WARNINGS
Included as part of the PRECAUTIONS section.
PRECAUTIONS
Addiction, Abuse, And Misuse
CASSIPA contains 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 depressants,
including alcohol. Warn patients of the potential danger of self-administration
of benzodiazepines or other CNS depressants while under treatment with CASSIPA [see
Managing Risks from Concomitant Use of Benzodiazepines or Other
CNS Depressants, DRUG INTERACTIONS]. Use CASSIPA
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 Benzodiazepines 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. Advise
patients to store buprenorphine-containing
medications safely out of the sight and reach of children and to 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 CASSIPA 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
buprenorphine, 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, are 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, CASSIPA 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 [see CLINICAL PHARMACOLOGY].
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 CASSIPA.
Precipitation Of Opioid Withdrawal Signs And Symptoms
Because it contains naloxone, CASSIPA is likely to
produce withdrawal signs and symptoms if misused parenterally by individuals
dependent on full opioid agonists such as heroin, morphine, or methadone.
Because of the partial agonist properties of buprenorphine, CASSIPA may precipitate
opioid withdrawal signs and symptoms in such persons if administered 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. CASSIPA is not appropriate as an analgesic and cannot be used in
opioid-naïve patients.
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. Because hepatic impairment results in a
reduced clearance of naloxone to a much greater extent than buprenorphine, the
doses of buprenorphine and naloxone in this fixed-dose
combination product cannot be individually titrated. Therefore, patients with
severe hepatic impairment will be exposed to substantially higher levels of
naloxone than patients with normal hepatic function. This 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. 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
CASSIPA 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 dose adjustment. Patients should
be cautioned about driving or operating hazardous machinery until they are reasonably
certain that CASSIPA therapy does not adversely affect his or her ability to
engage in such activities.
Orthostatic Hypotension
Like other opioids, CASSIPA 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 CASSIPA, explain the
points listed below to caregivers and patients. Instruct patients to read the
Medication Guide each time CASSIPA is dispensed because new information may be
available.
- CASSIPA must be administered whole. Advise patients not
to cut, chew, or swallow CASSIPA [see DOSAGE AND ADMINISTRATION].
- Inform patients and caregivers that potentially fatal
additive effects may occur if CASSIPA 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 CASSIPA contains an opioid that can
be a target for people who abuse prescription medications or street drugs.
Caution patients to keep their films in a safe place, and to protect them from
theft [see WARNINGS AND PRECAUTIONS, Drug Abuse And Dependence].
- Instruct patients to keep CASSIPA 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 CASSIPA
[see WARNINGS AND PRECAUTIONS].
- 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 lifethreatening 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 CASSIPA to anyone else,
even if he or she has the same signs and symptoms. It may cause harm or death [see WARNINGS AND PRECAUTIONS.]
- Advise patients that selling or giving away this
medication is against the law [see Drug Abuse And Dependence].
- Caution patients that CASSIPA 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 CASSIPA
without consulting their healthcare provider.
- Advise patients to take CASSIPA once a day [see DOSAGE
AND ADMINISTRATION].
- Advise patients that if they miss a dose of CASSIPA 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.
- Inform patients that CASSIPA can cause drug dependence
and that withdrawal signs and symptoms may occur when the medication is
discontinued [see WARNINGS AND PRECAUTIONS].
- 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 [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS].
- Advise patients that, like other opioids, CASSIPA 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 CASSIPA, 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 CASSIPA.
Disposal Of Unused CASSIPA
Unused CASSIPA sublingual films should be disposed of as
soon as they are no longer needed. Unused films should be flushed down the
toilet.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenicity
Carcinogenicity data on CASSIPA are not available.
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 mg/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 sublingual daily dose of 16 mg on a mg/m² basis) for 27
months. As in the buprenorphine/naloxone carcinogenicity study in rats,
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 (DSI) test with testicular
tissue from mice, for both in vivo and in vitro incorporation of [3H]thymidine,
and positive in unscheduled DNA synthesis (UDS) 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 CASSIPA, 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.
Embryofetal 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 postnatal 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 treatment-related [see Data]. Based on animal
data, advise pregnant women of the potential risk to a fetus.
The estimated background risk of major birth defects and
miscarriage for the indicated population are unknown. 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. If dosage adjustments are needed, a different product
should be used as the dose of CASSIPA cannot be adjusted.
Fetal/Neonatal Adverse Reactions
Neonatal opioid withdrawal syndrome may occur in newborn
infants of mothers who are receiving treatment with CASSIPA.
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 buprenorphine-treated 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 CASSIPA.
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 postimplantation 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, pre-,
and post-natal
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 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 buprenorphine 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, and Nonclinical Toxicology].
Pediatric Use
The safety and effectiveness of CASSIPA 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 buprenorphine and naloxone sublingual
film, buprenorphine and naloxone sublingual tablets, or buprenorphine
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 CASSIPA 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 and
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.