UNIT 2: ANTI-INFECTIVE & ANTI-INFLAMMATORY

UNIT 2: ANTI-INFECTIVE & ANTI-INFLAMMATORY NURS 220: Pharmacology for Nurses

ANTIBIOTICS

  • Definition: Chemicals that inhibit specific bacteria.

  • Manufacturing Methods:

    • By living microorganisms

    • By synthetic manufacture

    • Through genetic engineering

THERAPEUTIC ACTION OF ANTIBIOTICS (ABX)

  • Actions include:

    • Interference with biosynthesis of bacterial cell wall.

    • Prevention of essential growth: Prevent cells of invading organisms from utilizing substances necessary for their growth.

    • Interference with DNA and protein synthesis: Affects the respective biological functions.

    • Alteration of cell membrane permeability: Allows essential cellular components to leak out.

ANTI-INFECTIVE ACTIVITY

  • Effectiveness:

    • Varies based on the pathogen; some antibiotics are selective, effective for only a few organisms.

    • Bactericidal: Kills bacterial cells.

    • Bacteriostatic: Prevents the reproduction of cells; allows the immune system to work.

BACTERIA CLASSIFICATION

  • Gram Positive: The cell wall retains a stain or resists decolorization.

  • Gram Negative: The cell wall loses a stain.

  • Aerobic: Depends on oxygen for survival.

  • Anaerobic: Does not utilize oxygen.

NARROW VS BROAD SPECTRUM

  • Narrow Spectrum: Effective against only a few microorganisms with very specific pathways or enzymes.

  • Broad Spectrum: Useful in treating a wide variety of infections.

HUMAN IMMUNE RESPONSE

  • Goal of anti-infective therapy: Reduce the population of the invading organism.

  • Toxicity Concerns: Drugs that eliminate all invading pathogens could be toxic to host cells.

  • Immune System Complexity: Involves chemical mediators, leukocytes, lymphocytes, antibodies, and locally released enzymes and chemicals.

RESISTANCE

  • Definition: Natural or acquired ability to adapt to an anti-infective drug, producing cells that are no longer affected by a particular drug.

  • Mechanisms: Bacteria may alter cell wall or enzyme systems (e.g., development of penicillinase in some bacteria that were once sensitive to penicillin).

  • Superinfections: Overgrowth of resistant pathogens (bacteria, fungi, or yeasts) can occur due to antibiotic use.

PREVENTING RESISTANCE

  • Recommendations:

    • Limit the use of antimicrobial agents to treatment of specific sensitive pathogens.

    • Ensure that doses are sufficiently high and the duration is long enough.

    • Avoid indiscriminate use of antibiotics.

TREATMENT OF SYSTEMIC INFECTIONS

  • Process:

    • Identification of the infecting pathogen via culture.

    • Sensitivity Testing: Determines which drugs control the specific microorganism.

    • Combination Therapy:

    • Use smaller doses of each drug, potentially cyclic.

    • Some combinations may exhibit synergistic effects and delay emergence of resistant strains.

PROPHYLAXIS

  • Recommendations for specific populations:

    • Travelers to endemic areas for infections.

    • Patients undergoing GI or GU surgeries.

    • Individuals with known cardiac valve disease, valve replacements, or other conditions needing invasive procedures (e.g., dental).

ADVERSE REACTIONS TO ANTI-INFECTIVE THERAPY

  • Potential manifestations:

    • Kidney damage.

    • Gastrointestinal toxicity.

    • Neurotoxicity.

    • Hypersensitivity reactions.

    • Superinfections.

AMINOGLYCOSIDES

  • Definition: A group of powerful antibiotics for serious infections caused by gram-negative aerobic bacilli.

  • Common Medications:

    • Amikacin

    • Gentamicin

    • Neomycin

    • Streptomycin

    • Tobramycin

AMINOGLYCOSIDES: ACTIONS AND PHARMACOKINETICS

  • Action: Bactericidal; inhibits protein synthesis in susceptible strains of gram-negative bacteria, causing cell death.

  • Pharmacokinetics:

    • Poorly absorbed from GI tract; rapidly absorbed after IM injection, peak levels within 1 hour.

    • Widely distributed throughout the body, crosses placenta, and enters breast milk.

    • Excreted unchanged in urine; average half-life of 2-3 hours; requires functioning kidneys for excretion.

