TOBI
tobramycin
tobramycin sulfate
Therapeutic class: Anti-infective
Pregnancy risk category B (inhalation, ophthalmic), D (parenteral)
FDA Box Warning
The following boxed warnings apply to parenteral administration only:
When giving drug by injection, observe patient closely for potential ototoxicity and nephrotoxicity. Rarely, nephrotoxicity doesn't emerge until first few days after therapy ends.
Neurotoxicity, manifested as both auditory and vestibular ototoxicity, can occur. Auditory changes are irreversible and usually bilateral. Eighth-nerve impairment and nephrotoxicity also may develop, mainly in patients with preexisting renal damage and in those with normal renal function who receive drug for longer periods or in higher doses than those recommended. Other neurotoxicity manifestations may include numbness, skin tingling, muscle twitching, and seizures. Risk of drug-induced hearing loss increases with degree of exposure to high peak or high trough drug blood levels. Patients who develop cochlear damage may lack symptoms during therapy to warn of eighth-nerve toxicity, and partial or total irreversible bilateral deafness may continue to develop after withdrawal.
Monitor renal and eighth-nerve function closely in patients with known or suspected renal impairment and in those whose renal functional initially is normal but who develop signs of renal dysfunction during therapy. Monitor peak and trough drug blood levels periodically during therapy; avoid levels above 12 mcg. Rising trough levels (above 2 mcg) may indicate tissue accumulation. Such accumulation, excessive peak levels, advanced age, and cumulative dose may contribute to ototoxicity and nephrotoxicity. Examine urine for decreased specific gravity and increased protein, cells, and casts. Measure blood urea nitrogen (BUN), serum creatinine, and creatinine clearance periodically. When feasible, obtain serial audiograms. Evidence of impairment of renal, vestibular, or auditory function warrants drug withdrawal or dosage adjustment.
Avoid concurrent or sequential use of other neurotoxic or nephrotoxic antibiotics, especially other aminoglycosides (such as amikacin, gentamicin, kanamycin, neomycin, and streptomycin), cephaloridine, cisplatin, colistin, polymyxin B, vancomycin, and viomycin. Advanced age and dehydration also increase risk.
Don't give concurrently with potent diuretics (such as furosemide and ethacrynic acid), because these drugs are also ototoxic. Also, I.V. diuretics may increase tobramycin toxicity by altering antibiotic serum and tissue levels.
Use drug cautiously in premature infants and neonates.
Drug may harm fetus when given to pregnant women.
Action
Interferes with protein synthesis in bacterial cell by binding to 30S ribosomal subunit
Availability
Injection: 10 mg/ml, 40 mg/ml, 1.2-g vial
Nebulizer solution: 300 mg/5 ml in 5-ml ampule
Ophthalmic ointment: 0.3%
Ophthalmic solution: 0.3%
Pediatric solution for injection: 20 mg/2 ml
Premixed I.V. solution: 60 mg in 50 ml normal saline, 80 mg in 100 ml normal saline
Indications and dosages
➣ Serious infections caused by susceptible organisms
Adults: 3 mg/kg/day I.V. or I.M. in evenly divided doses q 8 hours. For life-threatening infections, may increase up to 5 mg/kg/day I.V. or I.M. in three or four evenly divided doses, then reduce to 3 mg/kg/day as soon as possible.
Children older than 1 week: 6 to 7.5 mg/kg/day in three or four evenly divided doses, such as 2 to 2.5 mg/kg I.V. or I.M. q 8 hours or 1.5 to 1.9 mg/kg I.V. or I.M. q 6 hours
Neonates less than 1 week old: Up to 4 mg/kg/day I.V. or I.M. in evenly divided doses q 12 hours
➣ Pseudomonas aeruginosa in cystic fibrosis patients
Adults and children older than age 6: 300 mg inhalation b.i.d. (preferably q 12 hours but no less than 6 hours apart) for 28 days, then off for 28 days; then repeat cycle
➣ Ocular infections caused by susceptible organisms
Adults and children: For mild to moderate infections, apply a ribbon of ophthalmic ointment (approximately 1 cm) to infected eye two or three times daily, or instill one to two drops of ophthalmic solution into infected eye q 4 hours. For severe infections, apply ophthalmic ointment q 3 to 4 hours or instill two drops of ophthalmic solution into infected eye q 30 to 60 minutes; decrease dosing frequency when improvement occurs. Therapy should continue for at least 48 hours after infection is under control.
