WARNINGS
Included as part of the PRECAUTIONS section.
PRECAUTIONS
Ototoxicity
Caution should be exercised when prescribing BETHKIS 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
BETHKIS and placebo in controlled clinical trials. Hearing loss was reported in
two (1.1%) BETHKIS-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 of ototoxicity, were observed in similar
numbers of BETHKIS- and placebo-treated patients. Dizziness occurred in two
(1.1%) BETHKIS-treated patients and one (0.9%) placebo-treated patient and vertigo
occurred in two (1.1%) BETHKIStreated
patients versus no placebo patients in clinical studies. None of the BETHKIS
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 BETHKIS,
but because it has been observed with inhaled tobramycin solutions [see ADVERSE
REACTIONS], 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.
Nephrotoxicity
Caution should be exercised when prescribing BETHKIS to
patients with known or suspected renal dysfunction.
Nephrotoxicity was not seen during BETHKIS clinical
studies but has been associated with aminoglycosides as a class. If
nephrotoxicity occurs in a patient receiving BETHKIS, therapy should be discontinued
until serum concentrations fall below 2 mcg/mL.
Twenty-six (14%) BETHKIS 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 BETHKIS 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
BETHKIS should have their renal function closely monitored.
Neuromuscular Disorders
BETHKIS should be used cautiously in patients with
muscular disorders, such as myasthenia gravis or Parkinson's disease, since
aminoglycosides may aggravate muscle weakness because of a potential curare-like
effect on neuromuscular function.
Bronchospasm
Bronchospasm has been reported with inhalation of
tobramycin. In clinical studies with BETHKIS, bronchospasm was observed in one
(0.5%) BETHKIS-treated patient and in no placebo-treated patients. Wheezing
occurred in ten (5%) BETHKIS-treated patients and four (4%) placebo-treated
patients. Bronchospasm and wheezing should be treated as medically appropriate.
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
BETHKIS, 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].
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 BETHKIS 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 BETHKIS 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.
Use In Pregnancy
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. Patients who use BETHKIS
during pregnancy, or become pregnant while taking BETHKIS should be apprised of
the potential hazard to the fetus.
Patient Counseling Information
Advise the patient to read the FDA-approved patient
labeling (PATIENT INFORMATION and Instructions for Use).
Information For Patients
Information on the long term efficacy and safety of
BETHKIS is limited. There is no information in patients with severe cystic
fibrosis (FEV1 < 40% predicted).
Patients should be advised to complete a full 28-day
course of BETHKIS, even if they are feeling better. After 28 days of therapy,
patients should stop BETHKIS therapy for the next 28 days, and then resume
therapy for the next 28 day on and 28 day off cycle.
For patients taking several different inhaled medications
and/or performing chest physiotherapy, advise the patient regarding the order
they should take the therapies. It is recommended that BETHKIS be taken last.
BETHKIS is to be used with the PARI LC PLUS reusable
nebulizer and the PARI VIOS air compressor. Refer to the manufacturer's
instructions for care and use of the nebulizer and compressor.
Ototoxicity
Inform patients that ototoxicity, as measured by
complaints of hearing loss or tinnitus, was reported by patients treated with
tobramycin. Physicians should consider an audiogram at baseline, particularly
for patients at increased risk of auditory dysfunction.
If a patient reports tinnitus or hearing loss during
BETHKIS therapy, the physician should refer that patient for audiological
assessment.
Patients should be reminded that vestibular toxicity may
manifest as vertigo, ataxia, or dizzines.
Bronchospasm
Inform patients that bronchospasm can occur with
inhalation of tobramycin.
Risks Associated With Aminoglycosides
Inform patients of adverse reactions associated with
aminoglycosides such as nephrotoxicity and neuromuscular disorders.
Laboratory Tests
Inform patients of the need to monitor hearing, serum
concentrations of tobramycin, or renal function as necessary during treatment
with BETHKIS.
Pregnancy
Inform patients that aminoglycosides can cause fetal harm
when administered to a pregnant woman. Advise them to inform their doctor if
they are pregnant, become pregnant, or plan to become pregnant.