AMINOGLYCOSIDES: CONTRAINDICATIONS AND ADVERSE EFFECTS

  • Contraindications:

    • Known allergies, renal/hepatic disease, hearing loss, active herpes/mycobacterial infection, myasthenia gravis/parkinsonism, lactation.

  • Adverse Effects:

    • Ototoxicity and nephrotoxicity are primary risks.

  • Drug-Drug Interactions:

    • Includes other antibiotics (e.g., penicillins), diuretics, neuromuscular blockers.

NURSING CONSIDERATIONS FOR AMINOGLYCOSIDES

  • Assessment and Monitoring:

    • Renal function: Monitor BUN, creatinine, urine output (risk of nephrotoxicity).

    • Hearing and balance: Assess for tinnitus, hearing loss, dizziness, or vertigo (risk of ototoxicity).

    • Neurologic status: Watch for headache, confusion, neuromuscular blockade, or paresthesias.

    • Infection status: Monitor WBC count, temperature, and infection site for therapeutic response.

LABORATORY MONITORING FOR AMINOGLYCOSIDES

  • Peak and Trough Levels:

    • Obtained to ensure therapeutic range and avoid toxicity.

    • Peak: Measures effectiveness.

    • Trough: Ensures safety to prevent accumulation.

  • Urinalysis: Evidence of nephrotoxicity (e.g., proteinuria, casts, hematuria).

PATIENT SAFETY AND EDUCATION FOR AMINOGLYCOSIDES

  • Hydration: Encourage adequate fluid intake to protect kidneys.

  • Emergency Reporting: Instruct patients to communicate symptoms such as tinnitus, hearing loss, or decreased urination.

  • Avoid Nephrotoxic/Ototoxic Drugs:

    • Includes loop diuretics (e.g., furosemide), other nephrotoxic antibiotics, NSAIDs.

ADMINISTRATION CONSIDERATIONS FOR AMINOGLYCOSIDES

  • Route: Generally IV or IM; poorly absorbed orally (except neomycin for GI decontamination).

  • Compatibility: Do not mix with penicillins in the same IV line as it inactivates aminoglycoside.

  • Timing: Strict adherence to dosing schedule is necessary for effective therapeutic levels.

SPECIAL POPULATIONS CONSIDERATIONS FOR AMINOGLYCOSIDES

  • Elderly and Infants: Increased toxicity risk due to reduced renal clearance.

  • Pregnancy: Use cautiously due to potential fetal ototoxicity.

  • Preexisting Conditions: Increased caution and frequent monitoring for renal/hearing impairment.

BETA LACTAM ANTIBIOTICS

  • Definition: A class of antibiotics characterized by the beta-lactam ring; effective against both gram-positive and gram-negative bacteria.

  • Mechanism: Inhibits synthesis of bacterial cell walls, leading to cell lysis.

  • Examples of Beta Lactam Antibiotics:

    • Penicillins.

    • Cephalosporins.

    • Carbapenems.

  • Common Uses: Treatment for UTI, skin infections, respiratory infections, bone and joint infections, and sepsis.

CARBAPENEMS

  • Definition: New class of broad-spectrum antibiotics effective against both Gram-positive and Gram-negative bacteria.

  • Common Medications:

    • Doripenem (Doribax)

    • Ertapenem (Invanz)

    • Imipenem-cilastatin (Primaxin)

    • Meropenem (Merrem IV)

    • Meropenem-vaborbactam (Vabomere)

CARBAPENEMS: ACTIONS AND PHARMACOKINETICS

  • Action: Bactericidal; inhibits cell membrane synthesis, leading to cell death.

  • Pharmacokinetics:

    • Rapidly absorbed if given IM; reaches peak levels after IV infusion.

    • Widely distributed, but unknown whether they cross the placenta or enter breast milk.

    • Excreted unchanged in the urine; average half-life of 1-4 hours.

CARBAPENEMS: CONTRAINDICATIONS AND ADVERSE EFFECTS

  • Contraindications:

    • Known allergy to carbapenems or beta-lactams; seizure disorders; in meningitis; pregnancy and lactation risks.

  • Adverse Effects:

    • Pseudomembranous colitis; Clostridium difficile diarrhea; nausea and vomiting (risk of dehydration and electrolyte imbalance).

  • Drug-Drug Interactions:

    • Caution with valproic acid and meropenem; may need alternative antibiotics.

CEPHALOSPORINS

  • Definition: Beta-lactam antimicrobials for managing a range of infections from gram-positive and gram-negative bacteria.

