CHapter 7 - Pharm, Antibacterial Drugs That Disrupt the Bacterial Cell Wall

LEARNING OBJECTIVES

  • Explain the uses, general drug actions, and general adverse reactions, contraindications, precautions, and interactions of antibacterial drugs that disrupt bacterial cell walls.

  • Distinguish important pre-administration and ongoing assessment activities the nurse should perform on the client taking an antibacterial drug that disrupts bacterial cell walls.

  • List nursing diagnoses particular to a client taking an antibacterial drug that disrupts bacterial cell walls.

  • Discuss hypersensitivity reactions as they relate to antibiotic therapy.

  • Examine ways to promote optimal response to therapy, nursing actions to minimize adverse effects, and important points to keep in mind when educating clients about the use of antibacterial drugs that disrupt bacterial cell walls.

  • SLOs: Nursing Judgment, Safety, EBP and Professional Behavior

ANTIBIOTICS THAT DISRUPT THE CELL WALL

  • Human cells: Have cell membranes.

  • Bacterial cells: Have cell walls.

  • Antibiotics that interfere with cell wall synthesis and cause bacterial cell death include:

    • Penicillins

    • Cephalosporins

    • Carbapenems

    • Vancomycin

RESISTANCE TO DRUGS

  • Bacterial resistance: Some bacteria develop the ability to produce substances that inactivate or destroy antibiotics.

  • Drug resistance becomes an issue when:

    • Antibiotics are regularly used by a client.

    • A group of people lives in close proximity.

    • Bacteria are either naturally resistant or develop acquired resistance (e.g., MRSA).

    • Emergence of new resistance strains associated with bacteria having both natural and acquired resistance abilities.

ANTIBIOTIC STEWARDSHIP

Box 7.1: Ten Commandments of Antibiotic Use

  1. Teach clients to manage nonbacterial infections without drugs.

  2. Know the bacteria, treat it specifically.

  3. Treat for effectiveness and shorten the course, if appropriate.

  4. Communicate with clients to increase adherence.

  5. Use a combination of drugs only in specific situations.

  6. Substitute only when an equivalent product is available.

  7. Educate to prevent self-prescription.

  8. Follow evidence-based guidelines.

  9. Use laboratory results correctly to prescribe.

  10. Research and understand local trends and limits.

    • Adapted from Levy-Hara, G., et al. (2011). Ten commandments for the appropriate use of antibiotics by the practicing physician in an outpatient setting. Front Microbiology, 2, 230.

PENICILLINS—ACTIONS

  • Characteristics: Group of antibiotics targeting susceptible pathogens.

  • Action: Interferes with cell wall synthesis.

  • Classification: There are four groups of penicillins:

    • Natural penicillins

    • Penicillinase-resistant penicillins

    • Aminopenicillins

    • Extended-spectrum penicillins

  • Broader spectrum penicillins and penicillin-lactamase-inhibitor combinations.

PENICILLINS—USES

  • Used against various infectious diseases including:

    • Urinary tract infections

    • Septicemia

    • Meningitis

    • Intra-abdominal infections

    • Sexually transmitted infections (syphilis)

    • Pneumonia and other respiratory infections

    • Soft tissue infections and injuries

  • Used as initial therapy for any suspected staphylococcal infection.

  • Prophylaxis:

    • Potential secondary bacterial infection.

    • High-risk clients (e.g., prior to dental, oral, or respiratory procedures).

    • Ongoing for those with rheumatic fever or chronic ear infections.

PENICILLINS—ADVERSE REACTIONS

Common Gastrointestinal System Reactions:

  • Glossitis (inflammation of the tongue)

  • Stomatitis (inflammation of the mouth)

  • Dry mouth

  • Gastritis

  • Nausea and vomiting

  • Diarrhea and abdominal pain

Other Common Reactions:

  • Pain at injection site (IM)

  • Phlebitis (IV)

Hypersensitivity Reactions:

  • Anaphylactic shock

  • Cross-sensitivity with cephalosporins

  • Other severe reactions include:

    • Anemia

    • Thrombocytopenia

    • Leukopenia

    • Bone marrow depression

PENICILLINS—CONTRAINDICATIONS

  • Caution: Penicillins should not be administered in clients with:

    • Hypersensitivity to penicillins or cephalosporins.

    • Renal disease

    • Asthma

    • Bleeding disorders

    • Gastrointestinal disease

    • Pregnancy (category C)

    • Lactation (diarrhea or candidiasis in the infant)

    • Any indication of sensitivity

PENICILLINS—INTERACTIONS

Interacting Drugs and Their Common Use:

  1. Oral contraceptives (with estrogen)

    • Common use: Contraception

    • Effect of Interaction: Decreased effectiveness of contraceptive agent with ampicillin or penicillin V.

