WARNINGS
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS
Addiction, Abuse And Misuse
ZUBSOLV 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 Depression 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 ZUBSOLV [see Managing Risks From Concomitant Use Of Benzodiazepines Or Other CNS Depressants, DRUG INTERACTIONS].
Use ZUBSOLV with caution in patients with compromised respiratory function (e.g., chronic obstructive pulmonary disease, cor pulmonale, decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing 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 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 ZUBSOLV 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. When discontinuing ZUBSOLV, 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, ZUBSOLV 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 ZUBSOLV.
Precipitation Of Opioid Withdrawal Signs And Symptoms
Because it contains naloxone, ZUBSOLV 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, ZUBSOLV 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 naive individuals who received a 2 mg dose of buprenorphine as a sublingual tablet for analgesia. ZUBSOLV 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. 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
ZUBSOLV 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 ZUBSOLV therapy does not adversely affect his or her ability to engage in such activities.
Orthostatic Hypotension
Like other opioids, ZUBSOLV 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 ZUBSOLV, explain the points listed below to caregivers and patients. Instruct patients to read the Medication Guide each time ZUBSOLV is dispensed because new information may be available.
- ZUBSOLV must be administered whole. Advise patients not to cut, chew, or swallow ZUBSOLV.
- Inform patients and caregivers that potentially fatal additive effects may occur if ZUBSOLV 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 ZUBSOLV 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 ZUBSOLV 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 ZUBSOLV.
- 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 ZUBSOLV 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 ZUBSOLV 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 ZUBSOLV without consulting their healthcare provider.
- Advise patients to take ZUBSOLV once a day, after induction.
- Advise patients that if they miss a dose of ZUBSOLV 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 ZUBSOLV 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 should be advised 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, ZUBSOLV 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 ZUBSOLV, 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 ADVERSE REACTIONS].
- 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 ZUBSOLV.
Disposal Of Unused ZUBSOLV Sublingual Tablets
Unused ZUBSOLV 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
ZUBSOLV has been shown to have differences in bioavailability compared to other buprenorphine/naloxone-containing sublingual products. The exposure margins listed below are based on body surface area comparisons (mg/m2) to the recommended human sublingual dose of 16 mg buprenorphine via Suboxone, which is equivalent to a human sublingual dose of 11.4 mg buprenorphine via ZUBSOLV.
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 mg/kg/day, 31 mg/kg/day, and 123 mg/kg/day for 104 weeks (estimated exposure was approximately 4, 18, and 44 times the recommended human sublingual dose 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 mg/kg/day, 5.5 mg/kg/day, and 56 mg/kg/day (estimated exposure was approximately 0.4, 3, and 35 times the recommended human sublingual dose) 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 sublingual dose).
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 sublingual dose) 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 sublingual dose) 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 ZUBSOLV, 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 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 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, advice 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. 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 ZUBSOLV.
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
ZUBSOLV has been shown to have differences in bioavailability compared to other buprenorphine/naloxone-containing sublingual products. 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, which is equivalent to a
human sublingual dose of 11.4 mg buprenorphine via ZUBSOLV.
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 daily 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 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 ZUBSOLV and any potential adverse effects on the breastfed child from the drug or from the underlying maternal condition.
Clinical Considerations
Advise the 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, Nonclinical Toxicology].
Pediatric Use
The safety and effectiveness of ZUBSOLV have not been established in pediatric patients. This product is not appropriate for the treatment of neonatal opioid withdrawal syndrome in neonates, because it contains naloxone, an opioid antagonist.
Geriatric Use
Clinical studies of buprenorphine/naloxone 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 have 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 ZUBSOLV
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 is 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 [see CLINICAL PHARMACOLOGY].