  • Structure & Activity: Similar to penicillin.

  • Common Medications: Categories based on generation:

    • First generation: cefadroxil (generic), cephalexin (Keflex).

    • Second generation: cefaclor (Ceclor), cefoxitin (generic), cefprozil (generic), cefuroxime (Zinacef).

    • Third generation: cefdinir (Omnicef), cefotaxime (Claforan), cefpodoxime (generic), ceftazidime (Ceptaz, Tazicef), ceftizoxime (Cefizox), ceftriaxone (Rocephin).

    • Fourth generation: ceftolozane-tazobactam (Zerbaxa).

    • Fifth generation: ceftaroline (Teflaro).

CEPHALOSPORINS: ACTIONS AND PHARMACOKINETICS

  • Action: Interferes with cell wall-building ability of bacteria during division.

  • Pharmacokinetics:

    • Well absorbed from GI tract; metabolized in the liver; excreted in urine.

    • Ability to cross the placenta and enter breast milk (see contraindications).

CEPHALOSPORINS: CONTRAINDICATIONS AND ADVERSE EFFECTS

  • Contraindications: Allergies to cephalosporins or penicillin; renal/hepatic impairment.

  • Adverse Effects: Most significant are GI side effects.

  • Drug-Drug Interactions: Associated with nephrotoxicity (aminoglycosides); interactions with oral anticoagulants, alcohol.

FLUOROQUINOLONES

  • Definition: New synthetic class of antibiotics with a broad spectrum of activity.

  • Common Medications:

    • Ciprofloxacin (Cipro)

    • Delafloxacin (Baxdela)

    • Gemifloxacin (Factive)

    • Levofloxacin (Levaquin)

    • Moxifloxacin (Avelox)

    • Ofloxacin (Ocuflox)

    • Finafloxacin (Xtoro).

FLUOROQUINOLONES: ACTIONS AND PHARMACOKINETICS

  • Action: Bactericidal; interferes with DNA replication in susceptible gram-negative bacteria, preventing cell reproduction.

  • Pharmacokinetics:

    • Absorbed in GI tract; metabolized in the liver; excreted in urine and feces; crosses placenta and enters breast milk.

FLUOROQUINOLONES: WARNINGS AND ADVERSE EFFECTS

  • Common Contraindications: Known allergy, pregnancy, lactating women, and renal dysfunction.

  • Adverse Effects: Headache, dizziness, insomnia, depression.

  • Drug-Drug Interactions: Iron salts, sucralfate, mineral supplements, antacids, quinidine, theophylline, NSAIDs.

PENICILLINS AND PENICILLINASE-RESISTANT ANTIBIOTICS

  • Definition: The first antibiotic introduced for clinical use, primarily effective against Gram-positive bacteria.

  • Common Medications:

    • Penicillin G benzathine (Bicillin L.A., Permapen)

    • Penicillin G potassium (Pfizerpen)

    • Penicillin G procaine

    • Penicillin V (Penicillin-VK)

    • Amoxicillin (Amoxil)

    • Ampicillin.

PENICILLINS AND PENICILLINASE-RESISTANT ANTIBIOTICS: ACTIONS AND PHARMACOKINETICS

  • Action: Bactericidal; interferes with the ability of susceptible bacteria to build their cell walls.

  • Pharmacokinetics:

    • Rapidly absorbed from GI tract; peak levels in 1 hour; excreted unchanged in urine.

    • Also found in breast milk.

PENICILLINS AND PENICILLINASE-RESISTANT ANTIBIOTICS: CONTRAINDICATIONS AND ADVERSE EFFECTS

  • Contraindications: Allergies to penicillin or cephalosporins; renal disease; cautious use in pregnancy/lactation.

  • Adverse Effects: Notably GI tract issues.

  • Drug-Drug Interactions: Includes tetracyclines and parenteral aminoglycosides.

NATURAL PENICILLINS

  • Examples:

    • Penicillin G Benzathine: Treatment for syphilis.

    • Penicillin G Potassium:

    • Penicillin G Procaine: For moderately severe infections.

    • Penicillin V: For prophylaxis in bacterial endocarditis, Lyme disease, UTI.

AMINOPENICILLINS

  • Examples:

    • Amoxicillin: Broad-spectrum for adults and children.

    • Amoxicillin-Clavulanate: For lower respiratory tract infections, otitis media, skin infections, and UTI.

    • Ampicillin: Generally broad-spectrum.

