WARNINGS
Included as part of the PRECAUTIONS section.
PRECAUTIONS
Addiction, Abuse, And Misuse
SUBOXONE sublingual tablets contain buprenorphine, a
schedule III controlled substance that can be abused in a manner similar to
other opioids, legal or illicit. Prescribe and dispense buprenorphine with
appropriate precautions to minimize risk of misuse, abuse, or diversion, and
ensure appropriate protection from theft, including in the home. Clinical
monitoring appropriate to the patient's level of stability is essential.
Multiple refills should not be prescribed early in treatment or without
appropriate patient follow-up visits [see Drug Abuse And Dependence].
Risk Of Respiratory And Central Nervous System (CNS)
Depression
Buprenorphine has been associated with life-threatening respiratory
depression and death. Many, but not all, post-marketing reports regarding coma
and death involved misuse by self-injection or were associated with the concomitant
use of buprenorphine and benzodiazepines or other CNS depressant, including
alcohol. Warn patients of the potential danger of self-administration of
benzodiazepines or other CNS depressants while under treatment with SUBOXONE
sublingual tablets [see Managing Risks from Concomitant Use of Benzodiazepine or Other CNS Depressants, DRUG INTERACTIONS].
Use SUBOXONE sublingual tablets with caution in patients
with compromised respiratory function (e.g., chronic obstructive pulmonary
disease, cor pulmonale, decreased respiratory reserve, hypoxia, hypercapnia, or
preexisting respiratory depression).
Managing Risks From Concomitant Use Of Benzodiazepine Or
Other CNS Depressants
Concomitant use of buprenorphine and benzodiazepines or
other CNS depressants increases the risk of adverse reactions including
overdose and death. Medication-assisted treatment of opioid use disorder,
however, should not be categorically denied to patients taking these drugs.
Prohibiting or creating barriers to treatment can pose an even greater risk of
morbidity and mortality due to the opioid use disorder alone.
As a routine part of orientation to buprenorphine treatment,
educate patients about the risks of concomitant use of benzodiazepines,
sedatives, opioid analgesics, and alcohol.
Develop strategies to manage use of prescribed or illicit
benzodiazepines or other CNS depressants at initiation of buprenorphine treatment,
or if it emerges as a concern during treatment. Adjustments to induction procedures
and additional monitoring may be required. There is no evidence to support dose
limitations or arbitrary caps of buprenorphine as a strategy to address
benzodiazepine use in buprenorphine-treated patients. However, if a patient is
sedated at the time of buprenorphine dosing, delay or omit the buprenorphine
dose if appropriate.
Cessation of benzodiazepines or other CNS depressants is
preferred in most cases of concomitant use. In some cases, monitoring in a
higher level of care for taper may be appropriate. In others, gradually
tapering a patient off of a prescribed benzodiazepine or other CNS depressant
or decreasing to the lowest effective dose may be appropriate.
For patients in buprenorphine treatment, benzodiazepines
are not the treatment of choice for anxiety or insomnia. Before co-prescribing
benzodiazepines, ensure that patients are appropriately diagnosed and consider
alternative medications and non-pharmacologic treatments to address anxiety or
insomnia. Ensure that other healthcare providers prescribing benzodiazepines or
other CNS depressants are aware of the patient's buprenorphine treatment and
coordinate care to minimize the risks associated with concomitant use.
In addition, take measures to confirm that patients are
taking their medications as prescribed and are not diverting or supplementing
with illicit drugs. Toxicology screening should test for prescribed and illicit
benzodiazepines [see DRUG INTERACTIONS].
Unintentional Pediatric Exposure
Buprenorphine can cause severe, possibly fatal,
respiratory depression in children who are accidentally exposed to it. Store
buprenorphine-containing medications safely out of the sight and reach of
children and destroy any unused medication appropriately [see PATIENT INFORMATION].
Neonatal Opioid Withdrawal Syndrome
Neonatal opioid withdrawal syndrome (NOWS) is an expected
and treatable outcome of prolonged use of opioids during pregnancy, whether
that use is medically-authorized or illicit. Unlike opioid withdrawal syndrome
in adults, NOWS may be life-threatening if not recognized and treated in the
neonate. Healthcare professionals should observe newborns for signs of NOWS and
manage accordingly [see Use In Specific Populations].
