Chapter 9 – antibiotics Antibiotics - Chemicals that inhibit specific bacteria Types of antibiotics - Bacteriostatic o Substance that prevents the growth of bacteria - Bactericidal o Substance that kills the bacteria directly Signs of infection - Fever - Lethargy - Slow-wave sleep induction - Classic signs of inflammation (redness, swelling, heat, and pain) Goal of Antibiotic therapy - Decrease the population of invading bacteria to a point where the human immune system can effectively deal with the invaders Selecting treatment - Identification of the causative organism - Based on the culture report, an antibiotic is chosen that is known to be effective at treating the invading organism Bacteria classification - Gram-positive o The cell wall retains a stain or resists decolorization - Gram-negative o The cell wall loses a stain or is decolorized by alcohol - Aerobic o Depend on oxygen for survival - Anaerobic o Do not use oxygen Aminoglycosides (-mycin/micin) - A group of powerful antibiotics used to treat serious infections caused by gram-negative aerobic bacilli - Common medications; o Amikacin (amikin) o Gentamicin (garamycin) o Kenamycin (kantrex) o Neomycin (mycifradin) o Streptomycin o Tobramycin (Nebcin, tobrex) - Bactericidal - Indication: treatment of serious infection caused by susceptible bacteria - Action: inhibits protein synthesis in susceptible strains of gram-negative bacteria causing cell death - - - - Pharmacokinetics: o Poorly absorbed from the GI tract but rapidly absorbed after IM injection, reaching peak levels within 1 hour o Widely distributed throughout the body, crossing the placenta and entering breastmilk o Excreted unchanged in the urine and have an average half-life of 2 to 3 hours o Depend on the kidney for excretion and are toxic to the kidney Contraindication o Known allergies, renal or hepatic disease, and hearing loss Adverse effects o Ototoxicity and nephrotoxicity are the most significant Drug-to-drug interaction o Diuretics and neuromuscular blockers Combined w/ potent diuretics – incidence of ototoxicity, nephrotoxicity and neurotoxicity increases Combined w/ anesthetics – nondepolarizing neuromuscular blockers, succinylcholine, or citrate anticoagulated blood, increased neuromuscular blockage w/ paralysis is possible - - - - - Cephalosporins (Cef/ceph-) Similar to penicillin in structure and activity Action o Interfere with cell-wallbuilding ability of bacteria when they divide Indication o Treatment of infection caused by susceptible bacteria Pharmacokinetics o Well absorbed in the GI tract o Metabolized in the liver, excreted in the urine Contraindication o Allergies to cephalosporins and penicillin Adverse effects o GI tract Drug-to-drug interactions o Aminoglycosides, oral anti-coagulants, and ETOH Fluoroquinolones (-floxacin) - Relatively new class of antibiotics with a broad spectrum of activity - Indications o treat infection caused by susceptible strains of gram-negative bacteria, including urinary tract, respiratory tract and skin infections - Actions o interfere with DNA replication in susceptible gramnegative bacteria, preventing cell reproduction - Pharmacokinetics o Absorbed in the GI tract o Metabolized In the liver o Excreted in the urine and feces - Contraindications o Known allergy, pregnancy and lactation - Adverse effect o Headache, dizziness, and GI upset - Drug-to-drug interactions o Antacids, quinidine, and theophylline Macrolides (thromycin) - Antibiotics that interfere with protein synthesis in susceptible bacteria - - - - Indications o Treatment of respiratory, dermatologic, urinary tract, and GI infections caused by susceptible strains of bacteria Actions o Binds to cell membrane causing a change in protein function and cell death; can be bacteriostatic or bactericidal Pharmacokinetics o Absorbed from the GI tract o Metabolized in the liver, excreted in the bile to feces Contraindications o Allergy and hepatic dysfunction Adverse effects o GI symptoms Drug-to-drug interactions o Digoxin, oral anticoagulants, theophylline, and corticosteroids Lincosamides (li-mycin) - Similar to macrolides but more toxic - Action o Similar to macrolides - Indications o Severe infections o - - - Pharmacokinetics o Well absorbed from the GI tract or IM o Metabolized in the liver and excreted in the urine and feces Contraindications o Hepatic or renal impairment Adverse effects o GI reactions Monobactams (nam) - Unique structures with little cross-resistance - Actions o Disrupts bacteria cell wall synthesis, which promotes the leakage of cellular content and cell death - Indications o Treatment of infections caused by susceptible bacteria: UTI, skin, intraabdominal, and gynecologic infections - Contraindication o Allergy - Adverse effects o GI and hepatic enzyme elevation Penicillin (cillin) - The first antibiotics introduced in the clinical use - Actions - - - - Inhibits the synthesis of the cell wall in the susceptible bacteria, causing cell death Indications o Treatments of infections caused by streptococcal pneumococcal, staphylococcal, and other susceptible bacteria Pharmacokinetics o Well absorbed from the GI tract o Excreted unchanged in the urine Contraindications o Allergy o Caution in patients with renal disease Adverse effects o GI effects Drug-to-drug interactions o Tetracyclines and aminoglycosides Sulfonamides (sulfa-) - Drugs that inhibit folic acid synthesis - Action o Interfere with the cellwall-building ability of dividing bacteria - Indications o Treatment of infections caused by gramnegative and gram positive-bacteria - - - Pharmacokinetics o Well absorbed from the GI tract o Metabolized in the liver and excreted in the urine Contraindication o Allergy and pregnancy Adverse effects o GI symptoms and renal effects related to the filtration of the drug Drug-to-drug interactions o Cross sensitivity with thiazide diuretics o Sulfonylureas Tetracyclines (cycline) - Developed as semisynthetic antibiotics based on the structures of a common soil mold - Actions o Inhibits protein synthesis in susceptible bacteria, preventing cell replication - Indications o Treatment of various infection caused by susceptible strains of bacteria and acne, and when penicillin is contraindicated for eradication of susceptible organisms - - - Pharmacokinetics o Adequately absorbed from the GI tract o Concentrated In the liver and excreted unchanged in the urine Contraindications o GI, skeletal: damage to bones and teeth Drug-to-drug interaction o Penicillin G, oral contraceptives therapy, methoxyflurane, and digoxin Antimycobacterial - Contain pathogen causing tuberculosis and leprosy - Action o Act on the DNA of the bacteria, leading to lack of growth and eventually bacterial death - Indication o Treatment of acid-fast bacteria - Pharmacokinetics o Well absorbed from the GI tract o Metabolized in the liver and excreted in the urine - Contraindications o Allergy and renal or hepatic failure - Adverse effects o CNS effect and GI irritation - Drug-to-drug interactions o Rifampin and INH can cause liver toxicity Antibiotic used across the lifespan - Pediatric population - Adult population - Geriatric population Nursing considerations – aminoglycosides, cephalosporin, fluroquinolones, macrolides and lincosamides, monobactams, penicillin, sulfonamides, tetracycline, antimycobacterial - Assessment and history Nursing diagnosis Implementation Evaluation SIDE NOTES: Antibiotic medication – 7 days Strong anti biotics = side effects Sulfonylureas – oral antidiabetic Do not take pills with antibiotics Pag nawalan ka ng chicken pox tapos bumalik ulit that means you acquired shingles (herpes zoster) T – Toxoplasmosis – cat’s litter O - other (such as syphilis, varicella, mumps, parvovirus, and HIV) R – Rubella C - cytomegalovirus H – herpes simplex ANTIMYCOBACTERIAL drugs Category 1 R - Rifampin I - Isoniazide P - Pyrazinamide E - Ethambutol S - Streptomycin Category 2 Nagamot na dati or dae narahay or bumalik – relapse Specific drug to specific invaders thru culture Identified by its “genetic coat” by immune system Thromycin – macrolides sinasabay sa covid q24hrs Pag premature ang baby pinapainom ng beta-metasol to mature the lung surfactant that makes dilation of alveoli Steroid – anti-inflammatory Kaposii sarcoma Pneumocystis carinii – AIDS HPV – acquired cancer (cervical cancer)