    • Ampicillin-Sulbactam (Unasyn): Treats skin, intra-abdominal, and gynecologic infections.

PENICILLINASE-RESISTANT (ANTISTAPHYLOCOCCAL)

  • Common Medications:

    • Dicloxacillin

    • Nafcillin

    • Oxacillin.

ANTI-PSEUDOMONAL PENICILLINS

  • Examples:

    • Piperacillin: Effective against intra-abdominal, gynecologic, lower respiratory tract, skin, bone, and joint infections.

    • Piperacillin-Tazobactam: Used for intra-abdominal infections, nosocomial pneumonia, skin, and pelvic infections.

SULFONAMIDES

  • Definition: Drugs that inhibit folic acid synthesis.

  • Common Medications:

    • Sulfadiazine

    • Sulfasalazine (Azulfidine)

    • Cotrimoxazole (Septra, Bactrim).

  • Mechanism of Action: Bacteriostatic; block para-aminobenzoic acid to prevent the synthesis of folic acid in susceptible bacteria.

  • Indications:

    • Used for treating infections caused by gram-negative and gram-positive bacteria.

SULFONAMIDES: PHARMACOKINETICS

  • Pharmacokinetics:

    • Well absorbed from the GI tract; metabolized in the liver; excreted in urine; teratogenic.

  • Contraindications: Known allergy to sulfonamides, thiazide diuretics, and during pregnancy.

  • Adverse Effects: Include GI symptoms and renal effects related to drug filtration.

  • Drug-Drug Interactions: Can affect various other medications including those affecting blood sugar levels.

SULFONAMIDE USE

  • Indicated for:

    • UTI.

    • Exacerbation of chronic bronchitis in adults.

    • Otitis media in children.

    • Traveler’s diarrhea in adults.

    • Pneumocystis jirovecci pneumonia.

TETRACYCLINES

  • Definition: Developed from semisynthetic antibiotics based on common soil mold; known for broad-spectrum activity.

  • Common Medications:

    • Tetracycline

    • Demeclocycline

    • Doxycycline

    • Minocycline.

TETRACYCLINES: ACTIONS AND PHARMACOKINETICS

  • Action: Bacteriostatic; inhibits protein synthesis, thus preventing cell replication.

  • Indications: Effective for treating acne when penicillin is contraindicated.

  • Pharmacokinetics:

    • Well absorbed in the GI tract; concentrated in the liver; excreted unchanged; crosses placenta and breast milk.

TETRACYCLINES: CONTRAINDICATIONS AND ADVERSE EFFECTS

  • Contraindications: Known allergy to tetracyclines or tartrazine, pregnancy, lactation, renal or hepatic dysfunction.

  • Adverse Effects: May cause GI disturbances, teeth/bone damage; notable drug-to-drug interactions include penicillin G, oral contraceptives.

ANTIMYCOBACTERIALS

  • Definition: Combat pathogens causing tuberculosis (TB) and leprosy.

  • Antituberculosis Drugs:

    • Rifampin

    • Pyrazinamide

    • Ethambutol (Myambutol)

    • Streptomycin

    • Rifapentine (Priftin)

    • Isoniazid (INH).

  • Leprostatic Drugs:

    • Dapsone

    • Thalidomide.

ANTIMYCOBACTERIALS: TREATMENT CONSIDERATIONS

  • Treatment Length: TB requires prolonged therapy (6 months to 2 years) due to slow growth of Mycobacterium tuberculosis.

  • Use of Combination Therapy: Reduces emergence of resistant strains; first-line drugs include isoniazid, rifampin, pyrazinamide, ethambutol, rifabutin, and rifapentine.

  • Second-line drugs may be employed if the first-line is ineffective due to resistance.

ANTIMYCOBACTERIALS: MECHANISM OF ACTION AND INDICATIONS

  • Mechanism: Acts on bacterial DNA, inhibiting growth, leading to bacterial death.

  • Indications: For the treatment of TB and leprosy.

  • Pharmacokinetics: Absorbed well orally, metabolized in the liver, excreted in urine; crosses the placenta and enters breast milk.

ANTIMYCOBACTERIALS: CONTRAINDICATIONS AND ADVERSE EFFECTS

  • Contraindications: Allergy, renal/hepatic failure, CNS dysfunction, pregnancy.

  • Adverse Effects: Can include CNS effects and gastrointestinal irritation; interplay with drugs may cause liver toxicity (particularly with rifampin and INH).