Advise pregnant women receiving opioid addiction
treatment with SUBOXONE sublingual tablet of the risk of neonatal opioid
withdrawal syndrome and ensure that appropriate treatment will be available [see
Use In Specific Populations]. This risk must be balanced against
the risk of untreated opioid addiction which often results in continued or
relapsing illicit opioid use and is associated with poor pregnancy outcomes.
Therefore, prescribers should discuss the importance and benefits of management
of opioid addiction throughout pregnancy.
Adrenal Insufficiency
Cases of adrenal insufficiency have been reported with
opioid use, more often following greater than one month of use. Presentation of
adrenal insufficiency may include non-specific symptoms and signs including nausea,
vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. If
adrenal insufficiency is suspected, confirm the diagnosis with diagnostic
testing as soon as possible. If adrenal insufficiency is diagnosed, treat with
physiologic replacement doses of corticosteroids. Wean the patient off of the
opioid to allow adrenal function to recover and continue corticosteroid
treatment until adrenal function recovers. Other opioids may be tried as some
cases reported use of a different opioid without recurrence of adrenal insufficiency.
The information available does not identify any particular opioids as being
more likely to be associated with adrenal insufficiency.
Risk Of Opioid Withdrawal With Abrupt Discontinuation
Buprenorphine is a partial agonist at the mu-opioid
receptor and chronic administration produces physical dependence of the
opioid-type, characterized by withdrawal signs and symptoms upon abrupt
discontinuation or rapid taper. The withdrawal syndrome is typically milder
than seen with full agonists and may be delayed in onset [see Drug Abuse And
Dependence]. When discontinuing SUBOXONE sublingual tablet, gradually taper
the dosage [see DOSAGE AND ADMINISTRATION].
Risk Of Hepatitis, Hepatic Events
Cases of cytolytic hepatitis and hepatitis with jaundice
have been observed in individuals receiving buprenorphine in clinical trials
and through post-marketing adverse event reports. The spectrum of abnormalities
ranges from transient asymptomatic elevations in hepatic transaminases to case
reports of death, hepatic failure, hepatic necrosis, hepatorenal syndrome, and
hepatic encephalopathy. In many cases, the presence of pre-existing liver
enzyme abnormalities, infection with hepatitis B or hepatitis C virus, concomitant
usage of other potentially hepatotoxic drugs, and ongoing injecting drug use
may have played a causative or contributory role. In other cases, insufficient
data were available to determine the etiology of the abnormality. Withdrawal of
buprenorphine has resulted in amelioration of acute hepatitis in some cases; however,
in other cases no dose reduction was necessary. The possibility exists that
buprenorphine had a causative or contributory role in the development of the
hepatic abnormality in some cases. Liver function tests, prior to initiation of
treatment is recommended to establish a baseline. Periodic monitoring of liver function
during treatment is also recommended. A biological and etiological evaluation
is recommended when a hepatic event is suspected. Depending on the case,
SUBOXONE sublingual tablet may need to be carefully discontinued to prevent
withdrawal signs and symptoms and a return by the patient to illicit drug use,
and strict monitoring of the patient should be initiated.
Hypersensitivity Reactions
Cases of hypersensitivity to buprenorphine and naloxone
containing products have been reported both in clinical trials and in the
post-marketing experience. Cases of bronchospasm, angioneurotic edema, and anaphylactic
shock have been reported. The most common signs and symptoms include rashes,
hives, and pruritus. A history of hypersensitivity to buprenorphine or naloxone
is a contraindication to the use of SUBOXONE sublingual tablet.
Precipitation Of Opioid Withdrawal Signs And Symptoms
Because it contains naloxone, SUBOXONE sublingual tablet
is highly likely to produce marked and intense withdrawal signs and symptoms if
misused parenterally by individual dependent on full opioid agonists such as heroin,
morphine, or methadone. Because of the partial agonist properties of
buprenorphine, SUBOXONE sublingual tablet may precipitate opioid withdrawal
signs and symptoms in such persons if administered sublingually before the
agonist effects of the opioid have subsided.
