Buprenorphine

Table 5 includes clinically significant drug interactions with SUBLOCADE. Table 5 Clinically Significant Drug Interactions Benzodiazepines and Other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effects, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, increases the risk of respiratory depression, profound sedation, coma, and death. Intervention: 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. Similarly, cessation of other CNS depressants is preferred when possible. Before co-prescribing benzodiazepines for anxiety or insomnia, ensure that patients are appropriately diagnosed and consider alternative medications and non-pharmacologic treatments [see Warnings and Precautions ( 5.4 , 5.5 )] . If concomitant use is warranted, strongly consider prescribing naloxone for the emergency treatment of opioid overdose, as is recommended for all patients in treatment for opioid use disorder [see Warnings and Precautions ( 5.4 )].

Examples: Alcohol, benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids. Inhibitors of CYP3A4 Clinical Impact: The effects of co-administered CYP3A4 inhibitors on buprenorphine exposure in subjects treated with SUBLOCADE have not been studied and the effects may be dependent on the route of administration; however, such interactions have been established in studies using transmucosal buprenorphine. Buprenorphine is metabolized to norbuprenorphine primarily by CYP3A4; therefore, potential interactions may occur when SUBLOCADE is given concurrently with agents that affect CYP3A4 activity.

The concomitant use of sublingual buprenorphine and CYP3A4 inhibitors (e.g., ketoconazole) can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects. Intervention: Patients who transfer to SUBLOCADE treatment from a regimen of transmucosal buprenorphine used concomitantly with CYP3A4 inhibitors [e.g., azole antifungals such as ketoconazole, macrolide antibiotics such as erythromycin, and HIV protease inhibitors (e.g., ritonavir, indinavir, and saquinavir)] should be monitored to ensure that the plasma buprenorphine level provided by SUBLOCADE is adequate.

If patients already on SUBLOCADE require newly-initiated treatment with CYP3A4 inhibitors, the patients should be monitored for signs and symptoms of over-medication. Within 2 weeks of SUBLOCADE administration, if signs and symptoms of buprenorphine toxicity or overdose occur but the concomitant medication cannot be reduced or discontinued, it may be necessary to remove the depot and treat the patient with a formulation of buprenorphine that permits dose adjustments. Conversely, if a patient has been stabilized on SUBLOCADE in the setting of concomitant medication that is a CYP3A4 inhibitor, and the concomitant medication is discontinued, the patient should be monitored for withdrawal.

If the dose of SUBLOCADE is not adequate in the absence of the concomitant medication, that patient should be transitioned back to a formulation of buprenorphine that permits dose adjustments. Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The effects of co-administered CYP3A4 inducers on buprenorphine exposure in subjects treated with SUBLOCADE have not been studied. Buprenorphine is metabolized to norbuprenorphine primarily by CYP3A4; therefore, potential interactions may occur when SUBLOCADE is given concurrently with agents that affect CYP3A4 activity.

CYP3A4 inducers may induce the metabolism of buprenorphine and, therefore, may cause increased clearance of the drug which could lead to a decrease in buprenorphine plasma concentrations, lack of efficacy or, possibly, development of an abstinence syndrome. Intervention: Patients who transfer to SUBLOCADE treatment from a regimen of transmucosal buprenorphine used concomitantly with CYP3A4 inducers should be monitored to ensure that the plasma buprenorphine level provided by SUBLOCADE is adequate. If patients already on SUBLOCADE require newly-initiated treatment with CYP3A4 inducers, the patients should be monitored for withdrawal.

If the dose of SUBLOCADE is not adequate in the absence of the concomitant medication, and the concomitant medication cannot be reduced or discontinued, that patient should be transitioned back to a formulation of buprenorphine that permits dose adjustments. Conversely, if a patient has been stabilized on SUBLOCADE in the setting of concomitant medication that is a CYP3A4 inducer, and the concomitant medication is discontinued, the patient should be monitored for signs and symptoms of over-medication.