Storage Instructions
You should store BETHKIS ampules in a refrigerator (36-46
°F or 2-8 °C). However, when you don't have a refrigerator available (e.g.,
transporting your BETHKIS), you may store the foil pouches (opened or unopened)
at room temperature (up to 77 °F/25 °C) for up to 28 days.
BETHKIS is light sensitive; unopened ampules should be
returned to the foil pouch. Avoid exposing BETHKIS ampules to intense light.
Unrefrigerated BETHKIS, which is normally colorless to pale yellow, may darken
with age; however, the color change does not indicate any change in the quality
of the product.
You should not use BETHKIS 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. You should not use BETHKIS beyond the expiration date stamped
on the ampule.
Additional Information
Nebulizers and Compressors: 1-800-327-8632
BETHKIS: 1-888-661-9260
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
A two-year rat inhalation toxicology study to assess
carcinogenic potential of an inhaled solution of tobramycin has been completed.
Rats were exposed to tobramycin for up to 1.5 hours per day for 95 weeks. Serum
levels of tobramycin up to 35 mcg/mL were measured in rats, 35x the average 1 mcg/mL
exposure levels observed in cystic fibrosis patients in clinical trials. There
was no drugrelated increase in the incidence of any variety of tumors.
Additionally, tobramycin has been evaluated for
genotoxicity in a battery of in vitro and in vivo tests. The Ames bacterial
reversion test, conducted with five tester strains, failed to show a
significant increase in revertants with or without metabolic activation in all
strains. Tobramycin was negative in the mouse lymphoma forward mutation assay,
did not induce chromosomal aberrations in Chinese hamster ovary cells, and was
negative in the mouse micronucleus test.
Subcutaneous administration of up to 100 mg/kg of
tobramycin did not affect mating behavior or cause impairment of fertility in
male or female rats.
Use In Specific Populations
Pregnancy
Teratogenic Effects
Pregnancy Category D
No reproduction toxicology studies have been conducted
with inhaled tobramycin. However, subcutaneous administration of tobramycin at
doses of 100 mg or 20 mg/kg/day during organogenesis was not teratogenic in
rats or rabbits, respectively. Subcutaneous doses of tobramycin ≥
40mg/kg/day were severely maternally toxic to rabbits and precluded the
evaluation of teratogenicity. Aminoglycosides can cause fetal harm (e.g.,
congenital deafness) when administered to a pregnant woman. Ototoxicity was not
evaluated in offspring during nonclinical reproduction toxicity studies with tobramycin.
If tobramycin is used during pregnancy, or if the patient becomes pregnant
while taking tobramycin, the patient should be apprised of the potential hazard
to the fetus.
Labor And Delivery
The safety and efficacy of BETHKIS have not been studied
in the puerperal patient.
Nursing Mothers
It is not known if tobramycin will reach sufficient
concentrations after administration by inhalation to be excreted in human
breast milk. Because of the potential for ototoxicity and nephrotoxicity in
infants, a decision should be made whether to terminate nursing or discontinue
tobramycin therapy, taking into account the importance of the drug to the
mother.
Pediatric Use
The safety and efficacy of BETHKIS have not been studied
in pediatric cystic fibrosis patients under six years of age.
Geriatric Use
Clinical studies of BETHKIS did not include patients aged
65 years and over. Tobramycin is known to be substantially excreted by the
kidney, and the risk of adverse reactions to this drug may be greater in patients
with impaired renal function. Because elderly patients are more likely to have
decreased renal function, it may be useful to monitor renal function [see WARNINGS
AND PRECAUTIONS].
Renal Impairment
Tobramycin is primarily excreted unchanged in the urine
and renal function is expected to affect the exposure of tobramycin. The risk
of adverse reactions to this drug may be greater in patients with impaired
renal function. Patients with serum creatinine > 2mg/dL and blood urea
nitrogen (BUN) > 40mg/dL have not been included in clinical studies and
there are no data in this population to support a recommendation for or against
dose adjustment [see WARNINGS AND PRECAUTIONS].
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.