Tobramycin Inhalation

1 INDICATIONS AND USAGE Tobramycin Inhalation Solution is indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa . Safety and efficacy have not been demonstrated in patients under the age of six years, patients with FEV 1 less than 40% or greater than 80% predicted, or patients colonized with Burkholderia cepacia [see Clinical Studies ( 14 )] . Tobramycin Inhalation Solution is an inhaled aminoglycoside antibacterial indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa . ( 1 ) Safety and efficacy have not been demonstrated in patients under the age of six years, patients with a forced expiratory volume in one second (FEV 1 ) less than 40% or greater than 80% predicted, or patients colonized with Burkholderia cepacia . ( 1 )

2 DOSAGE AND ADMINISTRATION For oral inhalation only ( 2.1 ) Administer the entire contents of one ampule twice daily by oral inhalation in repeated cycles of 28 days on drug, followed by 28 days off drug. ( 2.1 ) 2.1 Dosage Tobramycin Inhalation Solution is for oral inhalation only [see Dosage and Administration ( 2.2 )] . The recommended dosage of Tobramycin Inhalation Solution for patients six years of age and older is to administer one single-use ampule (300 mg/4 mL) twice daily by oral inhalation in repeated cycles of 28 days on drug, followed by 28 days off drug. The doses should be taken as close to 12 hours apart as possible and not less than 6 hours apart. The 300 mg/4 mL dose of Tobramycin Inhalation Solution is the same for patients regardless of age or weight. Tobramycin Inhalation Solution has not been studied in patients less than six years old. If patients miss a dose, they should take it as soon as possible anytime up to 6 hours prior to their next scheduled dose. If less than 6 hours remain before the next dose, wait until their next scheduled dose. 2.2 Administration Instructions Tobramycin Inhalation Solution is administered by oral inhalation using a hand-held PARI LC PLUS Reusable Nebulizer with a PARI Vios Air compressor over an approximately 15 minute period and until sputtering from the output of the nebulizer has occurred for at least one minute. Tobramycin Inhalation Solution should not be diluted or mixed with dornase alfa or other medications in the nebulizer. Tobramycin Inhalation Solution is not for subcutaneous, intravenous, or intrathecal administration. Further patient instructions on how to administer Tobramycin Inhalation Solution are provided in the Patient’s Instructions for Use [see Patient Counseling Information ( 17 )]. Tobramycin Inhalation Solution should not be used if it is cloudy, if there are particles in the solution, or if it has been stored at room temperature for more than 28 days.

4 CONTRAINDICATIONS Tobramycin Inhalation Solution is contraindicated in patients with a known hypersensitivity to any aminoglycoside. Tobramycin Inhalation Solution is contraindicated in patients with a known hypersensitivity to any aminoglycoside. ( 4 )

