- Drugs of choice for very serious/virulent infections
- not given orally due to poor absorptions, the exception is Neomycin)
- Most commonly used for the treatment of systemic infections
- Amikacin (Amikin)
- Gentamicin (Garamycin)
- Tobramycin (Tobrex)
** Serum drug levels are essential to patient safety and medication effectiveness. (dosage is adjusted accordingly).
- Specifically monitoring for: Nephrotoxicity (toxicity of the kidneys), rising creatinine suggests decreased kidney function. Ototoxicity (temporary or permanent hearing loss.
- Peak level for once a day doses are usually not drawn (5-10mcg/ml)
- Trough (lowest) levels are measured to assess for renal clearance and to avoid toxicity.
- drawn at least 12 hours after completion of the dose.
- Approximately 18 hours after for those with renal impairment.
- ** Therapeutic goals is a trough of concentration at or below 1 mcg/mL.
- Normally monitored initially once every 5-7 days until antibiotic completed.
Aminoglycosides - Mechanism of action
- Bind to ribosomes and prevent protein synthesis in bacteria.(causes cell death)
- Often used in combo with beta-lactams or vancomycin (synergistic effect)
- - in this case, give the beta-lactams first.
Aminoglycosides - Indications
- Used for serious gram negative infections and specific gram positive (usually use a penicillin)
- Gram negative usually treated with an amino glycoside and extended spectrum penicillin, third generation cephalosporin, or carbapenems are: Pseudomonas species, escherichia coli, proteus species, klebsiella specie, serrate species.
- Gram Positive usually treated with aminglycosides are: Enterococcus, staph aureus.
- Prophylaxis for invasive procedures involving GI tract (Gut surgery)
- combined with ampicillin in those with valvular heart disease (prone to enterococcal infections)
- Streptomycin active against mycobacterium species.
Aminoglycosides - Contraindications
- Drug allergy
- will cross the placenta causing irreversible bilateral hearing loss.
- crosses into breast milk, pregnant/lactating
- renal failure, hepatic disease, pre-existing hearing loss(makes it worse), myasthenia gravis (symptoms worsen), Parkinson's.
Aminoglycosides - Adverse reactions
- Nephrotoxicity occurs in about 5-25% of patients (may progress to renal failure)
- Nephrotoxicity is manifested by urinary casts, protein urea, increased BUN, and creatinine. Nephrotoxicity is usually reversible.
- Ototoxicity occurs in 3-14% and is usually not reversible. believed to result from injury to the 8th cranial nerve (cochleovestibular nerve), causes damage to the hearing and balance (vestibular). Manifested by dizziness, tinnitus, feeling of fullness in the ears, hearing loss. Other symptoms are headache, parasthesias, vertigo, skin rash, fever, neuromuscular paralysis.
- Hematological - bone marrow depression due to direct drug effect may lead to immune suppression and superinfection.
- GI system - N/V/D, weight loss, stomatitis, and hepatic toxicity.
- Skin Effects - photosensitivity, purport, rash, uticaria, exfoliative dermatitis.
- Cardiac - palpations, hypotension, hypertension.
- risk for toxicity is creates with high doses or prolonged therapy.
Aminoglycoside - Interactions
-Nephrotoxicity increase with use to vancomycin, cyclosporine, and amphotericin B.
- Use with loop diuretics increases risk for ototoxicity.
- Reduce the amount of vitamin k in the gut --> may cause warfarin toxicity
- Anesthetics/neuromuscular blockers - increase neuromuscular blockage and paralysis may be possible.
Aminoglycoside - Nursing implications
- C&S report
- Monitor serum drug levels (peak and trough) to prevent ototoxicity and nephrotoxicity.
- Monitor regularly for s/s of nephro/neuro/ototoxicity, and bone marrow depression.
- Provide safety measures to protect patient should neuro toxicity occur.
- Small frequent meals, good mouth care, ice chips, sugarless hard candy.
- proper hydration to aide in the avoidance of renal toxicity.
- Teach safety precautions (slow change of position), avoiding driving until response is established, drink liberal amounts of fluid, avoid exposure to other infections and report any side effects.
Aminoglycosides - individual drugs
- Amikacin (Amikin)
- Gentamycin (Garamycin)
- Neomycin (Neo-fradin)
- primarily for gram negative infections, severe staphylococcal infections.
IV/IM 2-6mg/kg/day divided 1-4 times daily or 5-7 mg/kg once daily.
Quinolones (fluoroquinolones) - mechanism of actions and effects
- Destroy bacteria by altering DNA (cause cell death, because they cannot replicate)
- believed to concentrate themselves in neutrophils, and kill the bacteria.
- drug resistance exists with this classification.
Quinolones (Fluoroquinolones) - Indications
- Active against a wide variety of gram negative and gram positive.
- treatment of infections caused by susceptible strains of gram negative bacteria and some gram positive, i.e. E. coli, pseudomonas, strep, and staph.
