Nalbuphine Hydrochloride

Nalbuphine Hydrochloride Injection is indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Nalbuphine Hydrochloride Injection can also be used as a supplement to balanced anesthesia, for preoperative and postoperative analgesia, and for obstetrical analgesia during labor and delivery. Limitations of Use: Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy [see WARNINGS ], reserve opioid analgesics, including Nalbuphine Hydrochloride Injection, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.

Nalbuphine Hydrochloride Injection is contraindicated in patients with:

• Significant respiratory depression [see WARNINGS ]
• Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see WARNINGS ]
• Known or suspected gastrointestinal obstruction, including paralytic ileus [see WARNINGS ]
• Hypersensitivity to nalbuphine or any of the other ingredients in Nalbuphine Hydrochloride Injection.

Addiction, Abuse, and Misuse Nalbuphine Hydrochloride Injection contains nalbuphine. As an opioid, nalbuphine exposes users to the risks of addiction, abuse, and misuse [see DRUG ABUSE AND DEPENDENCE ]. The risk of opioid‑related overdose or overdose-related death is increased with higher opioid doses, and this risk persists over the course of therapy. In postmarketing studies, addiction, abuse, misuse, and fatal and non-fatal opioid overdose were observed in patients with long-term opioid use [see ADVERSE REACTIONS ]. Opioids are sought for non-medical use and are subject to diversion from legitimate prescribed use. Consider these risks when handling Nalbuphine Hydrochloride Injection. Strategies to reduce these risks include proper product storage and control practices for a C-II drug. Contact local state professional licensing board or state-controlled substances authority for information on how to prevent and detect abuse or diversion of this product. Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, even when used as recommended. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression may include close observation, supportive measures, and use of opioid overdose reversal agents (e.g., naloxone, nalmefene), depending on the patient's clinical status [see OVERDOSAGE ]. Carbon dioxide (CO 2 ) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of Nalbuphine Hydrochloride Injection, the risk is greatest during the initiation of therapy or following a dosage increase. Monitor patients closely for respiratory depression, especially within the first 24 to 72 hours of initiating therapy with and following dosage increases of Nalbuphine Hydrochloride Injection. To reduce the risk of respiratory depression, proper dosing and titration of Nalbuphine Hydrochloride Injection are essential [see DOSAGE AND ADMINISTRATION ]. Overestimating the Nalbuphine Hydrochloride Injection dosage when converting patients from another opioid product can result in a fatal overdose with the first dose. Opioids can cause sleep-related breathing disorders including central sleep apnea (CSA) and sleep-related hypoxemia. Opioid use increases the risk of CSA in a dose-dependent fashion. In patients who present with CSA, consider decreasing the opioid dosage using best practices for opioid taper [see DOSAGE AND ADMINISTRATION ]. Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Profound sedation, respiratory depression, coma, and death may result from the concomitant use of Nalbuphine Hydrochloride Injection with benzodiazepines and/or other CNS depressants, including alcohol (e.g., non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids [gabapentin or pregabalin], and other opioids). Because of these risks, reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Monitor patients closely for signs and symptoms of respiratory depression and sedation. Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioid analgesics alone. Because of similar pharmacological properties, it is reasonable to expect similar risk with the concomitant use of other CNS depressant drugs with opioid analgesics [see PRECAUTIONS; Drug Interactions ]. If the decision is made to prescribe a benzodiazepine or other CNS depressant concomitantly with an opioid analgesic, prescribe the lowest effective dosages and minimum durations of concomitant use. In patients already receiving an opioid analgesic, prescribe a lower initial dose of the benzodiazepine or other CNS depressant than indicated in the absence of an opioid, and titrate based on clinical response. If an opioid analgesic is initiated in a patient already taking a benzodiazepine or other CNS depressant, prescribe a lower initial dose of the opioid analgesic, and titrate based on clinical response. Follow patients closely for signs and symptoms of respiratory depression and sedation. Advise both patients and caregivers about the risks of respiratory depression and sedation when Nalbuphine Hydrochloride Injection is used with benzodiazepines or other CNS depressants (including alcohol and illicit drugs). Advise patients not to drive or operate heavy machinery until the effects of concomitant use of the benzodiazepine or other CNS depressant have been determined. Screen patients for risk of substance use disorders, including opioid abuse and misuse, and warn them of the risk for overdose and death associated with the use of additional CNS depressants including alcohol and illicit drugs [see PRECAUTIONS; Drug Interactions and Information for Patients ]. Opioid-Induced Hyperalgesia and Allodynia Opioid-Induced Hyperalgesia (OIH) occurs when an opioid analgesic ‎paradoxically causes an increase in pain, or an increase in sensitivity to ‎pain. This condition differs from tolerance, which is the need for ‎increasing doses of opioids to maintain a defined effect [see DRUG ABUSE AND DEPENDENCE; Dependence ]. ‎Symptoms of OIH include (but may not be limited to) increased levels of ‎pain upon opioid dosage increase, decreased levels of pain upon opioid ‎dosage decrease, or pain from ordinarily non-painful stimuli (allodynia). ‎These symptoms may suggest OIH only if there is no evidence of ‎underlying disease progression, opioid tolerance, opioid withdrawal, or addictive ‎behavior.‎ Cases of OIH have been reported, both with short-term and longer-term ‎use of opioid analgesics. Though the mechanism of OIH is not fully ‎understood, multiple biochemical pathways have been implicated. Medical ‎literature suggests a strong biologic plausibility between opioid ‎analgesics and OIH and allodynia. If a patient is suspected to be ‎experiencing OIH, carefully consider appropriately decreasing the dose of ‎the current opioid analgesic or opioid rotation (safely switching the ‎patient to a different opioid moiety) [see DOSAGE AND ADMINISTRATION , ‎ WARNINGS ].‎ Life-Threatening Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients The use of Nalbuphine Hydrochloride Injection in patients with acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment is contraindicated. Patients with Chronic Pulmonary Disease: Nalbuphine Hydrochloride Injection-treated patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing respiratory depression are at increased risk of decreased respiratory drive including apnea, even at recommended dosages of use of Nalbuphine Hydrochloride Injection [see WARNINGS ]. Elderly, Cachectic, or Debilitated Patients: Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients because they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients [see WARNINGS ]. Monitor such patients closely, particularly when initiating and titrating Nalbuphine Hydrochloride Injection and when Nalbuphine Hydrochloride Injection is given concomitantly with other drugs that depress respiration [see WARNINGS ]. Alternatively, consider the use of non-opioid analgesics in these patients. Adrenal Insufficiency Cases of adrenal insufficiency have been reported with opioid use, more often following greater than 1 month of use. […]