Dosage adjustment
• Renal impairment
Contraindications
• Hypersensitivity to drug, other aminoglycosides, bisulfites (with some products), or benzyl alcohol (in neonates, with some products)
Precautions
Use cautiously in:
• renal or hearing impairment, neuromuscular diseases, obesity
• elderly patients
• pregnant or breastfeeding patients
• neonates and premature infants.
Administration
• Know that premixed I.V. solution is ready to use and requires no further dilution. Don't mix with other drugs.
Don't use flexible container in series connections because of risk of air embolism.
• Dilute I.V. dose from vials in 50 to 100 ml of normal saline solution or dextrose 5% in water. For child, smaller volumes are needed.
• Infuse over at least 30 minutes. Flush line after administration.
• Give cephalosporins or penicillin, if ordered, 1 hour before or after tobramycin.
• Give inhalation doses by nebulizer over 10 to 15 minutes.
Adverse reactions
CNS: confusion, lethargy, headache, delirium, dizziness, vertigo
EENT: eye stinging (with ophthalmic form), ototoxicity, hearing loss, roaring in ears, tinnitus
GI: nausea, vomiting, diarrhea, stomatitis
GU: proteinuria, oliguria, nephrotoxicity
Hematologic: anemia, eosinophilia, leukocytosis, leukopenia, thrombocytopenia, granulocytopenia
Metabolic: hypocalcemia, hyponatremia, hypokalemia, hypomagnesemia
Musculoskeletal: muscle weakness
Respiratory: apnea
Skin: rash, urticaria, itching
Other: superinfection, fever, pain and irritation at injection site
Interactions
Drug-drug. Cephalosporins, vancomycin: increased risk of nephrotoxicity
Dimenhydrinate: masking of ototoxicity symptoms
General anesthetics, neuromuscular blockers: increased neuromuscular blockade and respiratory depression
Indomethacin: increased tobramycin trough and peak levels
Loop diuretics: increased risk of ototoxicity
Penicillins: physical incompatibility, tobramycin inactivation when mixed in same I.V. solution
Polypeptide anti-infectives: increased risk of respiratory paralysis and renal dysfunction
Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, bilirubin, BUN, creatinine, lactate dehydrogenase, nonprotein nitrogen, urine protein: increased levels
Calcium, granulocytes, hemoglobin, magnesium, platelets, potassium, sodium, white blood cells: decreased levels
Patient monitoring
• Draw sample for peak drug level 1 hour after I.M. or 30 minutes after I.V. administration. Draw sample for trough level just before next dose.
• Assess liver and kidney function tests.
• Monitor CBC with white cell differential.
• Closely monitor patient's hearing.
Patient teaching
Tell patient drug may cause hearing impairment and other serious adverse reactions, such as unusual bleeding or bruising. Instruct him to report these reactions at once.
• Advise patient to report new signs or symptoms of infection.
• With inhalation form, teach patient how to use nebulizer. Instruct him to administer dose over 10 to 15 minutes by breathing normally through mouthpiece while sitting or standing. Remind him to use only the hand-held nebulizer and compressor originally dispensed with drug. Advise him to use a nose clip to help him breathe through his mouth. If he uses other inhaled drugs, instruct him to take tobramycin last.
• Teach patient proper use of eye drops. Caution him not to touch dropper to eye or any other surface.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.
tobramycin
(toe-bra-mye-sin) tobramycin,Bethkis
(trade name),Nebcin
(trade name),TOBI
(trade name),TOBI Podhaler
(trade name)Classification
Therapeutic: anti infectivesPharmacologic: aminoglycosides
Indications
Action
Therapeutic effects
- Pseudomonas aeruginosa,
- Klebsiella pneumoniae,
- Escherichia coli,
- Proteus,
- Serratia,
- Acinetobacter,
- Staphylococcus aureus.