Risk Of Overdose In Opioid Naïve Patients
There have been reported deaths of opioid naïve
individuals who received a 2 mg dose of buprenorphine as a sublingual tablet
for analgesia. SUBOXONE sublingual tablet is not appropriate as an analgesic.
Use In Patients With Impaired Hepatic Function
Buprenorphine/naloxone products are not recommended in
patients with severe hepatic impairment and may not be appropriate for patients
with moderate hepatic impairment. The doses of buprenorphine and naloxone in
this fixed-dose combination product cannot be individually titrated, and
hepatic impairment results in a reduced clearance of naloxone to a much greater
extent than buprenorphine. Therefore, patients with severe hepatic impairment
will be exposed to substantially higher levels of naloxone than patients with
normal hepatic function. This may result in an increased risk of precipitated
withdrawal at the beginning of treatment (induction) and may interfere with
buprenorphine's efficacy throughout treatment. In patients with moderate hepatic
impairment, the differential reduction of naloxone clearance compared to
buprenorphine clearance is not as great as in subjects with severe hepatic
impairment. However, buprenorphine/naloxone products are not recommended for
initiation of treatment (induction) in patients with moderate hepatic
impairment due to the increased risk of precipitated withdrawal.
Buprenorphine/naloxone products may be used with caution for maintenance
treatment in patients with moderate hepatic impairment who have initiated
treatment on a buprenorphine product without naloxone. However, patients should
be carefully monitored and consideration given to the possibility of naloxone
interfering with buprenorphine's efficacy [see Use In Specific Populations].
Impairment Of Ability To Drive Or Operate Machinery
SUBOXONE sublingual tablet may impair the mental or
physical abilities required for the performance of potentially dangerous tasks
such as driving a car or operating machinery, especially during treatment
induction and dose adjustment. Caution patients about driving or operating
hazardous machinery until they are reasonably certain that SUBOXONE sublingual
tablet therapy does not adversely affect his or her ability to engage in such
activities.
Orthostatic Hypotension
Like other opioids, SUBOXONE sublingual tablets may
produce orthostatic hypotension in ambulatory patients.
Elevation Of Cerebrospinal Fluid Pressure
Buprenorphine, like other opioids, may elevate
cerebrospinal fluid pressure and should be used with caution in patients with
head injury, intracranial lesions, and other circumstances when cerebrospinal
pressure may be increased. Buprenorphine can produce miosis and changes in the
level of consciousness that may interfere with patient evaluation.
Elevation Of Intracholedochal Pressure
Buprenorphine has been shown to increase intracholedochal
pressure, as do other opioids, and thus should be administered with caution to
patients with dysfunction of the biliary tract.
Effects In Acute Abdominal Conditions
As with other opioids, buprenorphine may obscure the
diagnosis or clinical course of patients with acute abdominal conditions.
Patient Counseling Information
Advise patients to read the
FDA-approved patient labeling (Medication Guide)
Safe Use
Before initiating treatment
with SUBOXONE sublingual tablets, explain the points listed below to caregivers
and patients. Instruct patients to read the Medication Guide each time SUBOXONE
sublingual tablet is dispensed because new information may be available.
- SUBOXONE sublingual tablet must
be administered whole. Advise patients not to cut, chew, or swallow SUBOXONE
sublingual tablet.
- Inform patients and caregivers
that potentially fatal additive effects may occur if SUBOXONE sublingual tablets
is used with benzodiazepines or other CNS depressants, including alcohol.
Counsel patients that such medications should not be used concomitantly unless
supervised by a health care provider [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS].
- Advise patients that SUBOXONE
sublingual tablets contain an opioid that can be a target for people who abuse
prescription medications or street drugs, to keep their tablets in a safe
place, and to protect them from theft.
- Instruct patients to keep
SUBOXONE sublingual tablets in a secure place, out of the sight and reach of children.
Accidental or deliberate ingestion by a child may cause respiratory depression
that can result in death. Advise patients to seek medical attention immediately
if a child is exposed to SUBOXONE sublingual tablets.
- Inform patients that opioids
could cause a rare but potentially life-threatening condition resulting from concomitant
administration of serotonergic drugs. Warn patients of the symptoms of
serotonin syndrome and to seek medical attention right away if symptoms
develop. Instruct patients to inform their healthcare providers if they are
taking, or plan to take serotonergic medications [see DRUG INTERACTIONS].