5 WARNINGS AND PRECAUTIONS Caution should be exercised when prescribing Tobramycin Inhalation Solution to patients with known or suspected auditory, vestibular, renal, or neuromuscular dysfunction. ( 5.1 , 5.2 , 5.3 and 5.5 ) Aminoglycoside may aggravate muscle weakness because of a potential curare-like effect on neuromuscular function. ( 5.3 ) Bronchospasm can occur with inhalation of Tobramycin Inhalation Solution. ( 5.4 ) Audiograms, serum concentration, and renal function should be monitored as appropriate. ( 5.2 and 5.5 ) Fetal harm can occur when aminoglycosides are administered to a pregnant woman. Apprise women of the potential hazard to the fetus. ( 5.6 ) 5.1 Ototoxicity Ototoxicity with use of Tobramycin Inhalation Solution Caution should be exercised when prescribing Tobramycin Inhalation Solution to patients with known or suspected auditory or vestibular dysfunction. Findings related to ototoxicity as measured by audiometric evaluations and auditory adverse event reports were similar between Tobramycin Inhalation Solution and placebo in controlled clinical trials. Hearing loss was reported in two (1.1%) Tobramycin Inhalation Solution-treated patients and in one (0.9%) placebo-treated patient during clinical studies. Additionally, dizziness and vertigo, both of which may be manifestations of vestibular forms Tobramycin Inhalation Solution of ototoxicity, were observed in similar numbers of Tobramycin Inhalation Solution- and placebo-treated patients. Dizziness occurred in two (1.1%) Tobramycin Inhalation Solution-treated patients and one (0.9%) placebo-treated patient and vertigo occurred in two (1.1%) Tobramycin Inhalation Solution-treated patients versus no placebo patients in clinical studies. None of the Tobramycin Inhalation Solution patients discontinued their therapy due to hearing loss, dizziness or vertigo. Tinnitus may be a sentinel symptom of ototoxicity. No reports of tinnitus occurred in patients during clinical studies with Tobramycin Inhalation Solution, but because it has been observed with inhaled tobramycin solutions [see Adverse Reactions ( 6.2 )] , onset of this symptom warrants caution. Ototoxicity, manifested as both auditory and vestibular toxicity, has been reported with parenteral aminoglycosides. Vestibular toxicity may be manifested by vertigo, ataxia or dizziness. Patients with known or suspected auditory or vestibular dysfunction should be closely monitored when taking Tobramycin Inhalation Solution. Monitoring may include obtaining audiometric evaluations and serum tobramycin levels. If ototoxicity is noted, the patient should be managed as medically appropriate, including potentially discontinuing Tobramycin Inhalation Solution. Risk of Ototoxicity Due to Mitochondrial DNA Variants Cases of ototoxicity with aminoglycosides have been observed in patients with certain variants in the mitochondrially encoded 12S rRNA gene (MT-RNR1) , particularly the m.1555A>G variant. Ototoxicity occurred in some patients even when their aminoglycoside serum levels were within the recommended range. Mitochondrial DNA variants are present in less than 1% of the general US population, and the proportion of the variant carriers who may develop ototoxicity as well as the severity of ototoxicity is unknown. In case of known maternal history of ototoxicity due to aminoglycoside use or a known mitochondrial DNA variant in the patient, consider alternative treatments other than aminoglycosides unless the increased risk of permanent hearing loss is outweighed by the severity of infection and lack of safe and effective alternative therapies. 5.2 Nephrotoxicity Caution should be exercised when prescribing Tobramycin Inhalation Solution to patients with known or suspected renal dysfunction. Nephrotoxicity was not seen during Tobramycin Inhalation Solution clinical studies but has been associated with aminoglycosides as a class. Patients with known or suspected renal dysfunction or taking concomitant nephrotoxic drugs along with Tobramycin Inhalation Solution should have serum concentrations of tobramycin and laboratory measurements of renal function obtained at the discretion of the treating physician. If nephrotoxicity develops, the patient should be managed as medically appropriate, including potentially discontinuing Tobramycin Inhalation Solution until serum concentrations fall below 2 mcg/mL. Twenty-six (14%) Tobramycin Inhalation Solution patients and 15 (13%) placebo patients had increases in serum creatinine of at least 50% over baseline. Follow-up values were obtained for 17 of the 26 Tobramycin Inhalation Solution patients, all of which decreased to serum creatinine values that were within normal laboratory ranges. Patients who experience an increase in serum creatinine during treatment with Tobramycin Inhalation Solution should have their renal function closely monitored. 