Pharmacokinetics
Time/action profile (blood levels†)
| ROUTE | ONSET | PEAK | DURATION |
| IM | rapid | 30–90 min | 6–24 hr |
| IV | rapid | end of infusion‡ | 6–24 hr |
Contraindications/Precautions
Adverse Reactions/Side Effects
Ear, Eye, Nose, Throat
- ototoxicity (vestibular and cochlear) (most frequent) Inhalation only:
- tinnitus
- voice alteration
Gastrointestinal
- pseudomembranous colitis (life-threatening)
Genitourinary
- nephrotoxicity (most frequent)
Fluid and Electrolyte
- hypomagnesemia
Musculoskeletal
- muscle paralysis (high parenteral doses)
Respiratory
- Inhalation only:
- bronchospasm
- wheezing
Miscellaneous
- hypersensitivity reactions
Interactions
Drug-Drug interaction
Inactivated by penicillins and cephalosporins when coadministered to patients with renal insufficiency.Possible respiratory paralysis after inhalation anesthetics orneuromuscular blockers.↑ risk of ototoxicity withloop diuretics.↑ risk of nephrotoxicity with othernephrotoxic drugs.Route/Dosage
Renal Impairment
Intramuscular Intravenous (Adults) 1 mg/kg initially, further dosing determined by blood level monitoring and assessment of renal function.Availability (generic available)
Nursing implications
Nursing assessment
- Assess patient for infection (vital signs, wound appearance, sputum, urine, stool, WBC) at beginning of and throughout therapy.
- Obtain specimens for culture and sensitivity before initiating therapy. First dose may be given before receiving results.
- Evaluate eighth cranial nerve function by audiometry before and throughout therapy. Hearing loss is usually in the high-frequency range. Prompt recognition and intervention are essential in preventing permanent damage. Also monitor for vestibular dysfunction (vertigo, ataxia, nausea, vomiting). Eighth cranial nerve dysfunction is associated with persistently elevated peak aminoglycoside levels. Aminoglycosides should be discontinued if tinnitus or subjective hearing loss occurs.
- Monitor intake and output and daily weight to assess hydration status and renal function.
- Assess patient for signs of superinfection (fever, upper respiratory infection, vaginal itching or discharge, increasing malaise, diarrhea).
- Monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly as a sign of pseudomembranous colitis. May begin up to several weeks following cessation of therapy.
- Lab Test Considerations: Monitor renal function by urinalysis, specific gravity, BUN, creatinine, and CCr before and during therapy.
- May cause ↑ BUN, AST, ALT, serum alkaline phosphatase, bilirubin, creatinine, and LDH concentrations.
- May cause ↓ serum calcium, magnesium, potassium, and sodium concentrations.
Blood levels should be monitored periodically during therapy. Timing of blood levels is important in interpreting results. Draw blood for peak levels 1 hr after IM injection and 30 min after a 30-min IV infusion is completed. Trough levels should be drawn just before next dose. Peak level should not exceed 10 mcg/mL; trough level should not exceed 2 mcg/mL.
Potential Nursing Diagnoses
Risk for infection (Indications)Disturbed sensory perception (auditory) (Side Effects)
Deficient knowledge, related to medication regimen (Patient/Family Teaching)
Implementation
- Keep patient well hydrated (1500–2000 mL/day) during therapy.
- Intramuscular: Administration should be deep into a well-developed muscle. Alternate injection sites.
Intravenous Administration
- pH: 3.0–6.5.
- Intermittent Infusion: Diluent: Dilute each dose of tobramycin in 50–100 mL of D5W, D10W, D5/0.9% NaCl, 0.9% NaCl, Ringer’s or lactated Ringer’s solution. Concentration: not >10 mg/mL. Pediatric doses may be diluted in proportionately smaller amounts. Stable for 24 hr at room temperature, 96 hr if refrigerated. Also available in commercially mixed piggyback injections.
- Rate: Infuse slowly over 30–60 min in both adult and pediatric patients.