- Inform patients that opioids
could cause adrenal insufficiency, a potentially life-threatening condition. Adrenal
insufficiency may present with non-specific symptoms and signs such as nausea,
vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure.
Advise patients to seek medical attention if they experience a constellation of
these symptoms [see WARNINGS AND PRECAUTIONS].
- Advise patients to never give
SUBOXONE sublingual tablets to anyone else, even if he or she has the same signs
and symptoms. It may cause harm or death.
- Advise patients that selling or
giving away this medication is against the law.
- Caution patients that SUBOXONE
sublingual tablets may impair the mental or physical abilities required for the
performance of potentially dangerous tasks such as driving or operating
machinery. Caution should be taken especially during drug induction and dose
adjustment and until individuals are reasonably certain that buprenorphine
therapy does not adversely affect their ability to engage in such activities [see WARNINGS AND PRECAUTIONS].
- Advise patients not to change
the dosage of SUBOXONE sublingual tablets without consulting their healthcare
provider.
- Advise patients that if they
miss a dose of SUBOXONE sublingual tablet they should take it as soon as they remember.
If it is almost time for the next dose, they should skip the missed dose and
take the next dose at the regular time.
- Advise patients to take
SUBOXONE sublingual tablets once a day.
- Inform patients that SUBOXONE
sublingual tablets can cause drug dependence and that withdrawal signs and
symptoms may occur when the medication is discontinued.
- Advise patients seeking to
discontinue treatment with buprenorphine for opioid dependence to work closely
with their healthcare provider on a tapering schedule and inform them of the
potential to relapse to illicit drug use associated with discontinuation of
opioid agonist/partial agonist medication-assisted treatment.
- Advise patients that, like
other opioids, SUBOXONE sublingual tablets may produce orthostatic hypotension in
ambulatory individuals [see WARNINGS AND PRECAUTIONS].
- Advise patients to inform their
healthcare provider if any other prescription medications, over-the-counter medications,
or herbal preparations are prescribed or currently being used [see DRUG
INTERACTIONS].
- Advise women that if they are
pregnant while being treated with SUBOXONE sublingual tablet, the baby may have
signs of withdrawal at birth and that withdrawal is treatable [see WARNINGS
AND PRECAUTIONS, Use In Specific Populations].
- Advise women who are
breastfeeding to monitor the infant for drowsiness and difficulty breathing [see Use In Specific Populations].
- Inform patients that chronic
use of opioids may cause reduced fertility. It is not known whether these effects
on fertility are reversible [see Use In Specific Populations].
- Advise patients to inform their
family members that, in the event of emergency, the treating healthcare provider
or emergency room staff should be informed that the patient is physically
dependent on an opioid and that the patient is being treated with SUBOXONE
sublingual tablets.
Disposal Of Unused SUBOXONE
Sublingual Tablets
Unused SUBOXONE sublingual
tablets should be disposed of as soon as they are no longer needed. Unused tablets
should be flushed down the toilet.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis,
Impairment Of Fertility
Carcinogenicity
A carcinogenicity study of
buprenorphine/naloxone (4:1 ratio of the free bases) was performed in Alderley
Park rats. Buprenorphine/naloxone was administered in the diet at doses of
approximately 7, 31, and 123 mg/kg/day for 104 weeks (estimated exposure was
approximately 4, 18, and 44 times the recommended human sublingual dose of 16/4
mg buprenorphine/naloxone based on buprenorphine AUC comparisons). A statistically
significant increase in Leydig cell adenomas was observed in all dose groups.
No other drug-related tumors were noted.
Carcinogenicity studies of
buprenorphine were conducted in Sprague-Dawley rats and CD-1 mice. Buprenorphine
was administered in the diet to rats at doses of 0.6, 5.5, and 56 mg/kg/day
(estimated exposure was approximately 0.4, 3, and 35 times the recommended
human daily sublingual dose of 16 mg on a mg/m² basis) for 27 months. As in the
buprenorphine/naloxone carcinogenicity study in rat, statistically significant dose-related
increases in Leydig cell tumors occurred. In an 86-week study in CD-1 mice,
buprenorphine was not carcinogenic at dietary doses up to 100 mg/kg/day
(estimated exposure was approximately 30 times the recommended human daily
sublingual dose of 16 mg on a mg/m² basis).