FIRST LINE TB DRUGS

  1. Isoniazid (INH):

    • Common Side Effects: GI upset, rash, fatigue.

    • Adverse Effects:

      • Hepatotoxicity (elevated liver enzymes).

      • Peripheral neuropathy (B6 deficiency, can be prevented with pyridoxine).

      • Rare occurrences of psychosis or seizures.

  2. Rifampin (RIF):

    • Common Side Effects: GI upset, mild flu-like symptoms.

    • Adverse Effects:

      • Hepatotoxicity (hepatitis).

      • Red-orange discoloration of bodily fluids (tears, urine, sweat), harmless but important for patient education.

      • Drug-drug interactions affecting CYP450, potentially reducing efficacy of oral contraceptives, anticoagulants, and antivirals.

  3. Pyrazinamide (PZA):

    • Common Side Effects: GI upset, rash, joint pain.

    • Adverse Effects:

      • Hepatotoxicity.

      • Hyperuricemia, leading to gout attacks.

  4. Ethambutol (EMB):

    • Common Side Effects: GI upset, headache.

    • Adverse Effects:

      • Optic neuritis (blurred vision, red-green color blindness; requires baseline and periodic vision tests).

      • Other rare effects include rash, joint pain.

KEY NURSING CONSIDERATIONS FOR TB

  • Monitor liver function, especially with INH, rifampin, pyrazinamide.

  • Educate about body fluid discoloration with rifampin.

  • Regular vision assessments during ethambutol therapy.

  • Supplement with vitamin B6 for INH use.

  • Importance of long-term adherence to therapy to prevent resistance.

LEPROSTATIC DRUGS

  • Dapsone (generic): Antibiotic treating leprosy, functioning similar to sulfonamides; also indicated for treating Pneumocystis jirovecii and brown spider bites.

  • Thalidomide: Approved to manage cutaneous reactions from leprosy; initially banned due to severe birth defects in the '50s, now restricted to specific indications such as multiple myeloma when combined with dexamethasone (requires negative pregnancy test documentation).

DAPSONE – ADVERSE REACTIONS

  • Hematologic Toxicities:

    • Hemolytic anemia (particularly in G6PD deficiency).

    • Methemoglobinemia (decreased oxygen transport capability; may result in cyanosis or shortness of breath).

    • Agranulocytosis or aplastic anemia (rare but severe).

  • Hypersensitivity Reactions:

    • Dapsone hypersensitivity syndrome presenting with fever, rash, lymphadenopathy, and hepatitis (potentially fatal if unrecognized).

  • Hepatic Concerns:

    • Hepatitis and elevated liver enzymes.

  • Dermatologic Effects:

    • Severe rash including Stevens-Johnson syndrome (very rare but critical).

DAPSONE: NURSING CONSIDERATIONS

  • Monitor complete blood counts regularly for blood dyscrasias.

  • Identify early signs of hemolysis (dark urine, jaundice, fatigue), especially in G6PD-deficient patients.

  • Monitor liver function tests (LFTs).

  • Educate patients to report unusual bruising, bleeding, persistent sore throat, rash, or jaundice promptly.

OTHER ANTIBIOTICS

  • Lincosamides: Clindamycin (Cleocin), Lincomycin (Lincocin); similar to macrolides; bacteriostatic; disrupts protein synthesis in gram-positive bacteria.

  • Lipoglycopeptides: telavancin (Vibativ), dalbavancin (Dalvance), oritavancin (Orbactiv), Vancomycin (Vancocin); used for treating complicated skin infections susceptible to gram-positive bacteria.

  • Macrolides: Erythromycin (Ery-Tab, Eryc, etc.), Azithromycin (Zithromax), Clarithromycin (Biaxin), fidaxomicin (Dificid).

    • Used for treating respiratory infections, skin infections, sinus infections, legionnaires, ureaplasma, and chlamydia infections; appropriate for patients allergic to penicillin.

    • Fidaxomicin is specifically used for Clostridium difficile diarrhea.

  • Oxazolidinones: Tedizolid (Sivextro), linezolid (Zyvox); for treating pneumonia and skin infections, diabetic ulcers.

  • Monobactams: Aztreonam (Axactam); effective against gram-negative enterobacterial infections.

MACROLIDES: COMMON SIDE EFFECTS

  • Milder Effects:

    • GI upset (most common): Includes nausea, vomiting, diarrhea, abdominal cramping.