- respiratory infections (lower respiratory)
- skin infections
- urinary tract infections
- eye infections
- ear infections
- bone and joint infections
- treat after anthrax exposure
Quinolones (Flouroquinolones) - Indications
- Stockpiled after 9/11 to treat potential anthrax. (prophylaxis)
- not recommended for use in prepubescent children-->may cause adverse effects on cartilage development.
Quinolones (Fluoroquinolones) - Adverse effects
- Dizziness, insomnia, H/A, dry mouth, N/V/D, rash, fever, bone marrow depression, skin reaction, photosensitivity
** Prolongation of the QT interval--> cardiac dysrhythmia when take with class la and class III (can be fatal)
- Antidysrhythmic drugs: especially disopyramide (Norpace) and amiodarone (Cordarone)
- ** Increased risk for tendonitis and tendon rupture; most commonly seen in the elderly with renal dysfunction and those taking glucocorticoids (Prednisone)
Quinolones (Fluoroqinolones) - Interactions
- Antacids, iron, zinc will decrease effectiveness.
- give calcium and magnesium 1 hour before or after taking quinolones.
- Oral contraceptives are to be used with caution due to alteration of Vitamin K, may cause blood clots (ex. woman who smoke along with taking oral contraceptives can lead to blood clots).
- Quinolones (Fluoroquinolones)
- IV 200-400mg q 12 hours
- PO 250-750 mg q 8-12 hours
- Can be bacteriostatic or bactericidal (concentration dependent)
- Used in treating chronic bone infections, GU infections, Intraabdominal infections, serious skin infections, anaerobe pneumonia, septicemia.
- Most Gram Positive bacteria are susceptible.
- active against several anaerobic organisms.
- Contraindications - known allergy, ulcerative colitis, infants < 1 month of age
- Adverse effects - N/V/D, abdominal pain, pseudomembranous colitis.
-- may enhance actions of neuromuscular blocking agents, i.e. vecuronium (Norcuron) (will paralyze people), monitor for paralysis and respiratory status.
- Dosage - IV/PO 300-900 mg BID or QID
- Inhibits bacterial protein synthesis
- originally developed to treat vancomycin-resistant Enterococcus Faecium (VRE)
- Used to treat hospital acquired pneumonia, complicated skin infection caused by MRSA
- Adverse effects - H/A, N/V/D, may decrease platelet count
-*** Great absorption via the oral rout (given in pill form or suspension)
- Interactions - may strengthen effects of vasopressors; i.e. dopamine, may cause serotonin syndrome, tyramine-contining foods.
Dose - IV/PO 400-600mg q 12 hours.
- Avoid aged and heavily processed foods.
- An antimicrobial that interferes with DNA synthesis
- Effective against anaerobic organisms
- used to treat intraabdominal and gynecological infections, also used to treat protozoal infections
- Adverse Reactions - Dizziness, headache, GI discomfort, Nasal congestion, reversible neurtopenia and thrombocytopenia.
- Interactions - Alcohol will cause acute alcohol intolerance due to accumulation of acetaldehyde. Avoid alcohol for 24 hours before starting Flagyl.
- increase toxicity of lithium benzodiazapenes, cyclosporine, calcium channel blockers, warfarin, various antidepressants (vanlafaxine)
- Phenytoin and phenobarbital may decrease effects of metronidazole (Flagyl)
- Dose - IV/PO 250-500mg q 6-12 hours
- Bactericidal that binds to cell wall causing inhibition of cell wall synthesis and death
- not active against gram negative bacteria, fungi, or yeast.
- Indications - C.diff, staph. enterocolitis, staph infections of bone and joint, sepsis.
- contraindications - preexisting renal dysfunction, hearing loss, the elderly, and neonates.
- Adverse effects - blood levels above 50mcg/mL may result in toxic effect. Ototoxicity, Nephrotoxicity, Red man syndrome.
Urinary Agents- Nitrofurantoin (Macrodantin, Macrobid)
- acts agains E. coli
- short term use or long term used to suppress bacteria in recurrent UTI's
- Prevention of UTI's caused by gram negative and gram positive organisms including e.coli, s. aureus, enterococcus, klebsiella, enterbacter or long term suppression of UTI, bacteria in recurrent UTI's.
- bacterial resistance develops slowly and to a limited degree.
- Adverse effects - rash, anorexia, N/V, dark urine, abdominal pain, diarrhea.
- Contraindications - severe Renal Disease, allergy.
Urinary Agents - Phenazopyridine (Pyridium)
- an azo dye that acts as a urinary analgesic to relieve symptoms of burning, frequency, and urgency
- Has no anti-infective properties
- Turn the urine orange-red (Benign issue) - inform the patient of this.
- Contraindicated in renal insufficiency and sever hepatitis (people with hepatitis also have dark urine, so we do not know if Hepatitis is exacerbating or not).
- Dosage - 100-200 mg 3-4 times a day.
- Side effects - Headache, GI disturbances, rash
- Treat the symptoms, does not have antibiotic effect.