5.3 Neuromuscular Disorders Tobramycin Inhalation Solution should be used cautiously in patients with muscular disorders. Aminoglycosides, including tobramycin, may aggravate muscle weakness because of a potential curare-like effect on neuromuscular function. Neuromuscular blockade, respiratory failure, and prolonged respiratory paralysis may occur more commonly in patients with underlying neuromuscular disorders, such as myasthenia gravis or Parkinson’s disease. Prolonged respiratory paralysis may also occur in patients receiving concomitant neuromuscular blocking agents. If neuromuscular blockade occurs, it may be reversed by the administration of calcium salts but mechanical assistance may be necessary. 5.4 Bronchospasm Bronchospasm has been reported with inhalation of tobramycin. In clinical studies with Tobramycin Inhalation Solution, bronchospasm was observed in one (0.5%) Tobramycin Inhalation Solution-treated patient and in no placebo-treated patients. Wheezing occurred in ten (5%) Tobramycin Inhalation Solution-treated patients and four (4%) placebo-treated patients. Bronchospasm and wheezing should be treated as medically appropriate. 5.5 Laboratory Tests Audiograms Clinical studies of inhaled tobramycin solutions did not identify hearing loss using audiometric tests which evaluated hearing up to 8000 Hz. Physicians should consider an audiogram for patients who show any evidence of auditory dysfunction, or who are at increased risk for auditory dysfunction. Tinnitus may be a sentinel symptom of ototoxicity, and therefore the onset of this symptom warrants caution. Serum Concentrations In patients with normal renal function treated with Tobramycin Inhalation Solution, serum tobramycin concentrations range from approximately 0.06-1.89 mcg/mL one hour after dose administration and do not require routine monitoring. Serum concentrations of tobramycin in patients with renal dysfunction or patients treated with concomitant parenteral tobramycin should be monitored at the discretion of the treating physician [see Clinical Pharmacology ( 12.3 )] . The serum concentration of tobramycin should only be monitored through venipuncture and not finger prick blood sampling. Contamination of the skin of the fingers with tobramycin may lead to falsely increased measurements of serum levels of the drug. This contamination cannot be completely avoided by hand washing before testing. Renal Function The clinical studies of Tobramycin Inhalation Solution did not reveal any imbalance in the percentage of patients who experienced at least a 50% rise in serum creatinine from baseline in either the Tobramycin Inhalation Solution group (n=26, 14%) or the placebo group (n=15, 13%). Laboratory tests of urine and renal function should be conducted at the discretion of the treating physician. 5.6 Embryo-Fetal Toxicity Aminoglycosides can cause fetal harm when administered to a pregnant woman. Aminoglycosides cross the placenta, and streptomycin has been associated with several reports of total, irreversible, bilateral congenital deafness in pediatric patients exposed in utero . However, systemic absorption of tobramycin following inhaled administration is expected to be minimal [see Clinical Pharmacology ( 12.3 )] . Patients who use Tobramycin Inhalation Solution during pregnancy, or become pregnant while taking Tobramycin Inhalation Solution should be apprised of the potential hazard to the fetus [see Use in Specific Populations ( 8.1 )] . 5.7 Concomitant Use of Systemic Aminoglycosides Patients receiving concomitant Tobramycin Inhalation Solution and parenteral aminoglycoside therapy should be monitored as clinically appropriate for toxicities associated with aminoglycosides as a class. Serum tobramycin levels should be monitored.

