Aminoglycosides
General dosing guidelines
|
Overview
| Aminoglycosides: not absorbed orally; IV route primary route of administration-occasionally given IM; quite hydrophilic-distributes primarily in extracellular fluid~25% of body weight; relatively poor tissue penetration; protein binding (20-30%)-not clinically significant; well distributed except for the eye, CNS, CSF. Must be given intrathecally for CNS infections. Increased Vd seen in CHF, peritonitis, ascites, acute burn injury, s/p surgery, immediately post partum patients. Exhibits concentration dependent bactericidal activity. MIC: (Tobra/Gent): Mechanism of Action: Aminoglycosides are rapidly bactericidal. They irreversibly bind to the 30 s bacterial ribosome; protein synthesis is thereby inhibited and cell death ensues. Uptake into bacterial cells is facilitated by cell wall inhibitors (Vancomycin and beta-lactams). |
Initial and follow-up evaluation
| Is the drug appropriate? Is the dose appropriate? Specific patient parameters Follow-up Evaluation Treatment failure: Is the patient responding to treatment? Is the current regimen appropriate? Overview of adverse effects: Monitoring for toxicity: 2. Serum creatinine and BUN determinations 2-3 times/week should monitor 3. Risk factors for Nephrotoxicity: Age, renal insufficiency, elevated trough 4. Toxicity usually takes 5-7 days to develop. Mechanism: damage occurs 5. The process of nephrotoxicity (uptake by cells) is saturable and the |
Serum level monitoring
| Indications for serum concentration monitoring: (1) Patients with compromised renal function (CrCl <50 ml/min) and/or unstable renal function (an increase or decrease in serum creatinine > 0.3 mg/dl). (2) Projected courses of therapy of > 7 days. (3) Suspected treatment failures. Patients not requiring levels include those in whom the assessed dosage regimen is adequate and (1) CrCl >50 ml/min and stable (< 0.3 mg/dl changes in serum creatinine) and Frequency of serum level determinations: Draw levels off the third dose for: Draw levels off the first dose for: |
Once daily dosing protocol
| (Exclusions: Check all that apply: If there are any checks do not use once-daily dosing-use conventional dosing. (1) Patient has febrile neutropenia (2) Burn patient (3) Spinal cord injury (4) R/O meningitis or endocarditis (5) CrCl < 40 ml/min (6) Age < 18 or >70 (7) History of ototoxicity (8) Pregnant (9) Being used for synergy for staph or strept infection. Calculation of Dosing weight Calculate Ideal body weight=_______________kg Calculate Adjusted body weight (ABW) for obese patients. Dosing: (Gent / Tobra) * Moderate infection: 5 mg/kg of dosing weight (wound infection, Pyelonephritis, intraabdominal or pelvic infections, osteomyelitis, etc.) * Severe infection: 6 mg/kg of dosing weight. (Gram negative * Life-threatening: 7 mg/kg of dosing weight. Goals of therapy: Desired trough for once daily dosing: Peak concentrations: (Once daily dosing) Monitoring: |
Amikacin (amikin®)
| Dosing (Adults): Conventional dosing (Usual Dose): I.M., I.V.: 5 to 7.5 mg/kg/dose (based on IBW or use adjusted body weight if current weight is greater than 25-30% over IBW) every 8 hours. Note: dose must be individualized.
Renal Dosing: (General guidelines) Dialyzable (50% to 100%). Administer dose postdialysis or administer 2/3 normal dose as a supplemental dose postdialysis and follow levels. Supplied: Injection, solution: 50 mg/mL (2 mL, 4 mL); 250 mg/mL (2 mL, 4 mL) |
Gentamicin
| Dosing (Adults): Conventional dosing (Usual dosing range): 1 to 2.5 mg/kg/dose IM or IV every 8-12 hours.
Renal Dosing: (General guidelines for conventional dosing) |
Neomycin
| INDICATIONS Orally to prepare GI tract for surgery; topically to treat minor skin infections; treatment of diarrhea caused by E. coli ; adjunct in the treatment of hepatic encephalopathy; bladder irrigation Dosage Hepatic encephalopathy: 50-100 mg/kg/day in divided doses every 6-8 hours or 2.5-7 g/m 2 /day divided every 4-6 hours for 5-6 days not to exceed 12 g/day Children and Adults: Topical: Topical solutions containing 0.1% to 1% neomycin have been used for irrigation Preoperative intestinal antisepsis: 1 g each hour for 4 doses then 1 g every 4 hours for 5 doses; or 1 g at 1 PM, 2 PM, and 11 PM on day preceding surgery as an adjunct to mechanical cleansing of the bowel and oral erythromycin; or 6 g/day divided every 4 hours for 2-3 days Hepatic encephalopathy: 500-2000 mg every 6-8 hours or 4-12 g/day divided every 4-6 hours for 5-6 days Chronic hepatic insufficiency: 4 g/day for an indefinite period |
Streptomycin
| Dosing (Adults): Usual dose: 15 mg/kg (or 1 g) IM every 12 hours. Renal Dosing: Supplied: |
Tobramycin (tobrex®)
| Dosing (Adults): Conventional dosing (Usual dosing range): 1 to 2.5 mg/kg/dose IM or IV every 8-12 hours.
Renal Dosing: (General guidelines for conventional dosing) Supplied: Drug UPDATES: TOBI® PODHALER™ (tobramycin inhalation powder), for oral inhalation use Initial U.S. Approval: 2013 Mechanism of Action: Tobramycin is an aminoglycoside antimicrobial produced by Streptomyces tenebrarius. It acts primarily by disrupting protein synthesis leading to altered cell membrane permeability, progressive disruption of the cell envelope, and eventual cell death. Tobramycin has in vitro activity against Gram-negative bacteria including P. aeruginosa. It is bactericidal in vitro at peak concentrations equal to or slightly greater than the minimum inhibitory concentration (MIC). INDICATIONS AND USAGE: TOBI Podhaler is an antibacterial aminoglycoside indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa. HOW SUPPLIED: Inhalation powder: 28 mg in a capsule |
Reference(s)
National Institutes of Health, U.S. National Library of Medicine, DailyMed Database.
Provides access to the latest drug monographs submitted to the Food and Drug Administration (FDA). Please review the latest applicable package insert for additional information and possible updates. A local search option of this data can be found here.
