotic should be avoided during pregnancy due to its teratogenic effects?

A) Penicillin
B) Tetracycline
C) Amoxicillin
D) Erythromycin

Answer: B) Tetracycline

Explanation: Tetracyclines can cause discoloration of the teeth and inhibit bone growth in the developing fetus.

Which drug is used to treat urinary tract infections caused by E. coli?

A) Ciprofloxacin
B) Amoxicillin
C) Clindamycin
D) Rifampin

Answer: A) Ciprofloxacin

Explanation: Ciprofloxacin is a fluoroquinolone that is effective against E. coli, a common cause of urinary tract infections.

Which of the following drugs is used to treat Herpes Simplex Virus (HSV)?

A) Ribavirin
B) Acyclovir
C) Amoxicillin
D) Ceftriaxone

Answer: B) Acyclovir

Explanation: Acyclovir is an antiviral drug used to treat infections caused by Herpes Simplex Virus, including cold sores and genital herpes.

What is the mechanism of action of sulfonamides?

Answer: Sulfonamides inhibit the bacterial enzyme dihydropteroate synthase, which is essential for the synthesis of folic acid.

Explanation: By inhibiting folic acid synthesis, sulfonamides prevent bacteria from synthesizing DNA and RNA, leading to their inability to proliferate.

What is a potential side effect of using antibiotics like amoxicillin or penicillin?

A) Diarrhea
B) Hepatotoxicity
C) Seizures
D) Hallucinations

Answer: A) Diarrhea

Explanation: Antibiotics like amoxicillin or penicillin can disrupt the normal gut flora, leading to diarrhea and gastrointestinal disturbances.

What is the action of the drug oseltamivir in the treatment of influenza?

Answer: Oseltamivir inhibits neuraminidase, an enzyme that the flu virus needs to release new viral particles from infected cells.

Explanation: By blocking neuraminidase, oseltamivir reduces the spread of the virus within the body.

Which of the following is used to treat a Giardia intestinal infection?

A) Rifampin
B) Metronidazole
C) Miconazole
D) Clindamycin

Answer: B) Metronidazole

Explanation: Metronidazole is used to treat Giardia intestinalis, a protozoan parasite that causes gastrointestinal symptoms.

Which of the following drugs is a nucleoside analog used to treat HIV infection?

A) Zidovudine
B) Rifampin
C) Isoniazid
D) Cefazolin

Answer: A) Zidovudine

Explanation: Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) used to treat HIV infection by inhibiting the reverse transcriptase enzyme, essential for viral replication.

What is the most common adverse effect of the antibiotic clindamycin?

A) C. difficile-associated diarrhea
B) Photosensitivity
C) Ototoxicity
D) Hypotension

Answer: A) C. difficile-associated diarrhea

Explanation: Clindamycin disrupts the normal flora of the intestines, increasing the risk of C. difficile overgrowth and causing severe diarrhea.

Which of the following antifungal agents is used topically for fungal infections of the skin?

A) Ketoconazole
B) Griseofulvin
C) Amphotericin B
D) Terbinafine

Answer: D) Terbinafine

Explanation: Terbinafine is commonly used topically for fungal infections of the skin and nails, such as athlete’s foot.

What is the primary action of zidovudine in the treatment of HIV?

Answer: Zidovudine is a reverse transcriptase inhibitor that blocks the conversion of viral RNA to DNA.

Explanation: By inhibiting reverse transcriptase, zidovudine prevents HIV from replicating and integrating into host cells.

Which of the following is an example of a broad-spectrum antibiotic?

A) Penicillin
B) Ciprofloxacin
C) Cephalexin
D) Erythromycin

Answer: B) Ciprofloxacin

Explanation: Ciprofloxacin is a fluoroquinolone with a broad spectrum of activity against both gram-positive and gram-negative bacteria.

Which of the following medications can cause “red man syndrome”?

A) Rifampin
B) Vancomycin
C) Clindamycin
D) Amoxicillin

Answer: B) Vancomycin

Explanation: “Red man syndrome” is a reaction that occurs with rapid infusion of vancomycin, causing flushing, rash, and hypotension.

Which class of drugs is used to treat fungal infections like ringworm and athlete’s foot?

A) Macrolides
B) Antifungals (Azoles, Allylamines)
C) Tetracyclines
D) Antivirals

Answer: B) Antifungals (Azoles, Allylamines)

Explanation: Azoles (like fluconazole) and allylamines (like terbinafine) are commonly used to treat superficial fungal infections.

What is the mechanism of action of itraconazole?

Answer: Itraconazole inhibits the enzyme lanosterol 14α-demethylase, which is involved in the synthesis of ergosterol, a key component of the fungal cell membrane.

Explanation: Without ergosterol, the integrity of the fungal cell membrane is compromised, leading to cell death or inhibition of growth.

Which of the following is a common side effect of rifampin?

A) Hypoglycemia
B) Red-orange discoloration of urine
C) Hyperkalemia
D) Photosensitivity

Answer: B) Red-orange discoloration of urine

Explanation: Rifampin is known to cause a harmless red-orange discoloration of urine, sweat, and tears.

Which of the following antiviral drugs is used to treat cytomegalovirus (CMV) infections?

A) Acyclovir
B) Valacyclovir
C) Ganciclovir
D) Oseltamivir

Answer: C) Ganciclovir

Explanation: Ganciclovir is specifically used for treating CMV infections, particularly in immunocompromised patients.

Which of the following antibiotics is considered a “last-line” treatment for multidrug-resistant tuberculosis (MDR-TB)?