Mutagenicity
The 4:1 combination of
buprenorphine and naloxone was not mutagenic in a bacterial mutation assay
(Ames test) using four strains of S. typhimurium and two strains of E.
coli. The combination was not clastogenic in an in vitro cytogenetic assay
in human lymphocytes or in an IV micronucleus test in the rat.
Buprenorphine was studied in a
series of tests utilizing gene, chromosome, and DNA interactions in both prokaryotic
and eukaryotic systems. Results were negative in yeast (S. cerevisiae) for
recombinant, gene convertant, or forward mutations; negative in Bacillus
subtilis “rec” assay, negative for clastogenicity in CHO cells, Chinese
hamster bone marrow and spermatogonia cells, and negative in the mouse lymphoma
L5178Y assay.
Results were equivocal in the
Ames test: negative in studies in two laboratories, but positive for frame
shift mutation at a high dose (5 mg/plate) in a third study. Results were
positive in the Green-Tweets (E. coli) survival test, positive in a DNA
synthesis inhibition test with testicular tissue from mice, for both in vivo
and in vitro incorporation of [3H]thymidine, and positive in unscheduled DNA
synthesis test using testicular cells from mice.
Impairment Of Fertility
Dietary administration of
buprenorphine in the rat at dose levels of 500 ppm or greater (equivalent to approximately
47 mg/kg/day or greater; estimated exposure approximately 28 times the
recommended human daily sublingual dose of 16 mg on a mg/m² basis) produced a
reduction in fertility demonstrated by reduced female conception rates. A
dietary dose of 100 ppm (equivalent to approximately 10 mg/kg/day; estimated exposure
approximately 6 times the recommended human daily sublingual dose of 16 mg on a
mg/m² basis) had no adverse effect on fertility.
Use In Specific Populations
Pregnancy
Risk Summary
The data on use of buprenorphine, one of the active
ingredients in SUBOXONE sublingual tablets, in pregnancy, are limited; however,
these data do not indicate an increased risk of major malformations
specifically due to buprenorphine exposure. There are limited data from
randomized clinical trials in women maintained on buprenorphine that were not
designed appropriately to assess the risk of major malformations [see Data].
Observational studies have reported on congenital malformations among
buprenorphine-exposed pregnancies, but were also not designed
appropriately to assess the risk of congenital malformations specifically due
to buprenorphine exposure [see Data]. The extremely limited data on
sublingual naloxone exposure in pregnancy are not sufficient to evaluate a
drug-associated risk.
Reproductive and developmental studies in rats and
rabbits identified adverse events at clinically relevant and higher doses.
Embryo-fetal death was observed in both rats and rabbits administered
buprenorphine during the period of organogenesis at doses approximately 6 and
0.3 times, respectively, the human sublingual dose of 16 mg/day of
buprenorphine. Pre- and post-natal development studies in rats demonstrated
increased neonatal deaths at 0.3 times and above and dystocia at approximately
3 times the human sublingual dose of 16 mg/day of buprenorphine. No clear
teratogenic effects were seen when buprenorphine was administered during
organogenesis with a range of doses equivalent to or greater than the human
sublingual dose of 16 mg/day of buprenorphine. However, increases in skeletal
abnormalities were noted in rats and rabbits administered buprenorphine daily
during organogenesis at doses approximately 0.6 times and approximately equal
to the human sublingual dose of 16 mg/day of buprenorphine, respectively. In a
few studies, some events such as acephalus and omphalocele were also observed
but these findings were not clearly treatmentrelated [see Data]. Based
on animal data, advice pregnant women of the potential risk to a fetus.
The estimated background risks of major birth defects and
miscarriage for the indicated population 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 2-4% and 15-20%,
respectively.
Clinical Considerations
Disease-Associated Maternal And Embryo-Fetal Risk
Untreated opioid addiction in pregnancy is associated with
adverse obstetrical outcomes such as low birth weight, preterm birth, and fetal
death. In addition, untreated opioid addiction often results in continued or relapsing
illicit opioid use.