    • Changes in taste (metallic taste often associated with clarithromycin).

    • Headaches, dizziness, mild rashes.

MACROLIDES: CARDIOLOGICAL AND HEPATIC EFFECTS

  • Cardiac Effects: QT interval prolongation → risk of torsades de pointes and life-threatening arrhythmias.

  • Hepatic Effects: Hepatotoxicity (rare but serious): Includes cholestatic hepatitis, elevated liver enzymes, jaundice.

  • Superinfections: Risk of Clostridioides difficile-associated diarrhea (CDAD).

  • Hypersensitivity Reactions: Rare severe rashes.

RE-CAP SO FAR

  • Classification of medications:

    • Narrow-spectrum: Effective against few pathogens.

    • Broad spectrum: Effective against a wide array of pathogens.

  • Mechanism of action:

    • Bacteriostatic: Prevents replication.

    • Bactericidal: Kills bacteria.

  • Understanding different drug classes: Antibacterial, antifungal, antiviral agents.

WHEN SELECTING AN ANTIBIOTIC

  • Factors to Consider:

    • Identify the causative agent.

    • Sensitivity of the infecting organism.

    • Host factors (location of infection, age, allergies, immune response).

VIRAL INFECTIONS, HIV, AND AIDS

  • Antiviral Medications: Act by altering viral reproduction, only effective during active replication.

COMMON VIRUSES CHARACTERISTICS

  • Viruses: Cannot replicate independently.

    • Must attach to and enter a host cell, utilizing the cell's energy to synthesize necessary biological material.

    • Drugs effective against viruses also risk damaging host cells.

VIRUSES RESPONDING TO ANTIVIRAL THERAPY

  • Influenza A & Other Respiratory Viruses: Oseltamivir (Tamiflu).

  • Herpes Viruses: Acyclovir, valacyclovir, famciclovir.

  • Cytomegalovirus (CMV): Ganciclovir for treatment and prevention.

  • HIV: Various anti-retroviral classes including non-nucleoside reverse transcriptase inhibitors, protease inhibitors.

  • Hepatitis B & C: Interferon alfa-2b, lamivudine for hepatitis C.

INFLUENZA VIRUSES A&B

  • Neuraminidase Inhibitors:

    • Oseltamivir (Tamiflu) – oral.

    • Zanamivir (Relenza) – inhaled.

    • Peramivir (Rapivab) – IV.

    • Mechanism: Inhibit neuraminidase enzyme, resulting in preventing release of new viral particles from infected cells.

    • Adverse Effects: Nausea, vomiting, headache; zanamivir may cause bronchospasm in asthmatic/COPD patients.

RSV (RESPIRATORY SYNCTYAL VIRUS)

  • Ribavirin (inhaled or oral): Broad-spectrum antiviral inhibiting viral RNA synthesis, used in severe RSV infections.

  • Palivizumab (Synagis): Not a treatment but prophylaxis for high-risk infants.

    • Adverse Effects: Rash, injection site reactions.

NURSING CONSIDERATIONS FOR ANTIVIRALS

  • Timing: Antivirals for influenza are most effective started within 48 hours of symptom onset.

  • Monitoring: Observe for GI upset, CNS effects; ensure lung disease screening before zanamivir.

  • Education: Discuss teratogenic risks associated with ribavirin.

AGENTS FOR HERPES AND CYTOMEGALOVIRUS

  • Indications: Inhibit viral DNA replication.

  • Pharmacokinetics: Absorbed in GI tract; metabolized in the liver; chiefly excreted in urine and feces.

  • Contraindications: Known allergies, very toxic in pregnancy/lactation, renal disease.

  • Adverse Effects: GI upset, headache, rash, paresthesias, risk of nephrotoxicity.

FIRST-LINE ANTIVIRAL AGENTS (HSV-1 & HSV-2)

  • Acyclovir: Most common for HSV; needs multiple doses due to short half-life, nephrotoxic risk particularly in IV form.

  • Valacyclovir: Prodrug with better bioavailability; used for HSV and shingles.

  • Famciclovir: Similar use as valacyclovir.

TOPICAL AGENTS FOR HSV

  • Penciclovir cream: For recurrent herpes labialis.

  • Acyclovir cream: Used for HSV lesions but less effective than oral or IV forms.

AGENTS FOR CMV

  1. Ganciclovir (IV, oral): First-line therapy for CMV infections; inhibits viral DNA polymerase.

    • Adverse Effects: Bone marrow suppression, nephrotoxicity, GI upset.