  2. Tetracyclines

    • Common use: Anti-infective

    • Result: Decreased effectiveness of penicillins.

  3. Anticoagulants

    • Common use: Prevent blood clots

    • Result: Increased bleeding risks (especially with large doses of penicillins).

  4. Beta-adrenergic blocking drugs

    • Common use: Blood pressure control and heart problems

    • Effect of Interaction: May increase the risk for an anaphylactic reaction.

SUMMARY DRUG TABLE: SULFONAMIDES

  • Antibacterial Drugs That Disrupt Bacterial Cell Wall Synthesis:

    • Generic Name: Penicillins

    • Narrow-Spectrum Penicillins

    • Trade Name: penicillin G (aqueous)

    • Uses: Streptococcal infections, syphilis; prophylaxis of rheumatic fever

    • Adverse Reactions: Same as penicillin G

    • Dosage: Up to 20-30 million units/day IV or IM

  • Additional formulations and adverse effects are outlined per drug/brand.

CEPHALOSPORINS—ACTIONS

  • Characteristics: Bactericidal with a beta-lactam ring targeting the bacterial cell wall making it unstable to kill the bacteria.

  • Classification: Divided into first-, second-, third-, fourth-, and fifth-generation drugs. As the generations progress:

    • Increased sensitivity to gram-negative microorganisms.

    • Decreased sensitivity to gram-positive microorganisms.

    • Fifth generation is broad spectrum—effective against MRSA.

CEPHALOSPORINS—USES

  • Used to treat various infections including:

    • Respiratory infections

    • Otitis media (middle ear infection)

    • Bone/joint infections

    • Complicated intra-abdominal or genitourinary tract infections

    • Prophylactically:

    • From sexual assault

    • Throughout the perioperative period.

CEPHALOSPORINS—ADVERSE REACTIONS

Gastrointestinal System Reactions:

  • Nausea

  • Vomiting

  • Diarrhea

Other Reactions:

  • Headache

  • Dizziness

  • Malaise

  • Heartburn

  • Fever

  • Nephrotoxicity

  • Aplastic anemia

  • Toxic epidermal necrolysis

  • Positive direct Coombs test (specifically with cefepime).

NURSING ALERT: CEPHALOSPORINS—ADVERSE REACTIONS

  • Allergy: Approximately 10% of people allergic to penicillin are also allergic to cephalosporins.

  • Injection reactions: Pain and tenderness when given IM; phlebitis or thrombophlebitis when given IV; potential for bacterial or fungal superinfection.

CEPHALOSPORINS—CONTRAINDICATIONS

  • Cephalosporins should not be administered in clients with:

    • History of allergies to cephalosporins.

  • Use cautiously in clients with:

    • Renal disease

    • Hepatic impairment

    • Bleeding disorders

    • Pregnancy (category B)

    • Known penicillin allergy.

CEPHALOSPORINS—INTERACTIONS

Interacting Drugs and Their Common Use:

  1. Aminoglycosides

    • Common use: Anti-infective

    • Effect of Interaction: Increases risk for nephrotoxicity.

  2. Oral Anticoagulants

    • Common use: Blood thinner

    • Effect of Interaction: Increased risk for bleeding.

CEPHALOSPORINS—INTERACTIONS

Interacting Drugs and Their Common Use:

  1. Aminoglycosides

    • Common use: Anti-infective

    • Effect of Interaction: Increases risk for nephrotoxicity.

  2. Oral Anticoagulants

    • Common use: Blood thinner

    • Effect of Interaction: Increased risk for bleeding.

  3. Loop Diuretics

    • Common use: Used for diuresis and edema management.

    • Effect: Generally enhance the cephalosporin blood level by reducing renal excretion, which can lead to increased risk of toxicity.

  4. Probenecid

    • Common use: Used for gout pain (to decrease uric acid levels); also used to prolong antibiotic action.

    • Effect of Interaction: Significantly increases and prolongs the concentration of cephalosporins in the blood by competitively inhibiting renal tubular secretion of the antibiotic.

  1. Probenecid

    • Common use: Used for gout pain.

NURSING ALERT: CEPHALOSPORINS—CONTRAINDICATIONS

  • Alcohol contraindication: Cephalosporins should not be taken with alcohol due to risk of a disulfiram-like reaction occurring if alcohol is consumed within 72 hours.

    • Symptoms: flushing, throbbing, respiratory problems, vomiting, sweating, chest pain, hypotension.