General Impaired Renal or Hepatic Function Because nalbuphine is metabolized in the liver and excreted by the kidneys, Nalbuphine Hydrochloride Injection should be used with caution in patients with renal or liver dysfunction and administered in reduced amounts. Myocardial Infarction As with all potent analgesics, Nalbuphine Hydrochloride Injection should be used with caution in patients with myocardial infarction who have nausea or vomiting. Cardiovascular System During evaluation of Nalbuphine Hydrochloride Injection in anesthesia, a higher incidence of bradycardia has been reported in patients who did not receive atropine pre-operatively. Laboratory Tests Nalbuphine Hydrochloride Injection may interfere with enzymatic methods for the detection of opioids depending on the specificity/sensitivity of the test. Consult the test manufacturer for specific details. Information for Patients Patients should be advised of the following information: Addiction, Abuse, and Misuse Inform patients that the use of Nalbuphine Hydrochloride Injection, even when ‎taken as recommended, can result in addiction, abuse, and misuse, which can lead to ‎overdose and death [see WARNINGS ].‎ Instruct patients not to share Nalbuphine Hydrochloride Injection with others and to take steps to protect ‎Nalbuphine Hydrochloride Injection from theft or misuse.‎ Life-Threatening Respiratory Depression Inform patients of the risk of life-threatening ‎respiratory depression, including information that the risk is greatest when starting ‎‎Nalbuphine Hydrochloride Injection or when the dosage is increased, and that it can occur even at recommended ‎dosages.‎ Hyperalgesia and Allodynia Inform patients and caregivers not to increase opioid dosage without first consulting a clinician. Advise patients to inform their healthcare provider if they ‎experience symptoms of hyperalgesia, including worsening pain, increased ‎sensitivity to pain, or new pain [see WARNINGS , ADVERSE REACTIONS ].‎ Serotonin Syndrome 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 after discharge from the hospital‎. Instruct patients to inform their physicians if they are taking, or plan to take serotonergic medications [see PRECAUTIONS; Drug Interactions ]. Monoamine Oxidase Inhibitor (MAOI) Interaction Inform patients to avoid taking Nalbuphine Hydrochloride Injection while using any drugs that inhibit monoamine oxidase. Patients should not start MAOIs while taking Nalbuphine Hydrochloride Injection [see PRECAUTIONS; Drug Interactions ]. Constipation Advise patients of the potential for severe constipation, including management instructions and when to seek medical attention [see ADVERSE REACTIONS , CLINICAL PHARMACOLOGY ]. Drug Interactions Benzodiazepines and other Central Nervous System (CNS) Depressants Although Nalbuphine Hydrochloride Injection possesses opioid antagonist activity, there is evidence that in nondependent patients it will not antagonize an opioid analgesic administered just before, concurrently, or just after an injection of Nalbuphine Hydrochloride Injection. Therefore, due to additive pharmacologic effects, the concomitant use of other opioid analgesics, benzodiazepines or other CNS depressants such as alcohol, non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids (gabapentin or pregabalin), and other opioids, can increase the risk of respiratory depression, profound sedation, coma, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation [see WARNINGS ]. Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system, such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that effect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), and monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue), has resulted in serotonin syndrome [see PRECAUTIONS; Information for Patients ]. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue Nalbuphine Hydrochloride Injection if serotonin syndrome is suspected. Monoamine Oxidase Inhibitors (MAOIs) MAOI (e.g., phenelzine, tranylcypromine, linezolid) interactions with opioids may manifest as serotonin syndrome [see PRECAUTIONS; Drug Interactions ] or opioid toxicity (e.g., respiratory depression, coma [see WARNINGS ]). The use of Nalbuphine Hydrochloride Injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. Muscle Relaxants Nalbuphine may enhance the neuromuscular blocking action of skeletal muscle relaxants (e.g., cyclobenzaprine, metaxalone) and produce an increased degree of respiratory depression. Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of Nalbuphine Hydrochloride Injection and/or the muscle relaxant as necessary. Diuretics Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. Anticholinergic Drugs The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor patients for signs of urinary retention or reduced gastric motility when Nalbuphine Hydrochloride Injection is used concomitantly with anticholinergic drugs. Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis There was no evidence of carcinogenicity in long term animal studies were performed in rats (24 months) and mice (19 months) by oral administration at doses up to 200 mg/kg [12 times the maximum recommended human daily dose (MRHD)] and 200 mg/ per day (6 times the MRDH), respectively. Mutagenesis Nalbuphine Hydrochloride Injection induced an increased frequency of mutation in the mouse lymphoma assay. Nalbuphine Hydrochloride Injection did not have mutagenic activity in the Ames test with four bacterial strains, in the Chinese Hamster Ovary HGPRT assays or in the Sister Chromatid Exchange Assay. Clastogenic activity was not observed in the mouse micronucleus test or the cytogenicity bone marrow assay in rats. Impairment of Fertility Female rats were treated with nalbuphine hydrochloride beginning 15 days prior to mating through Lactation Day 20 via subcutaneous doses of 14, 28, or 56 mg/kg/day (0.85, 1.7, or 3.4 times the MRHD of 160 mg/day based on body surface area, respectively). Male rats were treated via oral gavage with the same nalbuphine hydrochloride doses beginning 60 days prior to and throughout mating. There were no adverse effects on either male or female fertility. Pregnancy Risk Summary Use of opioid analgesics‎ for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome. […]