Within 2 weeks of SUBLOCADE administration, if the dose provided by SUBLOCADE is excessive in the absence of the concomitant inducer, it may be necessary to remove the SUBLOCADE and treat the patient with a formulation of buprenorphine that permits dose adjustments [see Clinical Pharmacology ( 12.3 )] . Examples: Rifampin, carbamazepine, phenytoin, phenobarbital Antiretrovirals: Non-nucleoside reverse transcriptase inhibitors (NNRTIs) Clinical Impact: Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are metabolized principally by CYP3A4. Efavirenz, nevirapine, and etravirine are known CYP3A inducers, whereas delavirdine is a CYP3A inhibitor.

Significant pharmacokinetic interactions between NNRTIs (e.g., efavirenz and delavirdine) and sublingual buprenorphine have been shown in clinical studies, but these pharmacokinetic interactions did not result in any significant pharmacodynamic effects. Intervention: Patients who are on chronic treatment with SUBLOCADE should be monitored for increase or decrease in therapeutic effects if NNRTIs are added to their treatment regimen.

Examples: Efavirenz, nevirapine, etravirine, delavirdine Antiretrovirals: Protease inhibitors (PIs) Clinical Impact: Studies have shown some antiretroviral protease inhibitors (PIs) with CYP3A4 inhibitory activity (nelfinavir, lopinavir/ritonavir, ritonavir) have little effect on sublingual buprenorphine pharmacokinetic and no significant pharmacodynamic effects. Other PIs with CYP3A4 inhibitory activity (atazanavir and atazanavir/ritonavir) resulted in elevated levels of buprenorphine and norbuprenorphine after sublingual administration, and patients in one study reported increased sedation.

Symptoms of opioid excess have been found in postmarketing reports of patients receiving sublingual buprenorphine and atazanavir with and without ritonavir concomitantly. Intervention: If treatment with atazanavir with and without ritonavir must be initiated in a patient already treated with SUBLOCADE, the patient should be monitored for signs and symptoms of over-medication. It may be necessary to remove the depot and treat the patient with a sublingual buprenorphine product that permits rapid dose adjustments.

Examples: Atazanavir, ritonavir Antiretrovirals: Nucleoside reverse transcriptase inhibitors (NRTIs) Clinical Impact: Nucleoside reverse transcriptase inhibitors (NRTIs) do not appear to induce or inhibit the P450 enzyme pathway, thus no interactions with buprenorphine are expected. Intervention: None Serotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Intervention: If concomitant use is warranted, carefully monitor the patient for signs and symptoms of serotonin syndrome, particularly during treatment initiation, and during dose adjustment of the serotonergic drug.

Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (e.g., respiratory depression, coma).

Intervention: The use of SUBLOCADE is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. Examples: Phenelzine, tranylcypromine, linezolid Muscle Relaxants Clinical Impact: Buprenorphine may enhance the neuromuscular blocking action of skeletal…

8.1 Pregnancy Risk Summary The data on use of buprenorphine, the active ingredient in SUBLOCADE, 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 Human Data ] . Observational studies have reported 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 Human Data ] .

In animal reproduction studies with SUBLOCADE, SUBLOCADE administered subcutaneously to pregnant rats and rabbits during the period of organogenesis at a buprenorphine dose equivalent to 38 and 15 times, respectively, the maximum recommended human dose (MRHD) of 300 mg caused embryolethality, which appeared to be attributable primarily to the SUBLOCADE vehicle (ATRIGEL ® delivery system). In addition, reduced fetal body weights, increased visceral malformations and skeletal malformations were observed in rats and rabbits at buprenorphine doses equivalent to 38 and 15 times, respectively, the MRHD.

These effects were also observed with the ATRIGEL ® delivery system alone, but the skeletal and visceral malformations in rat appear at least partially attributable to buprenorphine [see Animal 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 is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

SUBLOCADE should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. 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. Fetal/neonatal adverse reactions Neonatal opioid withdrawal syndrome may occur in newborn infants of mothers who are receiving treatment with SUBLOCADE. Neonatal opioid withdrawal syndrome presents as…