NURS 133 Cephalosporins and Aminoglycosides

jasmine's version from 2016-04-18 06:26

Section 1

Question Answer
Cephalosporins Most widely used; Bactericidal beta-lactam (beta-lactam ring) antibiotics. They inhibit enzymes in the cell wall of susceptible bacteria, disrupting cell synthesis. They cover a broad range of organisms, are generally well-tolerated, and are easy to administer; thus, these agents are frequently used. There are 5 generations of cephalosporins. The first generation drugs are effective mainly against gram-positive organisms. Higher generations have expanded spectra against aerobic gram-negative bacilli. The fifth generation cephalosporin ceftaroline is active against methicillin-resistant S. aureus (MRSA) and E. faecalis. Cephalosporins have the following limitations: Lack of activity against enterococci (except for ceftaroline), methicillin-resistant staphylococci (except for ceftaroline), and anaerobic gram-negative bacilli (except for cefotetan and ceftaroline);
Cephalosporin actions Exert bactericidal effect; targets bacterial cell wall, making it defective and unstable. Cephalosporins penetrate well into most body fluids and the ECF of most tissues, especially when inflammation (which enhances diffusion) is present; All cephalosporins penetrate poorly into ICF and the vitreous humor
Cephalosporin therapeutic uses Used to treat infections caused by bacteria: respiratory, ear, bone/joint, genitourinary tract infections, and also used throughout peri-operative period; Used in urinary tract infections; skin infections; hospital-acquired pneumonias
Elimination/Excretion of Cephalosporins Excreted primarily in urine, so doses must be adjusted in patients with renal insufficiency; cefoperazone and ceftriaxone, which have significant biliary excretion, do not require dose adjustment
Adverse/Side Effects of Cephalosporins Hypersensitivity; nephrotoxicity, aplastic anemia, toxic epidermal necrolysis; GI reactions: nausea, vomiting, diarrhea; Headache, dizziness, malaise, heartburn, fever. Approximately 10 percent of people allergic to penicillin are also allergic to cephalosporins
Contraindications of Cephalosporins In patients allergic to cephalosporins or penicillins; Use cautiously in patients with renal disease, hepatic impairment, bleeding disorder, pregnancy, known penicillin allergy; Cephalosporins enter breast milk and may alter bowel flora of the infant; thus, use during breast feeding is discouraged
Drug/Food interactions of Cephalosporins Increase risk for nephrotoxicity with aminoglycosides; Increase risk for bleeding with anticoagulants; Disulfiram-like reaction if alcohol consumed within 72 hours (nausea, vomiting); Symptoms may include flushing, throbbing, respiratory problems, vomiting, sweating, chest pain, hypotension. Severe reactions may include arrhythmias and unconsciousness;
Medication administration of Cephalosporins PO, IM, IV
Nursing interventions of Cephalosporins Assess signs and symptoms of infection; Assess for allergies; Obtain general health history before first dose; culture and sensitivity tests; evaluate response to therapy; if infection worsens, notify health care professional; Assess skin for redness, rash, or lesions and if apparent report to health care professional; IM: assess muscle atrophy (gerontologic alert) in non-ambulatory patient or if paralysis is present; IV: assess IV site for phlebitis or thrombophlebitis; PO: if patient experiences GI upset, administer with food or milk; Measure and record fluid intake and output; Monitor blood creatinine levels, especially with renal impairment. Monitor patient’s stools and report any presence of blood and mucus immediately to health care professional; monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly. Assess vaginal itching, drainage; sores in mouth; blood, pus, or mucus in stool or urine; easy bleeding or bruising; rash; unusual fever or chills; respiratory difficulty
Client education of Cephalosporins Instruct patient to take drug as directed, and to complete therapy; Advise to avoid alcohol and take with food or milk if GI upset; Instruct patient to immediately report severe diarrhea and adverse reactions such as blood dycrasia (abnormal or disordered state of the body or of a bodily part) or superinfection to health care professional; IM: Inform patient injection may be painful (sting, burn), and advise patient to report watery, bloody stools even a month after therapy; Emphasize follow up exam
Evaluation/Desired outcomes of Cephalosporins Resolution of infection; Therapeutic effect achieved
Potential nursing diagnoses of Cephalosporins Risk for impaired skin integrity; Risk for impaired comfort; Impaired urinary elimination; Diarrhea