Dose Adjustment During Pregnancy And The Postpartum
Period
Dosage adjustments of buprenorphine may be required
during pregnancy, even if the patient was maintained on a stable dose prior to
pregnancy. Withdrawal signs and symptoms should be monitored closely and the
dose adjusted as necessary.
Fetal/Neonatal Adverse Reactions
Neonatal opioid withdrawal syndrome may occur in newborn
infants of mothers who are receiving treatment with SUBOXONE sublingual
tablets.
Neonatal opioid withdrawal syndrome presents as
irritability, hyperactivity and abnormal sleep pattern, high pitched cry,
tremor, vomiting, diarrhea, and/or failure to gain weight. Signs of neonatal
withdrawal usually occur in the first days after birth. The duration and
severity of neonatal opioid withdrawal syndrome may vary. Observe newborns for
signs of neonatal opioid withdrawal syndrome and manage accordingly [see WARNINGS
AND PRECAUTIONS].
Labor Or Delivery
Opioid-dependent women on buprenorphine maintenance
therapy may require additional analgesia during labor.
Data
Human Data
Studies have been conducted to evaluate neonatal outcomes
in women exposed to buprenorphine during pregnancy. Limited data from trials,
observational studies, case series, and case reports on buprenorphine use in
pregnancy do not indicate an increased risk of major malformations specifically
due to buprenorphine. Several factors may complicate the interpretation of
investigations of the children of women who take buprenorphine during
pregnancy, including maternal use of illicit drugs, late presentation for
prenatal care, infection, poor compliance, poor nutrition, and psychosocial
circumstances. Interpretation of data is complicated further by the lack of
information on untreated opioid-dependent pregnant women, who would be
the most appropriate group for comparison. Rather, women on another form of
opioid medication-assisted treatment, or women in the general population
are generally used as the comparison group. However, women in these comparison
groups may be different from women prescribed buprenorphine-containing
products with respect to maternal factors that may lead to poor pregnancy
outcomes.
In a multicenter, double-blind, randomized,
controlled trial [Maternal Opioid Treatment: Human Experimental Research
(MOTHER)] designed primarily to assess neonatal opioid withdrawal effects,
opioid-dependent pregnant women were randomized to buprenorphine (n=86)
or methadone (n=89) treatment, with enrollment at an average gestational age of
18.7 weeks in both groups. A total of 28 of the 86 women in the buprenorphine
group (33%) and 16 of the 89 women in the methadone group (18%) discontinued
treatment before the end of pregnancy.
Among women who remained in treatment until delivery,
there was no difference between buprenorphinetreated and
methadone-treated groups in the number of neonates requiring NOWS
treatment or in the peak severity of NOWS. Buprenorphine-exposed neonates
required less morphine (mean total dose, 1.1 mg vs. 10.4 mg), had shorter
hospital stays (10.0 days vs. 17.5 days), and shorter duration of treatment for
NOWS (4.1 days vs. 9.9 days) compared to the methadone-exposed group.
There were no differences between groups in other primary outcomes (neonatal
head circumference,) or secondary outcomes (weight and length at birth, preterm
birth, gestational age at delivery, and 1-minute and 5-minute Apgar
scores), or in the rates of maternal or neonatal adverse events. The outcomes
among mothers who discontinued treatment before delivery and may have relapsed
to illicit opioid use are not known. Because of the imbalance in discontinuation
rates between the buprenorphine and methadone groups, the study findings are
difficult to interpret.
Animal Data
The exposure margins listed below are based on body
surface area comparisons (mg/m²) to the human sublingual dose of 16 mg
buprenorphine via SUBOXONE sublingual tablets.
