Antibacterial & Antimycobacterial Therapy – Lecture Review

A comprehensive set of question-and-answer flashcards covering key concepts, drug prototypes, mechanisms, adverse effects, nursing considerations, laboratory monitoring, and patient teaching points from the antibacterial and antimycobacterial lecture.

What is the difference between a bactericidal and a bacteriostatic drug?

Bactericidal drugs kill bacteria directly (e.g., lyse the cell wall); bacteriostatic drugs inhibit growth so the immune system can eliminate the organism.

Name four major ways antibacterials work against microbes.

1) Inhibit cell-wall synthesis 2) Inhibit DNA replication/cell division 3) Inhibit folic-acid synthesis 4) Disrupt protein synthesis or other essential processes.

How do narrow-spectrum and broad-spectrum antibiotics differ?

Narrow-spectrum agents act against a limited group of organisms; broad-spectrum agents treat a wide variety of organisms.

Why must a culture & sensitivity (C&S) be obtained before starting antibiotics?

To identify the organism and determine which drugs it is sensitive or resistant to, ensuring appropriate therapy.

List three key strategies for preventing antibiotic resistance.

1) Use antibiotics only for pathogens known to be sensitive 2) Give adequate dose & full duration 3) Avoid indiscriminate/viral use.

Define a superinfection.

A new infection that appears during or after treatment of the original infection—often due to disruption of normal flora.

Which fungal infection commonly occurs as a superinfection and how is oral thrush treated?

Candidiasis (thrush); treated with nystatin "swish & swallow".

What hallmark symptom helps nurses recognize C. difficile infection?

Profuse, foul-smelling watery diarrhea (often unforgettable odor).

During anaphylaxis, which nursing priority comes first?

Establish/maintain airway and provide oxygen.

Which labs are routinely checked for kidney function when patients receive nephrotoxic antibiotics?

BUN and creatinine.

Name three primary liver-function tests a nurse may monitor with hepatotoxic drugs.

AST (and often ALT), albumin, bilirubin.

Which coagulation tests are reviewed when an antibiotic increases bleeding risk?

Platelet count, PT/INR, and PTT.

What is the prototype penicillin and one common indication?

Amoxicillin; used for ear, throat, or urinary infections.

Which teaching is essential concerning penicillins and oral contraceptives?

Penicillins can decrease contraceptive efficacy—use backup birth control.

What cephalosporin prototype can cause a disulfiram-like reaction with alcohol?

Cephalexin (and other cephalosporins).

Why should cephalosporins be infused slowly IV?

Fast infusion can cause thrombophlebitis; slow infusion reduces vein irritation.

Why must nurses ask about penicillin allergy before giving a cephalosporin?

Because of possible cross-sensitivity; many penicillin-allergic patients also react to cephalosporins.

Name the monobactam prototype and a key IV consideration.

Aztreonam; it is incompatible with many drugs—use a separate IV line and infuse slowly.

Carbapenems (e.g., imipenem-cilastatin) are administered by which routes?

IM or IV only (not absorbed orally).

Which drug is first-line for MRSA and oral therapy for C. diff?

Vancomycin (IV for MRSA; PO for C. difficile).

What is Red-Man Syndrome and how is it prevented?

Flushing, rash, hypotension from rapid vancomycin infusion; prevent by diluting and infusing over ≥60 minutes.

Which serum levels are checked with vancomycin therapy?

Peak and trough levels (especially trough before next dose).

Why are tetracyclines contraindicated in children under 8 and pregnant women?

They discolor teeth and inhibit bone growth in developing children/fetuses.

What sun-related precaution must patients take with tetracyclines?

Use sunscreen/protective clothing due to photosensitivity.

Which serious cardiac effect can erythromycin (a macrolide) produce?

Prolonged QT interval leading to ventricular dysrhythmias.

List two key toxicities to monitor with gentamicin.

Ototoxicity (hearing loss, tinnitus) and nephrotoxicity (elevated BUN/creatinine, low urine output).

Why is gentamicin not given orally?

It is not absorbed from the GI tract; given IV, IM, topical, ophthalmic, or intrathecal.

When are gentamicin peak and trough levels drawn?

Peak: ~30 minutes after infusion ends; Trough: 1 hour before next dose.

Which fluoroquinolone may rupture the Achilles tendon, especially in adults over 60?

Ciprofloxacin (Cipro).

Name two teaching points to reduce ciprofloxacin side-effects.

1) Limit caffeine to reduce CNS symptoms 2) Avoid sun exposure; use sunscreen for photosensitivity.

Which life-threatening skin reaction is associated with TMP-SMX (a sulfonamide)?

Stevens-Johnson Syndrome.

Why must patients on TMP-SMX drink plenty of water?

To prevent renal crystalluria and damage—encourage 1.5–2 L/day fluid intake.

Which UTI-specific drug darkens urine and should not be opened or crushed?

Nitrofurantoin.

What are two major adverse effects of isoniazid (INH) for TB?

Hepatotoxicity and peripheral neuropathy.

How do rifampin’s harmless body-fluid changes appear and what eye-wear advice is given?

Turns urine, sweat, saliva, tears red-orange; may stain contact lenses—consider daily disposables.

Which two TB drugs can reduce effectiveness of oral contraceptives?

Rifampin and isoniazid (backup birth control advised).

Which infusion rate prevents Red-Man Syndrome with vancomycin?

At least 60 minutes (or longer) per dose.

What symptoms indicate a disulfiram-like reaction with cephalosporins and alcohol?

Flushing, severe nausea/vomiting, chest pain, hypotension, palpitations—patient feels very ill.

When measuring antibiotic levels, why is the trough most critical for vancomycin?

High troughs predict toxicity; ensure level is low enough before next dose is given.

List the drug classes that inhibit cell-wall synthesis.

Penicillins, cephalosporins, monobactams, carbapenems, and vancomycin.

Which drug class inhibits bacterial DNA replication?

Fluoroquinolones (e.g., ciprofloxacin).

Which two antibiotic classes inhibit folic-acid synthesis?

Sulfonamides (TMP-SMX) and urinary antiseptic nitrofurantoin.

Name two antibiotic classes commonly causing photosensitivity.

Tetracyclines and fluoroquinolones (ciprofloxacin).

What should a nurse suspect if a patient develops watery/bloody diarrhea while on antibiotics?

Possible C. difficile infection—notify provider and consider stopping the drug.

What general contraception advice is given with many antibiotics?

Use an additional non-hormonal method because antibiotics may lower oral contraceptive efficacy.

How can probiotics help during certain antibiotic courses?

They restore normal GI flora and reduce risk of C. difficile and other superinfections.