Hesi antiinfectives ATB

A comprehensive set of Q&A flashcards covering cell physiology basics, mechanisms of anti-infectives, resistance, treatment strategies, and major antibiotic classes (aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, penicillins, sulfonamides, tetracyclines).

What is the role of the lipid bilayer in the cell membrane?

It provides the basic structure of the membrane and contributes to selective permeability, separating the interior from the exterior.

What identifies self-cells in the immune system?

Histocompatibility antigens identify self-cells.

What are receptor sites in the cell membrane?

Specific locations on the membrane that bind signaling molecules to trigger cellular responses.

What are channels (Na, K, Ca, etc.) in the cell membrane?

Proteins that allow selective passage of ions across the membrane, facilitating electrical signals and homeostasis.

Which organelle makes ATP?

Mitochondria.

Which organelle contains digestive enzymes?

Lysosomes.

What do chemotherapeutic drugs target?

Both invading organisms (bacteria, viruses, parasites, protozoa, fungi) and abnormal cells (neoplasms/cancers).

Name the invading organisms mentioned that are targets of anti-infectives.

Bacteria, viruses, parasites, protozoa, fungi.

What is the primary goal of anti-infective agents?

Destroy invading organisms and interrupt their function so they cannot reproduce, causing cell death, while minimizing harm to host cells.

What is one mechanism by which some drugs destroy invading organisms?

Destroy the cell wall of the invading organism (e.g., penicillins) or inhibit cell wall synthesis.

What mechanism prevents the invading organism from using essential substances?

Inhibit the organism’s use of substances it needs (e.g., sulfonamides inhibiting folic acid synthesis).

Which mechanism interrupts protein synthesis?

Protein synthesis is interrupted by aminoglycosides and related drugs.

Which mechanism interrupts DNA synthesis?

DNA synthesis is interrupted by fluoroquinolones.

Which mechanism alters cell membrane permeability to cause cell death?

Some antifungals, certain antibiotics, and antiprotozoals alter membrane permeability.

Differentiate bactericidal/fungicidal from bacteriostatic/fungistatic action.

Bactericidal/fungicidal drugs kill the organism; bacteriostatic/fungistatic drugs inhibit growth and reproduction.

What is narrow spectrum versus broad spectrum activity?

Narrow spectrum: targets specific organisms; broad spectrum: affects a wide variety of microorganisms.

Can anti-infectives be used without any effect on host cells?

No. All anti-infectives can affect host cells to some extent.

Who is at higher risk when using anti-infectives?

Immunocompromised patients (elderly, infants, transplant patients, cancer patients, HIV/AIDS, malnutrition).

How can pathogens develop resistance to anti-infectives?

Enzymes that deactivate the drug (e.g., penicillinase), reduced drug entry, altered binding sites, or production of antagonists.

Give an example of enzymatic drug deactivation leading to resistance.

Penicillinase deactivating penicillin.

What is one way pathogens prevent drug entry?

Altering cell entry mechanisms or changing porins to block drug uptake.

How can pathogens alter drug targets to resist therapy?

Altering binding sites so the drug no longer binds effectively.

What is another resistance mechanism involving chemical interactions?

Producing chemicals that antagonize the drug.

What dosing strategy helps prevent resistance?

Consistent around-the-clock dosing (e.g., q8h) rather than irregular dosing (tid).

Should antibiotics be used for viral infections?

No.

What should patients do with prescribed antibiotics?

Take as prescribed, complete the full course, and do not stop early.

What is the first step in treating systemic infections?

Identify the pathogen via culture (blood, urine, wound, etc.).

What is the second step in treating systemic infections?

Perform sensitivity testing; may start broad-spectrum antibiotic first, then switch to narrow after results.

What is the third step in treating systemic infections?

Consider possible combination therapy to improve efficacy and delay resistance.

Name a key toxicity risk associated with many anti-infectives related to the kidneys.

Nephrotoxicity (kidney damage).

Name a key toxicity risk associated with anti-infectives related to the liver.

Hepatotoxicity (liver damage, hepatitis, or liver failure).

What nervous system toxicity can occur with certain anti-infectives like aminoglycosides?

Neurotoxicity, including effects on nerve function.

Which cranial nerve can be affected by aminoglycosides, leading to dizziness and hearing loss?

8th cranial nerve (vestibulocochlear nerve).

What are common entry routes for bacteria to cause infection?

Respiratory tract, GI tract, and skin.

What signs are indicative of inflammation and infection?

Loss of function, fatigue, redness, swelling, heat/fever, and pain.

What distinguishes Gram-positive from Gram-negative bacteria in terms of typical infection sites?

Gram-positive: often respiratory/soft tissue infections (e.g., Streptococcus). Gram-negative: often GI/GU infections (e.g., Escherichia coli).

What does ‘selective toxicity’ mean in antibiotic use?

Destroying bacteria while causing minimal damage to the host.

When lab results are pending, why might broad-spectrum antibiotics be used?

To cover a wide range of possible pathogens until results identify the exact organism.

List four aminoglycosides.

Amikacin, gentamicin, kanamycin, neomycin, streptomycin, tobramycin.

What is a key warning for fluoroquinolones regarding tendons?

Black box warning: risk of tendinitis and tendon rupture, especially in age groups under 18 and over 60.

Name a major interaction concern with fluoroquinolones and iron/mineral supplements/antacids.

Fluoroquinolones chelate with iron, minerals, and antacids, reducing absorption; separate dosing.

What is a common adverse GI effect associated with many antibiotics?

Nausea, vomiting, diarrhea, abdominal discomfort.

Which two major drug classes should be used cautiously together due to nephrotoxicity risk?

Aminoglycosides and other nephrotoxic agents (e.g., certain cephalosporins and diuretics) when used together.

What are four generations of cephalosporins generally known for?

1st generation (e.g., cephalexin), 2nd generation (e.g., cefoxitin), 3rd generation (e.g., cefdinir/ceftriaxone), 4th generation (e.g., cefepime) with MRSA activity noted in some 4th-gen agents.

Why are cephalosporins contraindicated for some patients?

Allergy to cephalosporins or penicillin due to potential cross-sensitivity.

Give an example of a penicillin-named drug and its category.

Penicillin G (various salts) and penicillin V; also Extended Spectrum PCN like amoxicillin/ampicillin; Penicillinase-resistant like nafcillin/oxacillin.

What is a major consideration when taking penicillins regarding administration?

Some penicillins require absorption on an empty stomach with a full glass of water for better absorption.

Name a common adverse effect and a key interaction for penicillins.

GI disturbances; possible superinfections; interactions include decreased effectiveness with tetracyclines and inactivation with simultaneous aminoglycoside administration.

What is a major concern with sulfonamides during pregnancy and lactation?

Teratogenic effects and kernicterus risk in newborns; avoid in pregnancy/lactation.

Which systems are commonly affected by tetracyclines and what special dietary guidance exists?

GI distress, hepatotoxicity, and skeletal/tooth effects; avoid dairy and iron near dosing; take on an empty stomach or as directed; absorption affected by food.

What is a notable use of tetracyclines beyond infections?

Treatment of acne.