  2. Valganciclovir (oral): Prodrug; also for long-term suppression in immunocompromised patients.

    • Adverse Effects: Similar to ganciclovir, including hepatotoxicity.

  3. Foscarnet (IV): Ganciclovir-resistant CMV infections.

    • Adverse Effects: Nephrotoxicity, electrolyte imbalances.

  4. Cidofovir (IV): Alternative for resistant CMV; requires hydration.

CMV MEDS - NURSING CONSIDERATIONS

  • Monitor CBC for bone marrow suppression; renal function and electrolytes with foscarnet/cidofovir therapies.

  • Educate on adherence to therapy and importance in preventing relapse.

FUNGUS IS DIFFERENT FROM BACTERIA

  • Composed of rigid cell walls made of chitin; fungi have protective structures making them resistant to antibiotics.

PATIENTS SUSCEPTIBLE TO FUNGAL INFECTIONS

  • Include individuals with:

    • AIDS

    • Organ transplants

    • Chemotherapy recipients

    • Elderly individuals formerly protected from environmental fungi.

AZOLE ANTIFUNGALS

  • Used for systemic and topical fungal infections.

  • Mechanism: Binds to sterols causing cell death; inhibits glucan synthesis.

  • Pharmacokinetics: Rapid absorption from the GI tract, metabolized in the liver, excreted in urine.

AZOLE ANTIFUNGALS: CONTRAINDICATIONS AND SIDE EFFECTS

  • Contraindications: Hepatic/renal dysfunction, pregnancy/lactation, medications that prolong QTc interval.

  • Common Side Effects: GI upset, headache, rash.

  • Serious Effects: Hepatotoxicity, liver function monitoring necessary during longer treatments.

ECHINOCANDIN ANTIFUNGALS

  • Examples: Caspofungin, micafungin, anidulafungin.

  • Function by inhibiting β-(1,3)-D-glucan synthesis, crucial for fungal cell wall integrity.

  • Indications: Treats invasive candidiasis, Aspergillus infections; commonly used in critically ill/immunocompromised individuals.

OTHER ANTIFUNGAL AGENTS

  1. Griseofulvin: For dermatophyte infections; inhibits fungal cell division via disruptive spindle mechanism. Monitor for hepatotoxicity.

  2. Terbinafine (Lamisil): Targets dermatophyte infections; inhibits squalene epoxidase, preventing ergosterol synthesis.

  3. Flucytosine: Used alongside amphotericin B for serious systemic infections, particularly cryptococcal meningitis; can cause bone marrow suppression.

  4. Tolnaftate (Tinactin): OTC for mild tinea infections; rare local irritation.

NURSING CONSIDERATIONS FOR SYSTEMIC ANTIFUNGAL AGENTS

  • Assess for physical status and allergies to antifungal agents; monitor renal, hepatic function tests, and CBC.

TOPICAL ANTIFUNGALS

  • Indicated for local treatment of mycoses (including various tinea infections).

  • Pharmacokinetics: Non-systemic absorption; contraindicated only if known allergy present.

  • Adverse Effects: Local irritation, burning, rash.

COMMON TOPICAL ANTIFUNGAL AGENTS

  • Clotrimazole, miconazole, ketoconazole, terbinafine, tolnaftate, nystatin, ciclopirox.

ANTI-INFLAMMATORY AND ANTI-ARTHRITIS AGENTS

  • Definition: Used to manage tissue injury caused by physical or chemical agents or pathogenic microorganisms.

  • Inflammatory process includes:

    • Capillary widening.

    • Increased permeability.

    • Attraction and extravasation of leukocytes.

    • Systemic response with heat, redness, swelling, tenderness, and pain.

ANTI-INFLAMMATORY AGENTS - OVERVIEW

  • Various drug types:

    • Corticosteroids: Block/alter chemical reactions linked with inflammation.

    • Antihistamines: Block histamine release during inflammatory response.

    • Immune-modulating agents.

    • OTC anti-inflammatories.

  • All anti-inflammatory medications carry potential adverse effects.

SALICYLATES

  • Examples:

    • Aspirin (acetylsalicylic acid): Most widely used.

    • Methyl salicylate (topical).

    • Salsalate (oral), less GI irritation than aspirin.