The most frequent adverse reaction in 1066 patients treated in clinical studies with Nalbuphine Hydrochloride Injection was sedation 381 (36%). Less frequent reactions were: sweaty/clammy 99 (9%), nausea/vomiting 68 (6%), dizziness/vertigo 58 (5%), dry mouth 44 (4%), and headache 27 (3%). Other adverse reactions which occurred (reported incidence of 1% or less) were: CNS Effects: Nervousness, depression, restlessness, crying, euphoria, floating, hostility, unusual dreams, confusion, faintness, hallucinations, dysphoria, feeling of heaviness, numbness, tingling, unreality. The incidence of psychotomimetic effects, such as unreality, depersonalization, delusions, dysphoria and hallucinations has been shown to be less than that which occurs with pentazocine. Cardiovascular: Hypertension, hypotension, bradycardia, tachycardia. Gastrointestinal: Cramps, dyspepsia, bitter taste. Respiratory: Depression, dyspnea, asthma. Dermatologic: Itching, burning, urticaria. Miscellaneous: Speech difficulty, urinary urgency, blurred vision, flushing and warmth. Allergic Reactions: Anaphylactic/anaphylactoid and other serious hypersensitivity reactions have been reported following the use of nalbuphine and may require immediate, supportive medical treatment. These reactions may include shock, respiratory distress, respiratory arrest, bradycardia, cardiac arrest, hypotension, or laryngeal edema. Some of these allergic reactions may be life-threatening. Other allergic-type reactions reported include stridor, bronchospasm, wheezing, edema, rash, pruritus, nausea, vomiting, diaphoresis, weakness, and shakiness. Postmarketing Experience The following adverse reactions have been identified during post approval use of nalbuphine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Abdominal pain, pyrexia, depressed level or loss of consciousness, somnolence, tremor, anxiety, pulmonary edema, agitation, seizures, and injection site reactions such as pain, swelling, redness, burning, and hot sensations. Death has been reported from severe allergic reactions to Nalbuphine Hydrochloride Injection treatment. Fetal death has been reported where mothers received Nalbuphine Hydrochloride Injection during labor and delivery. Serotonin Syndrome : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Adrenal Insufficiency : Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been ‎reported with opioid therapy of any duration [see WARNINGS ]‎. Hypoglycemia : Cases of hypoglycemia have been reported in patients ‎taking opioids. Most reports were in patients with at least one ‎predisposing risk factor (e.g., diabetes). Opioid-Induced Esophageal Dysfunction (OIED) : Cases of OIED have been reported in patients taking opioids and may occur more frequently in patients taking higher doses of opioids, and/or in patients taking opioids longer term [see WARNINGS ]. Adverse Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021. Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90‑day period (n=978); or 2) filled any Schedule II opioid analgesic prescriptions covering at least 70 of 90 days (n=1,244). Those included also had no dispensing of the qualifying opioids in the previous 6 months. Over 12 months:

• approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interview-based measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, and
• approximately 9% and 22% of participants across the two cohorts newly met criteria for prescription opioid abuse and misuse [defined in DRUG ABUSE AND DEPENDENCE ], respectively, as measured with a validated self-reported instrument. A retrospective, observational cohort study estimated the risk of opioid-involved overdose or opioid overdose-related death in patients with new long-term use of Schedule II opioid analgesics from 2006 through 2016 (n=220,249). Included patients had been enrolled in either one of two commercial insurance programs, one managed care program, or one Medicaid program for at least 9 months. New long-term use was defined as having Schedule II opioid analgesic prescriptions covering at least 70 days’ supply over the 3 months prior to study entry and none during the preceding 6 months. Patients were excluded if they had an opioid-involved overdose in the 9 months prior to study entry. Overdose was measured using a validated medical code-based algorithm with linkage to the National Death Index database. The 5-year cumulative incidence estimates for opioid-involved overdose or opioid overdose-related death ranged from approximately 1.5% to 4% across study sites, counting only the first event during follow-up. Approximately 17% of first opioid overdoses observed over the entire study period (5-11 years, depending on the study site) were fatal. Higher baseline opioid dose was the strongest and most consistent predictor of opioid-involved overdose or opioid overdose-related death. Study exclusion criteria may have selected patients at lower risk of overdose, and substantial loss to follow-up (approximately 80%) also may have biased estimates. The risk estimates from the studies described above may not be generalizable to all patients receiving opioid analgesics, such as those with exposures shorter or longer than the duration evaluated in the studies.‎

Benzodiazepines and other Central Nervous System (CNS) Depressants Although Nalbuphine Hydrochloride Injection possesses opioid antagonist activity, there is evidence that in nondependent patients it will not antagonize an opioid analgesic administered just before, concurrently, or just after an injection of Nalbuphine Hydrochloride Injection. Therefore, due to additive pharmacologic effects, the concomitant use of other opioid analgesics, benzodiazepines or other CNS depressants such as alcohol, non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids (gabapentin or pregabalin), and other opioids, can increase the risk of respiratory depression, profound sedation, coma, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation [see WARNINGS ]. Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system, such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that effect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), and monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue), has resulted in serotonin syndrome [see PRECAUTIONS; Information for Patients ]. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue Nalbuphine Hydrochloride Injection if serotonin syndrome is suspected. Monoamine Oxidase Inhibitors (MAOIs) MAOI (e.g., phenelzine, tranylcypromine, linezolid) interactions with opioids may manifest as serotonin syndrome [see PRECAUTIONS; Drug Interactions ] or opioid toxicity (e.g., respiratory depression, coma [see WARNINGS ]). The use of Nalbuphine Hydrochloride Injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. Muscle Relaxants Nalbuphine may enhance the neuromuscular blocking action of skeletal muscle relaxants (e.g., cyclobenzaprine, metaxalone) and produce an increased degree of respiratory depression. Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of Nalbuphine Hydrochloride Injection and/or the muscle relaxant as necessary. Diuretics Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. Anticholinergic Drugs The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor patients for signs of urinary retention or reduced gastric motility when Nalbuphine Hydrochloride Injection is used concomitantly with anticholinergic drugs.