Effects on embryo-fetal development were studied in
Sprague-Dawley rats and Russian white rabbits following oral (1:1) and
intramuscular (IM) (3:2) administration of mixtures of buprenorphine and
naloxone during the period of organogenesis. Following oral administration to
rats no teratogenic effects were observed at buprenorphine doses up to 250
mg/kg/day (estimated exposure approximately 150 times the human sublingual dose
of 16 mg) in the presence of maternal toxicity (mortality). Following oral
administration to rabbits, no teratogenic effects were observed at
buprenorphine doses up to 40 mg/kg/day (estimated exposure approximately 50
times, the human sublingual dose of 16 mg) in the absence of clear maternal
toxicity. No definitive drug-related teratogenic effects were observed in rats
and rabbits at IM doses up to 30 mg/kg/day (estimated exposure approximately 20
times and 35 times, respectively, the human sublingual dose of 16 mg). Maternal
toxicity resulting in mortality was noted in these studies in both rats and
rabbits. Acephalus was observed in one rabbit fetus from the low-dose group and
omphalocele was observed in two rabbit fetuses from the same litter in the
mid-dose group; no findings were observed in fetuses from the high-dose group. Maternal
toxicity was seen in the high-dose group but not at the lower doses where the
findings were observed. Following oral administration of buprenorphine to rats,
dose-related post-implantation losses, evidenced by increases in the numbers of
early resorptions with consequent reductions in the numbers of fetuses, were
observed at doses of 10 mg/kg/day or greater (estimated exposure approximately
6 times the human sublingual dose of 16 mg). In the rabbit, increased
post-implantation losses occurred at an oral dose of 40 mg/kg/day. Following IM
administration in the rat and the rabbit, post-implantation losses, as
evidenced by decreases in live fetuses and increases in resorptions, occurred
at 30 mg/kg/day.
Buprenorphine was not teratogenic in rats or rabbits
after IM or subcutaneous (SC) doses up to 5 mg/kg/day (estimated exposure was
approximately 3 and 6 times, respectively, the human sublingual dose of 16 mg),
after IV doses up to 0.8 mg/kg/day (estimated exposure was approximately 0.5
times and equal to, respectively, the human sublingual dose of 16 mg), or after
oral doses up to 160 mg/kg/day in rats (estimated exposure was approximately 95
times the human sublingual dose of 16 mg) and 25 mg/kg/day in rabbits
(estimated exposure was approximately 30 times the human sublingual dose of 16
mg). Significant increases in skeletal abnormalities (e.g., extra thoracic
vertebra or thoraco-lumbar ribs) were noted in rats after SC administration of
1 mg/kg/day and up (estimated exposure was approximately 0.6 times the human
sublingual dose of 16 mg), but were not observed at oral doses up to 160
mg/kg/day. Increases in skeletal abnormalities in rabbits after IM
administration of 5 mg/kg/day (estimated exposure was approximately 6 times the
human sublingual dose of 16 mg) in the absence of maternal toxicity or oral
administration of 1 mg/kg/day or greater (estimated exposure was approximately
equal to the human sublingual dose of 16 mg) were not statistically
significant.
In rabbits, buprenorphine produced statistically
significant pre-implantation losses at oral doses of 1 mg/kg/day or greater and
post-implantation losses that were statistically significant at IV doses of 0.2
mg/kg/day or greater (estimated exposure approximately 0.3 times the human
sublingual dose of 16 mg). No maternal toxicity was noted at doses causing
post-implantation loss in this study.
Dystocia was noted in pregnant rats treated
intramuscularly with buprenorphine from Gestation Day 14 through Lactation Day
21 at 5 mg/kg/day (approximately 3 times the human sublingual dose of 16 mg). Fertility,
and pre- and postnatal development studies with buprenorphine in rats indicated
increases in neonatal mortality after oral doses of 0.8 mg/kg/day and up
(approximately 0.5 times the human sublingual dose of 16 mg), after IM doses of
0.5 mg/kg/day and up (approximately 0.3 times the human sublingual dose of 16
mg), and after SC doses of 0.1 mg/kg/day and up (approximately 0.06 times the
human sublingual dose of 16 mg). An apparent lack of milk production during
these studies likely contributed to the decreased pup viability and lactation
indices. Delays in the occurrence of righting reflex and startle response were
noted in rat pups at an oral dose of 80 mg/kg/day (approximately 50 times the
human sublingual dose of 16 mg).
Lactation
Risk Summary
Based on two studies in 13 lactating women maintained on
buprenorphine treatment, buprenorphine and its metabolite norbuprenorphine were
present in low levels in human milk and available data have not shown adverse
reactions in breastfed infants. There are no data on the combination product
buprenorphine/naloxone in breastfeeding, however oral absorption of naloxone is
limited. The developmental and health benefits of breastfeeding should be
considered along with the mother's clinical need for SUBOXONE sublingual tablet
and any potential adverse effects on the breastfed child from the drug or from
the underlying maternal condition.