    • Severe reactions may include dysrhythmias and unconsciousness.

LISTING OF CEPHALOSPORINS BY GENERATION

First-Generation Cephalosporins

  • cefadroxil:
    Uses: Strep EENT, urinary infections, SSTIs.
    Adverse effects: Nausea, diarrhea.

  • ceFAZolin (Ancef):
    Uses: Multiple bacterial infections, perioperative prophylaxis.
    Adverse effects: Same as cefadroxil.

Second-Generation Cephalosporins

  • cefaclor:
    Uses: Respiratory, EENT, SSTI infections.
    Adverse effects: Nausea, diarrhea, headache, rhinitis, vaginitis.

  • cefuroxime:
    Uses: Lyme disease, respiratory infections, GU, SSTI infections.

Third-Generation Cephalosporins

  • cefdinir:
    Uses: Respiratory, EENT, SSTI infections.
    Adverse effects: Nausea, diarrhea, vaginitis.

Fourth-Generation Cephalosporins

  • cefepime (Maxipime):
    Uses: UTI, SSTI, febrile neutropenia.
    Adverse effects: Injection phlebitis.

Fifth-Generation Cephalosporins

  • ceftaroline (Teflaro):
    Uses: MRSA, acute bacterial skin/soft tissue infections, pneumonia.
    Adverse effects: Nausea, diarrhea, rash, pruritus.

CARBAPENEMS AND MISCELLANEOUS BACTERIAL CELL WALL INHIBITORS

  • General Overview: These drugs represent a broad-spectrum class of antibiotics (carbapenems) and other agents like glycopeptides (vancomycin) that target the structural integrity of the bacterial cell wall, leading to osmotic lysis and cell death.

ACTIONS

  • Carbapenems (e.g., Imipenem, Meropenem):

    • Mechanism: These are bactericidal drugs that contain a beta-lactam ring. They inhibit synthesis of the bacterial cell wall by binding to penicillin-binding proteins (PBPs).

    • Resistence: They are particularly notable for being highly resistant to most beta-lactamase enzymes produced by bacteria.

  • Vancomycin (Glycopeptide):

    • Mechanism: Inhibits bacterial cell wall synthesis at a site different from penicillins; it binds to the D-alanyl-D-alanine portion of the cell wall precursor. This prevents the cross-linking of the peptidoglycan layer.

    • Permeability: It also increases the cytoplasmic membrane permeability of the bacteria.

  • Monobactam (Aztreonam):

    • Mechanism: Contains a unique monocyclic beta-lactam nucleus; it specifically targets aerobic gram-negative bacteria by inhibiting cell wall synthesis.

USES

  • Carbapenems:

    • Meropenem: Preferred for serious intra-abdominal infections and bacterial meningitis due to its penetration into the CSF.

    • Imipenem-cilastatin: The cilastatin component prevents the breakdown of imipenem by the kidneys (renal dehydropeptidase I). Used for endocarditis, septicemia, and complex UTIs.

    • Ertapenem: Often used for community-acquired pneumonia and acute pelvic infections.

  • Lipoglycopeptides (Telavancin, Oritavancin, Dalbavancin):

    • Indicated for complicated skin and skin structure infections (cSSSI).

  • Vancomycin:

    • Considered the "gold standard" for treating Methicillin-resistant Staphylococcus aureus (MRSA).

    • Oral Administration: Only used for treating Clostridioides difficile (C. diff) and pseudomembranous colitis, as it is not absorbed systemically from the GI tract.

ADVERSE REACTIONS

  • Gastrointestinal System: High incidence of nausea, vomiting, and diarrhea. Risk of C. diff associated diarrhea (CDAD) due to alteration of normal flora.

  • Nephrotoxicity and Ototoxicity:

    • Primarily associated with Vancomycin. Requires monitoring of "trough" levels (target usually 10-20 \text{ mcg/mL} depending on infection severity).

  • Infusion-Related Reactions:

    • Red Man Syndrome (Vancomycin): Result of rapid IV infusion. Symptoms include flushing, a red rash on the face, neck, and upper torso, and hypotension caused by histamine release.

  • Central Nervous System:

    • Carbapenems (especially Imipenem) may lower the seizure threshold, leading to convulsions.

  • Local Site Reactions: Abscess development, phlebitis, or tissue sloughing at the injection site (extravasation risk).

CONTRAINDICATIONS & PRECAUTIONS

  • Contraindications:

    • Clients with a history of anaphylactic reactions to cephalosporins or penicillins (potential cross-sensitivity).

    • Telavancin: Contraindicated in pregnancy (Category C/D) due to potential fetal harm.