Risk Summary Use of opioid analgesics‎ for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome. Available data with Nalbuphine Hydrochloride Injection in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage. In animal reproduction studies, nalbuphine decreased pup survival and pup body weights when pregnant female rats were treated late in gestation and throughout lactation at 1.7 times the MRHD and when female and male rats treated either prior to mating and throughout gestation and lactation. No malformations were observed in either rats or rabbits at doses 6.1 and 3.9 times the MRHD, respectively [see Data ] . 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. Clinical Considerations Fetal/Neonatal Adverse Reactions Severe fetal bradycardia has been reported when nalbuphine hydrochloride is administered during labor. Naloxone may reverse these effects. Although there are no reports of fetal bradycardia earlier in pregnancy, it is possible that this may occur. This drug should be used in pregnancy only if clearly needed, if the potential benefit outweighs the risk to the fetus, and if appropriate measures such as fetal monitoring are taken to detect and manage any potential adverse effect on the fetus. Labor and Delivery The placental transfer of nalbuphine is high, rapid, and variable with a maternal to fetal ratio ranging from 1:0.37 to 1:6. Fetal and neonatal adverse effects that have been reported following the administration of nalbuphine to the mother during labor include fetal bradycardia, respiratory depression at birth, apnea, cyanosis, and hypotonia. Some of these events have been life-threatening. Maternal administration of naloxone during labor has normalized these effects in some cases. Severe and prolonged fetal bradycardia has been reported. Permanent neurological damage attributed to fetal bradycardia has occurred. A sinusoidal fetal heart rate pattern associated with the use of nalbuphine has also been reported. Nalbuphine Hydrochloride Injection should be used during labor and delivery only if clearly indicated and only if the potential benefit outweighs the risk to the infant. Newborns should be monitored for respiratory depression, apnea, bradycardia and arrhythmias if Nalbuphine Hydrochloride Injection has been used. Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid overdose reversal agent, such as naloxone or nalmefene, must be available for reversal of opioid-induced respiratory depression in the neonate. Nalbuphine Hydrochloride Injection is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including Nalbuphine Hydrochloride Injection, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Animal Data Pregnant rats were treated with nalbuphine hydrochloride from Gestation Day 6 to 15 via subcutaneous doses of 7, 14, or 100 mg/kg/day (0.4, 0.85, or 6.1 times the MRHD of 160 mg/day based on body surface area, respectively). There was no evidence of malformations or embryotoxicity despite reductions in maternal weight gain in the mid- and high-dose groups. Pregnant rabbits were treated with nalbuphine hydrochloride from Gestation Day 7 to 19 via intravenous doses of 4, 8, or 32 mg/kg/day (0.5, 1, or 3.9 times the MRHD based on body surface area, respectively). There was no evidence of malformations or embryotoxicity despite reductions in maternal weight gain in the high-dose group. Pregnant rats were treated with nalbuphine hydrochloride from Gestation Day 15 to Lactation Day 20 via subcutaneous doses of 14, 28, or 56 mg/kg/day (0.85, 1.7, or 3.4 times the MRHD based on body surface area, respectively). Pup survival was decreased in the mid- and high-dose groups and neonatal body weights were dose dependently reduced. Maternal toxicity was noted in all treatment groups (reduced body weights). Female rats were treated with nalbuphine hydrochloride beginning 15 days prior to mating through Lactation Day 20 via subcutaneous doses of 14, 28, or 56 mg/kg/day (0.85, 1.7, or 3.4 times the MRHD of 160 mg/day based on body surface area, respectively). Male rats were treated via oral gavage with the same oxymorphone hydrochloride doses beginning 60 days prior to and throughout mating. There was reduced pup survival in the high dose group animals and reduced pup body weights in the mid- and high-dose groups. Lactation Limited data suggest that Nalbuphine Hydrochloride Injection is excreted in maternal milk but only in a small amount (less than 1% of the administered dose) and with a clinically insignificant effect. Infants exposed to Nalbuphine Hydrochloride Injection through breast milk should be monitored for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped.

Safety and effectiveness in pediatric patients below the age of 18 years have not been established.

Elderly patients (aged 65 years or older) may have increased sensitivity to Nalbuphine Hydrochloride Injection. In general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. Respiratory depression is the chief risk for elderly patients treated with opioids and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of Nalbuphine Hydrochloride Injection slowly in geriatric patients and frequently reevaluate the patient for signs of central nervous system ‎and respiratory depression [see WARNINGS ]. Nalbuphine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Nalbuphine is an agonist at kappa opioid receptors and an antagonist at mu opioid receptors.