7 DRUG INTERACTIONS Concurrent and/or sequential use of Tobramycin Inhalation Solution with other drugs with neurotoxic, nephrotoxic or ototoxic potential should be avoided. ( 7.1 ) Tobramycin Inhalation Solution should not be administered concomitantly with ethacrynic acid, furosemide, urea, or intravenous mannitol. ( 7.2 ) 7.1 Drugs with Neurotoxic, Nephrotoxic, or Ototoxic Potential Concurrent and/or sequential use of Tobramycin Inhalation Solution with other drugs with neurotoxic, nephrotoxic, or ototoxic potential should be avoided. 7.2 Diuretics Some diuretics can enhance aminoglycoside toxicity by altering antibiotic concentrations in serum and tissue. Therefore, Tobramycin Inhalation Solution should not be administered concomitantly with ethacrynic acid, furosemide, urea, or intravenous mannitol. The interaction between inhaled mannitol and Tobramycin Inhalation Solution has not been evaluated.

6 ADVERSE REACTIONS Common adverse reactions (more than 5%) occurring more frequently in Tobramycin Inhalation Solution patients are forced expiratory volume decreased, rales, red blood cell sedimentation rate increased, and dysphonia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Prasco Laboratories at 1-866-525-0688 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of drugs cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect exposure to Tobramycin Inhalation Solution in two placebo-controlled studies in 305 cystic fibrosis patients. Patients receiving Tobramycin Inhalation Solution ranged in age from 6 to 31 years. In Study 1, an eight week study, 29 patients received Tobramycin Inhalation Solution versus 30 patients who received placebo for a total of four weeks on drug and four weeks off drug. All patients were ≤ 30 years of age (mean age 12.6 years) and 46% were females. 52.5% of patients were 6 to 12 years of age while 30.5% of patients were 13-17 years old. Only 16.5% of patients were adults (> 17 years old). Eighty percent (80%) of patients were chronically colonized with Pseudomonas aeruginosa while 20.3% of patients were initially or intermittently colonized with Pseudomonas aeruginosa during the study. More patients in the placebo group discontinued/dropped out of Study 1 than in the Tobramycin Inhalation Solution group (23% [7/30] vs 3.4% [1/29], respectively). Five patients in the placebo group compared to none in the Tobramycin Inhalation Solution group discontinued/dropped out because of treatment-emergent adverse events (TEAEs) such as pulmonary exacerbations and respiratory disorders. In Study 2, a 24 week study, 161 patients received Tobramycin Inhalation Solution versus 85 patients who received placebo in alternating four week on-off cycles for three cycles. All patients were ≤ 46 years of age (mean age 14.8 years) and 45% were females. 41% of patients were 6-12 years old while 29% of patients were 13-17 years old. Only 30% were adults (>17 years). Eighty-seven percent (87%) of patients were chronically colonized with P. aeruginosa . Only 13% were either initially or intermittently colonized with P. aeruginosa during the study. More patients in the placebo group discontinued/dropped out of Study 2 than in the Tobramycin Inhalation Solution group (9.4% [8/85] vs 4.3% [7/161], respectively). Of these, 3 patients in the Tobramycin Inhalation Solution group (1.9%) compared to 2 patients in the placebo group (2.4%) withdrew due to a TEAE. The most common TEAEs causing patients to discontinue from the study drug are respiratory, thoracic, and mediastinal disorders. The most common adverse experiences reported were respiratory disorders, consistent with the underlying disease in the patient population being evaluated and these were similarly distributed between both Tobramycin Inhalation Solution- and placebo-treated patients. The following adverse reactions were reported in at least 5% of Tobramycin Inhalation Solution-treated patients and at rates ≥ 2% more common compared to the placebo-treated patients: decreased forced expiratory volume, rales, red blood cell sedimentation rate increased, and dysphonia ( Table 1 ). Table 1: Patients with Selected Treatment-Emergent Adverse Reactions Occurring in ≥ 2% of Tobramycin Inhalation Solution Patients Adverse Reactions Tobramycin Inhalation Solution N=190 (%) Placebo N=115 (%) Forced expiratory volume decreased 59 (31%) 33 (29%) Rales 36 (19%) 18 (16%) Red blood cell sedimentation rate increased 16 (8%) 6 (5%) Dysphonia 11 (6%) 2 (2%) Wheezing 10 (5%) 4 (4%) Epistaxis 6 (3%) 0 Pharyngolaryngeal pain 5 (3%) 2 (2%) Bronchitis 5 (3%) 1 (1%) Tonsillitis 4 (2%) 0 Diarrhea 3 (2%) 1 (1%) Eosinophilia 3 (2%) 0 Immunoglobulins increased 3 (2%) 0 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of tobramycin inhalation solution. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Ear and labyrinth disorders: Hearing loss, Tinnitus [see Warnings and Precautions ( 5.1 )] Skin and subcutaneous tissue disorders : Hypersensitivity, pruritus, urticaria, rash Nervous system disorders : Aphonia, dysgeusia Respiratory, thoracic, and mediastinal disorders: Bronchospasm [see Warnings and Precautions ( 5.4 )] , oropharyngeal pain Metabolism and Nutrition Disorders: Decreased appetite

8.1 Pregnancy Risk Summary Aminoglycosides can cause fetal harm. Published literature reports that use of streptomycin, an aminoglycoside, can cause total, irreversible, bilateral congenital deafness when administered to a pregnant woman [Warnings and Precautions ( 5.6 )] . Although there are no available data on use of Tobramycin Inhalation Solution in pregnant women to be able to inform a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes, systemic absorption of tobramycin following inhaled administration is expected to be minimal [see Clinical Pharmacology ( 12.3 )] . There are risks to the mother associated with cystic fibrosis in pregnancy (see Clinical Considerations) . In animal reproduction studies with subcutaneous administration of tobramycin in pregnant rats and rabbits during organogenesis there were no adverse developmental outcomes; however, ototoxicity was not evaluated in the offspring from these studies (see Data ) . Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Cystic fibrosis may increase the risk for preterm delivery. Data Animal Data No reproduction toxicology studies have been conducted with inhaled tobramycin. However, subcutaneous administration of tobramycin at doses of up to 100 (rat) or 20 (rabbit) mg/kg/day during organogenesis was not associated with adverse developmental outcomes. Subcutaneous doses of tobramycin ≥ 40mg/kg/day were severely maternally toxic to rabbits and precluded the evaluation of adverse developmental outcomes. Ototoxicity was not evaluated in offspring during nonclinical reproductive toxicity studies with tobramycin.