  • Precautions:

    • Central Nervous System Disorders: Use with extreme caution in clients with existing seizure disorders.

    • Renal Impairment: Dosage adjustments are mandatory because these drugs are primarily excreted through the kidneys.

INTERACTIONS

  • Probenecid: Competitively inhibits the renal tubular secretion of carbapenems, resulting in higher and prolonged serum levels of the antibiotic.

  • Anticoagulants: Can enhance the effects of warfarin, significantly increasing the risk of bleeding (monitor PT/INR levels).

  • Aminoglycosides: When used concurrently with Vancomycin, there is an additive or synergistic risk for nephrotoxicity and ototoxicity.

NURSING CONSIDERATIONS

  • Administration:

    • Vancomycin must be infused over at least 60 minutes to prevent Red Man Syndrome.

    • Dilute IV solutions properly and rotate injection sites to prevent phlebitis.

  • Monitoring:

    • Monitor BUN and Creatinine levels regularly to assess for nephrotoxicity.

    • Assess for tinnitus or hearing loss (ototoxicity signs).

MISCELLANEOUS DRUGS THAT INHIBIT BACTERIAL CELL WALL SYNTHESIS

  • Aztreonam (Azactam):

    • Indicated for E. coli infections.

    • Adverse effects: Nausea, vomiting, diarrhea, rash.

    • Dosage: 1-2 g every 8-12 hr, max 8 g/day.

  • Dalbavancin (Dalvance):

    • Indicated for acute bacterial skin infections.

    • Dosage: 1000 mg IV initially; follow with 500 mg IV after one week.

VANCOMYCIN (Vancocin)

  • Used for serious gram-positive infections not responding to other treatments.

  • Adverse effects: Nausea, chills, fever, urticaria, sudden blood pressure drops, nephrotoxicity, ototoxicity.

  • Dosage: Single 1200 mg IV dose or 10 mg/kg IV daily for 4-7 days.

NURSING PROCESS FOR CLIENT RECEIVING ANTIBACTERIAL DRUGS THAT DISRUPT THE BACTERIAL CELL WALL

PRE-ADMINISTRATION ASSESSMENT

Objective Data:

  • General appearance (paleness, flushing)

  • Vital signs

  • Description of infection (site, type, drainage, pain, redness, inflammation)

  • Review results of tests (e.g., C&S, liver or kidney function tests)

Subjective Data:

  • Current symptoms (malaise, fatigue, pain)

  • Allergy history (especially to penicillin or cephalosporin)

  • Drug history

  • History of medical/surgical treatments.

ONGOING ASSESSMENT

  • Observe for relief/intensification of symptoms.

  • Monitor temperature and appetite.

  • Assess appearance/amount of drainage.

  • Report any worsening infection or adverse reactions to health care provider.

  • Regularly check lab reports, including additional C&S tests.

  • Monitor for diarrhea, superinfections, and signs of hypersensitivity.

PLANNING

  • Expected outcomes may include:

    • Optimal response to drug therapy.

    • Needs related to management of adverse drug reactions met.

    • Confidence in understanding prescribed treatment regimen.

IMPLEMENTATION

  • Maintain adequate blood levels of drug; administer antibiotics based on C&S results.

  • Administer oral penicillins on an empty stomach or per meal guidelines as specified.

  • Follow reconstitution and administration protocols for IV antibiotics.

NURSING DIAGNOSES

  1. Altered Skin Integrity

    • Frequent skin care methods and monitoring for rashes or hives.

    • Administer prescribed medications for hypersensitivity reactions.

  2. Risk for Impaired Gas Exchange

    • Monitor for major hypersensitivity reactions with immediate treatment protocols ready.

  3. Impaired Urinary Elimination

    • Monitor signs of nephrotoxicity, measuring intake/outflow, and notify of decreased outputs.

  4. Impaired Oral Mucous Membranes

    • Daily mouth inspections for glossitis or sore tongues and provide mouth care.

  5. Impaired Comfort: Increased Fever

    • Monitor vitals every 4 hours, managing fever with antipyretics as needed.

EDUCATION FOR CLIENT AND FAMILY

  • Develop a comprehensive teaching plan to ensure understanding of drugs and treatment regimens.

    • Advise specific strategies for managing potential adverse effects and compliance with the therapeutic regimen.

    • Instruct on the significance of dietary choices and potential interactions with medications such as oral contraceptives.

EVALUATION

  • Consider:

    • Evaluating the therapeutic response and control of infection.

    • Reviewing skin integrity, gas exchange adequacy, urinary elimination, bowel movements, and client understanding of drug regimens.