Section 2

Question Answer
Aminoglycosides A group of bactericidal antibiotics, which act by inhibiting bacterial protein synthesis. Their use is restricted because of potential side effects, as they can cause ear and kidney damage. All aminoglycosides resemble each other in antibacterial activity, pharmacokinetics and toxicity. They are not well absorbed when given orally, so need to be given intravenously for systemic infections. They are used when other less toxic antibiotics are contraindicated or ineffective. They are mainly active against gram-negative bacilli, staphylococci and Mycobacterium tuberculosis, but lack activity against anaerobes.
Aminoglycoside actions Disrupt bacterial protein synthesis. Bind to the 30S ribsomal subunit, and thereby cause 1) inhibition of protein synthesis, 2) premature termination of protein synthesis, and 3) production of abnormal proteins (secondary to misreading of the genetic code). Cell kill is concentration dependent. The higher the concentration, the more rapidly the infection will clear. Bactericidal activity persists for several hours after serum levels have dropped below the minimal bactericidal concentration, a phenomenon known as the post-antibiotic effect. Accordingly, bacterial kill appears to result from production of abnormal proteins rather than from simple inhibition of protein synthesis. Studies suggest that abnormal proteins become inserted in the bacterial cell membrane, causing it to leak. The resultant loss of cell contents causes death. Inhibition of protein synthesis per se does not seem the likely cause of bacterial death due to complete blockade of protein synthesis by other antibiotics (e.g., tetracyclines, chloramphenicol) is usually bacteriostatic-not bactericidal.
Aminoglycoside therapeutic uses Treatment of serious infections due to aerobic gram-negative bacilli. Primary target organisms are P. aeruginosa and the Enterobacteriaceae (e.g., E. coli, Klebsiella, Serratia, P. mirabilis). One aminoglycoside, gentamicin-is now commonly used in combination with either vancomycin or a beta-lactam antibiotic to treat serious infections with certain gram-positive cocci, specifically Enterococcus species, some streptococci, and S. aureus. Useful in suppressing GI bacteria-may be used before surgery to reduce the possibility of abdominal infection that may occur after surgery on the bowel.
Elimination/Excretion of Aminoglycosides Eliminated primarily by the kidney. These drugs are not metabolized.
Adverse/Side Effects of Aminoglycosides Can produce serious toxicity, especially to the inner ear and kidney due to concentration within cells of these structures. Nephrotoxicity (damage to the kidneys); Ototoxicity (damage to the hearing organs); Neurotoxicity (damage to the nervous system). Vertigo, myocarditis, hemolytic, anemia, thrombocytopenia, pancytopenia, leukemia, hepatic necrosis, muscle paralysis, anaphylaxis, serum sickness. Nausea, vomiting, rash, urticaria (a rash of round, red welts on the skin that itch intensely, sometimes with dangerous swelling, caused by an allergic reaction, typically to specific foods), superinfection, photosensitivity
Contraindications of Aminoglycosides Hypersensitivity; pre-existing hearing loss, myasthenia gravis and parkinsonism; During lactation, or pregnancy category C, except for neomycin, amikacin, gentamicin, kanamycin, netilmicin, and tobramycin, which are in pregnancy category D. Long term therapy due to the potency for ototoxicity and nephrotoxicity
Drug/Food interactions of Aminoglycosides Risk of injury to the inner ear significantly increased by concurrent use of ethacrynic acid, a loop diuretic that has ototoxic actions of its own. Combining aminoglycosides with other loop diuretics such as furosemide and bumetanide appears to cause no more ototoxicity than aminoglycosides alone. Risk of renal damage is increased by concurrent therapy with other nephrotoxic agents. Additive or potentiative nephrotoxicity can occur with amphotericin B, cephalosporins, polymyxins, vancomycin, and cyclosporine, as well as with aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs). Can intensify neuromuscular blockade induced by pancuronium and other skeletal muscle relaxants. If used with these agents, caution must be exercised to avoid respiratory arrest. Used cautiously in elderly patients, and patients with renal failure and muscular disorders
Medication administration of Aminoglycosides IV and IM, Parental route; may be administered as a single large does each day, or as two or three smaller doses, pending on patient and medical condition. IV infusion should be over 30 minutes or more, and do not mix aminoglycosides and penicillins in same IV solution
Nursing interventions of Aminoglycosides Assess for infection at starting and throughout therapy; vertigo should be assessed before, during and after treatment; Culture and sensitivity analysis; Identify high risk patients (e.g., renal impairment, pre-existing hearing impairment, myasthenia gravis, and patients receiving ototoxic drugs, nephrotoxic drugs, and neuromuscular blocking agents); Monitor intake and output; Monitor serum drug levels (depends on patient and dosing schedule); Assess and monitor for ototoxicity; Assess and monitor for renal function (e.g., BUN and creatinine) and hydration status; Daily weight should be taken; Assess patient for signs of superinfection
Client education of Aminoglycosides Instruct patient to report if there is loss of hearing, feeling of fullness in head, to report headache, dizziness, renal impairment.
Evaluation/Desired outcomes of Aminoglycosides Therapeutic response if there is absence of fever, draining wounds, etc.