A) Isoniazid
B) Rifampin
C) Linezolid
D) Ethambutol

Answer: C) Linezolid

Explanation: Linezolid is used as a last-resort treatment for MDR-TB when first-line drugs fail due to resistance.

What is the mechanism of action of metronidazole in treating anaerobic infections?

Answer: Metronidazole is reduced within the cell, forming toxic metabolites that damage the DNA and inhibit its replication.

Explanation: This action is especially effective against anaerobic bacteria and protozoa, which are less capable of neutralizing the toxic metabolites.

Which of the following drugs is used as a prophylactic treatment for malaria in travelers?

A) Albendazole
B) Hydroxychloroquine
C) Rifampin
D) Nitrofurantoin

Answer: B) Hydroxychloroquine

Explanation: Hydroxychloroquine is often used for malaria prophylaxis in areas where malaria is endemic, to prevent infection by Plasmodium species.

Which antibiotic is commonly used for the treatment of community-acquired pneumonia (CAP)?

A) Amoxicillin
B) Vancomycin
C) Linezolid
D) Doxycycline

Answer: A) Amoxicillin

Explanation: Amoxicillin is often used as the first-line treatment for community-acquired pneumonia, especially when Streptococcus pneumoniae is suspected.

Which of the following medications is used to treat cryptococcal meningitis?

A) Fluconazole
B) Rifampin
C) Clindamycin
D) Acyclovir

Answer: A) Fluconazole

Explanation: Fluconazole is an antifungal drug commonly used to treat cryptococcal meningitis, particularly in immunocompromised patients.

What class of drug is used for the treatment of HIV and works by inhibiting the integrase enzyme?

A) Protease inhibitors
B) Reverse transcriptase inhibitors
C) Integrase inhibitors
D) Fusion inhibitors

Answer: C) Integrase inhibitors

Explanation: Integrase inhibitors block the enzyme integrase, which is required for HIV to integrate its genetic material into the host cell’s DNA.

What is the primary action of penicillin antibiotics?

Answer: Penicillin antibiotics inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), which are involved in the final stages of cell wall construction.

Explanation: The inhibition of PBPs prevents the cross-linking of peptidoglycan chains, resulting in a weakened cell wall and bacterial lysis.

Which of the following is a potential side effect of long-term use of corticosteroids in treating infections?

A) Immunosuppression
B) Hyperkalemia
C) Hypoglycemia
D) Hypertension

Answer: A) Immunosuppression

Explanation: Corticosteroids can suppress the immune system, making the body more susceptible to infections and reducing the effectiveness of the body’s immune response.

Which of the following antibiotics is effective against both gram-negative and gram-positive bacteria?

A) Vancomycin
B) Ceftriaxone
C) Penicillin
D) Tetracycline

Answer: B) Ceftriaxone

Explanation: Ceftriaxone is a third-generation cephalosporin that has broad-spectrum activity against both gram-positive and gram-negative bacteria.

Which of the following drugs is used to treat infections caused by Mycobacterium avium complex (MAC) in HIV patients?

A) Azithromycin
B) Levofloxacin
C) Rifampin
D) Isoniazid

Answer: A) Azithromycin

Explanation: Azithromycin is commonly used to treat Mycobacterium avium complex (MAC) infections in patients with HIV, especially those with low CD4 counts.

Which of the following is an example of an antivirals for treating influenza A and B?

A) Oseltamivir
B) Ganciclovir
C) Acyclovir
D) Amantadine

Answer: A) Oseltamivir

Explanation: Oseltamivir is a neuraminidase inhibitor that prevents the release of new influenza virus particles from infected cells.

What is the mechanism of action of the antifungal drug amphotericin B?

Answer: Amphotericin B binds to ergosterol, a component of fungal cell membranes, forming pores that disrupt membrane integrity and lead to cell death.

Explanation: The action of amphotericin B is selective for fungal cells because they contain ergosterol, which is absent in human cell membranes.

Which of the following antibiotics is used primarily to treat Clostridium difficile infection (CDI)?

A) Vancomycin
B) Amoxicillin
C) Erythromycin
D) Levofloxacin

Answer: A) Vancomycin

Explanation: Vancomycin, when administered orally, is the treatment of choice for moderate to severe Clostridium difficile infection.

Which of the following is an important side effect of using tetracyclines in children?

A) Tooth discoloration
B) Nephrotoxicity
C) Seizures
D) Liver toxicity

Answer: A) Tooth discoloration

Explanation: Tetracyclines can bind to calcium in developing teeth and cause permanent discoloration, which is why they are avoided in young children and pregnant women.

Which of the following is the first-line treatment for latent tuberculosis infection?

A) Rifampin
B) Isoniazid
C) Pyrazinamide
D) Ethambutol

Answer: B) Isoniazid

Explanation: Isoniazid is the primary drug used for latent tuberculosis treatment because it effectively kills dormant Mycobacterium tuberculosis bacteria.

Which of the following medications is most commonly used for the treatment of herpes zoster (shingles)?

A) Acyclovir
B) Methotrexate
C) Oseltamivir
D) Rifampin

Answer: A) Acyclovir

Explanation: Acyclovir is an antiviral medication that inhibits viral DNA replication and is effective in treating herpes zoster.

Which of the following is an example of a second-generation cephalosporin?

A) Cefepime
B) Cefuroxime
C) Ceftriaxone
D) Cephalexin

Answer: B) Cefuroxime

Explanation: Cefuroxime is a second-generation cephalosporin that has increased activity against gram-negative bacteria compared to first-generation cephalosporins.