Clinical Considerations
Advise breastfeeding women taking buprenorphine products
to monitor the infant for increased drowsiness and breathing difficulties.
Data
Data were consistent from two studies (N=13) of
breastfeeding infants whose mothers were maintained on sublingual doses of
buprenorphine ranging from 2.4 to 24 mg/day, showing that the infants were
exposed to less than 1% of the maternal daily dose.
In a study of six lactating women who were taking a
median sublingual buprenorphine dose of 0.29 mg/kg/day 5 to 8 days after
delivery, breast milk provided a median infant dose of 0.42 mcg/kg/day of
buprenorphine and 0.33 mcg/kg/day of norbuprenorphine, equal to 0.2% and 0.12%,
respectively, of the maternal weight-adjusted dose (relative dose/kg (%)
of norbuprenorphine was calculated from the assumption that buprenorphine and norbuprenorphine
are equipotent).
Data from a study of seven lactating women who were
taking a median sublingual buprenorphine dose of 7 mg/day an average of 1.12
months after delivery indicated that the mean milk concentrations (Cavg) of buprenorphine
and norbuprenorphine were 3.65 mcg/L and 1.94 mcg/L respectively. Based on the
study data, and assuming milk consumption of 150 mL/kg/day, an exclusively
breastfed infant would receive an estimated mean absolute infant dose (AID) of
0.55 mcg/kg/day of buprenorphine and 0.29 mcg/kg/day of norbuprenorphine, or a
mean relative infant dose (RID) of 0.38% and 0.18%, respectively, of the
maternal weight-adjusted dose.
Females And Males Of Reproductive Potential
Infertility
Chronic use of opioids may cause reduced fertility in
females and males of reproductive potential. It is not known whether these
effects on fertility are reversible [see ADVERSE REACTIONS, CLINICAL
PHARMACOLOGY, Nonclinical Toxicology].
Pediatric Use
The safety and effectiveness of SUBOXONE sublingual
tablets have not been established in pediatric patients. This product is not
appropriate for the treatment of neonatal abstinence syndrome in neonates,
because it contains naloxone, an opioid antagonist.
Geriatric Use
Clinical studies of SUBOXONE sublingual tablets, SUBOXONE
sublingual film, or SUBUTEX sublingual tablets did not include sufficient
numbers of subjects aged 65 and over to determine whether they responded
differently than younger subjects. Other reported clinical experience has not
identified differences in responses between the elderly and younger patients.
Due to possible decreased hepatic, renal, or cardiac function and of concomitant
disease or other drug therapy in geriatric patients, the decision to prescribe
SUBOXONE sublingual tablet should be made cautiously in individuals 65 years of
age or older and these patients should be monitored for signs and symptoms of
toxicity or overdose.
Hepatic Impairment
The effect of hepatic impairment on the pharmacokinetics
of buprenorphine and naloxone has been evaluated in a pharmacokinetic study.
Both drugs are extensively metabolized in the liver. While no clinically
significant changes have been observed in subjects with mild hepatic
impairment; the plasma levels have been shown to be higher and half-life values
have been shown to be longer for both buprenorphine and naloxone in subjects with
moderate and severe hepatic impairment. The magnitude of the effects on
naloxone are greater than that on buprenorphine in both moderately and severely
impaired subjects. The difference in magnitude of the effects on naloxone and
buprenorphine are greater in subjects with severe hepatic impairment than in
subjects with moderate hepatic impairment, and therefore the clinical impact of
these effects is likely to be greater in patients with severe hepatic
impairment than in patients with moderate hepatic impairment. Buprenorphine/naloxone
products should be avoided in patients with severe hepatic impairment and may
not be appropriate for patients with moderate hepatic impairment [see WARNINGS
AND PRECAUTIONS, CLINICAL PHARMACOLOGY].
Renal Impairment
No differences in buprenorphine pharmacokinetics were
observed between 9 dialysis-dependent and 6 normal patients following IV
administration of 0.3 mg buprenorphine. The effects of renal failure on
naloxone pharmacokinetics are unknown.