- Y-Site Compatibility: acyclovir, aldesleukin, alfentanil, alprostadil, amifostine, aminophylline, amiodarone, amsacrine, anidulafungin, ascorbic acid, atropine, aztreonam, bivalirudin, bumetanide, buprenorphine, butorphanol, calcium chloride, calcium gluconate, carboplatin, caspofungin, chloramphenicol, ciprofloxacin, cisatracurium, cisplatin, clindamycin, cyanocobalamin, cyclophosphamide, cyclosporine, cytarabine, dactinomycin, daptomycin, dexmedetomidine, digoxin, diltiazem, diphenhyrdamine, dobutamine, docetaxel, dopamine, doripenem, doxorubicin hydrochloride, doxorubicin liposome, doxycycline, enalaprilat, ephedrine, epinephrine, epirubicin, epoetin alfa, ertapenem, esmolol, etoposide, etoposide phosphate, famotidine, fenoldopam, fentanyl, filgrastim, fluconazole, fludarabine, fluorouracil, foscarnet, furosemide, gemcitabine, gentamicin, glycopyrrolate, granisetron, hydromorphone, ifosfamide, imipenem/cilastatin, isoproterenol, ketorolac, labetalol, levofloxacin, lidocaine, linezolid, lorazepam, magnesium sulfate, mannitol, mechlorethamine, melphalan, meperidine, metaraminol, methcillin, methotrexate, methyldopate, methylprednisolone, metoclopramide, metoprolol, metronidazole, miconazole, midazolam, milrinone, minocycline, mitoxantrone, morphine, multiple vitamins, nalbuphine, naloxone, nicardipine, nitroglycerin, nitroprusside, norepinephrine, octreotide, ondansetron, oxaliplatin, oxytocin, paclitaxel, palonosetron, pantoprazole, papaverine, pentazocine, phenobarbital, phentolamine, phenylephrine, phytonadione, potassium chloride, procainamide, prochlorperazine, promethazine, propranolol, protamine, pyridoxime, quinapristin/dalfopristin, ranitidine, remifentanil, rituximab, rocuronium, sodium acetate, sodium bicarbonate, streptokinase, succinylcholine, sufentanil, tacrolimus, teniposide, theophylline, thiamine, thiotepa, tigecycline, tirofiban, tolazoline, trastuzumab, vancomycin, vasopressin, vecuronium, verapamil, vincristine, vinorelbine, voriconazole, zidovudine
- Y-Site Incompatibility: allopurinol, amphotericin B cholesteryl, amphotericin B colloidal, amphotericin B liposome, azathioprine, azithromycin, cefazolin, cefoperazone, cefotetan, ceftriaxone, dantrolene, dexamethasone, diazepam, diazoxide, folic acid, ganciclovir, heparin, hetastarch, indomethacin, oxacillin, pemetrexed, pentamidine, pentobarbital, phenytoin, piperacillin/tazobactam, propofol, sargramostim, trimethoprim/sulfamethoxazole
- Inhalation: Do not mix TOBI with dornase alpha in nebulizer.
- TOBI Podhaler capsules are not for oral use. Store capsules in blister until immediately before use. Use new Podhaler device provided with each weekly packet. Check to see capsule is empty after inhaling. If powder remains in capsule, repeat inhalation until capsule is empty.
Patient/Family Teaching
- Instruct patient to report signs of hypersensitivity, tinnitus, vertigo, hearing loss, rash, dizziness, or difficulty urinating.
- Advise patient of the importance of drinking plenty of liquids.
- Instruct patient to notify health care professional immediately if rash, diarrhea, abdominal cramping, fever, or bloody stools occur and not to treat with antidiarrheals without consulting health care professionals.
- Inhalation: Instruct patient to take inhalation twice daily as close to 12 hrs apart as possible; not <6 hrs apart. Solution is colorless to pale yellow and may darken with age without effecting quality. Administer over 15 min period using a hand-held PARI LC PLUS reusable nebulizer with a PARI VIOS (for Bethkis) or DeVibiss Pulmo Aide (for TOBI) compressor. Instruct patient on multiple therapies to take others first and use tobramycin last. Tobramycin-induced bronchospasm may be reduced if tobramycin is administered following bronchodilators. Instruct patient to sit or stand upright during inhalation and breathe normally through mouthpiece of nebulizer. Nose clips may help patient breathe through mouth. Store at room temperature for up to 28 days. Advise patient to disinfect the nebulizer parts (except tubing) by boiling them in water for a full 10 minutes every other treatment day.
- Instruct patient in correct technique for use of TOBI Podhaler. Wipe mouthpiece with clean, dry cloth after use; do not wash with water.
- Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Evaluation/Desired Outcomes
- Resolution of the signs and symptoms of infection. If no response is seen within 3–5 days, new cultures should be taken.