  • Mechanism of Action: Inhibits COX-1 and COX-2 enzymes, reducing prostaglandin synthesis; offers analgesic, antipyretic, anti-inflammatory effects (Aspirin additionally has antiplatelet effects).

SALICYLATES: THERAPEUTIC USES

  • Effective for:

    • Mild to moderate pain.

    • Fever reduction.

    • Anti-inflammatory indications (e.g., arthritis, rheumatic conditions).

    • Antiplatelet purpose to prevent MI, stroke, TIA.

SALICYLATES: COMMON SIDE AND SERIOUS ADVERSE EFFECTS

  • Common Side Effects: GI upset, heartburn, mild bleeding.

  • Serious Adverse Effects:

    • GI bleeding.

    • Salicylism (toxicity symptoms include tinnitus, confusion).

    • Reye’s syndrome risk in children with viral illnesses (prohibit use with flu or varicella).

NURSING CONSIDERATIONS FOR SALICYLATES

  • Administer with food/milk to minimize GI irritation.

  • Monitor for signs of GI bleeding; avoid in children/adolescents with viral illness.

  • Monitor for early signs of salicylism toxicity (tinnitus).

NONSTEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDs)

  • Definition: Some of the strongest medications for anti-inflammatory and analgesic effects, available OTC (leading to potential misuse).

  • Mechanism of Action: Block COX-1 and COX-2 enzymes.

  • Pharmacokinetics: Rapidly absorbed from GI; peak in 1 to 3 hours; metabolized in the liver; primarily excreted in urine.

NSAIDs: CONTRAINDICATIONS AND CAUTIONS

  • Contraindications: Allergy to NSAIDs or salicylates; heightened caution for celecoxib in patients allergic to sulfonamides, with cardiovascular conditions, peptic ulcer disease, or renal/hepatic dysfunction.

ACETAMINOPHEN

  • Actions: Reduces fever and manages pain through effects on the thermoregulatory cells of the hypothalamus and is associated with various conditions (e.g., flu, arthritis).

  • Pharmacokinetics: Absorbed in the GI tract; half-life of 0.5-2 hours; metabolized in the liver; excreted through urine.

  • Contraindications: Known allergy, cautious use in pregnancy/lactation, hepatic dysfunction/ chronic alcoholism.

ACETAMINOPHEN: ADVERSE EFFECTS

  • Common: headache, skin rash, hemolytic anemia.

  • Serious: hepatotoxicity (with chronic use or overdose).

  • Drug-Drug Interactions: Increases bleeding potential with oral anticoagulants.

ANTIARTHRITIS AGENTS

  • Definition: Used to prevent and suppress inflammatory processes in rheumatoid arthritis patients.

  • Common Treatments:

    • NSAIDs: Often require high doses.

    • DMARDs (Disease-Modifying Anti-Rheumatic Drugs): Usually the first-line treatment.

    • Biologics: Offer targeted therapy for severe RA.

    • Steroids: Useful for acute flares; suitable for short-term usage.

COMMON DMARDS USED IN ARTHRITIS/TREATMENT

  • Methotrexate: Most commonly used; weekly dosing; monitor for hepatotoxicity, pulmonary toxicity, and oral ulcers.

  • Hydroxychloroquine: Used for Rheumatoid Arthritis and Lupus; monitor for retinal damage.

  • Sulfasalazine: Monitor for GI upset, rash, hepatotoxicity.

  • Leflunomide: Monitor closely for hepatotoxicity and teratogenic effects.

BIOLOGIC DMARDs (BDMARDS) - FOR MODERATE TO SEVERE DISEASE

  • Tumor Necrosis Factor (TNF-α) Inhibitors: (Examples include etanercept, infliximab, adalimumab); important to screen for TB and hepatitis prior to therapy.

  • Other Biologics: Include anakinra (IL-1 inhibitor), tocilizumab (IL-6 inhibitor), abatacept (T-cell modulator), rituximab (B-cell depletor).

TARGETED SYNTHETIC DMARDS (TSDMARDS)

  • JAK Inhibitors: Oral agents like tofacitinib and baricitinib.

  • Adverse Effects: Risk of infections, cytopenias, elevation in liver enzymes, thrombosis.

DMARDS: NURSING CONSIDERATIONS

  • DMARDs take weeks to months for full effects; not for immediate relief.

  • Teach patients the infection risk and the importance of reporting adverse signs like fever or unhealed wounds; avoid live vaccines during treatment.

  • Education on medications with teratogenic risks (like methotrexate, leflunomide).