Pentazocine and Naloxone
(pen TAZ oh seen & nal OKS one)
- Naloxone Hydrochloride and Pentazocine
- Pentazocine HCl/Naloxone HCl
- Pentazocine Hydrochloride and Naloxone Hydrochloride
- Talwin NX
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, oral: Pentazocine 50 mg and naloxone 0.5 mg
- Analgesic, Opioid
- Analgesic, Opioid Partial Agonist
Pentazocine: Agonist of kappa opiate receptors and partial agonist of mu opiate receptors in the CNS, causing inhibition of ascending pain pathways, altering the perception of and response to pain; produces analgesia, respiratory depression and sedation similar to opioids.
Naloxone: Pure opioid antagonist that competes for and displaces opioids at opioid receptor sites in CNS. Lacks pharmacologic activity following oral administration (low dose: 0.5 mg) due to poor systemic absorption. Inhibits the actions of pentazocine when administered parenterally.
Use: Labeled Indications
Pain management: Management of moderate to severe pain severe enough to require and opioid analgesic and for which alternative treatments are inadequate.
Limitations of use: Reserve for use in patients whom alternative treatment options (eg, nonopioid analgesics) are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.
Hypersensitivity (eg, anaphylaxis) to pentazocine, naloxone, or any component of the formulation; significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment.
Documentation of allergenic cross-reactivity for opioids is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.
Pain management: Oral: One tablet (pentazocine 50 mg/naloxone 0.5 mg) every 3 to 4 hours; may increase to 2 tablets (pentazocine 100 mg/naloxone 1 mg) if needed. Maximum daily dose: 12 tablets (pentazocine 600 mg/naloxone 6 mg) per day.
Discontinuation of therapy: For patients on long term opioid therapy, decrease dose gradually; monitor carefully for signs/symptoms of withdrawal.
Refer to adult dosing. Use with caution; may be more sensitive to analgesic and sedative effects; decrease initial dose when appropriate and monitor closely.
Pain management: Oral: Children ≥12 years and Adolescents: Refer to adult dosing.
Dosing: Renal Impairment
There are no dosage adjustments provided in the manufacturer’s labeling. Use with caution. The following recommendations have been used by some clinicians based on pentazocine component (Aronoff 2007):
GFR ≥50 mL/minute: No dosage adjustment necessary
GFR 10 to 50 mL/minute: Administer 75% of normal dose
GFR <10 mL/minute: Administer 50% of normal dose
Dosing: Hepatic Impairment
There are no dosage adjustments provided in the manufacturer's labeling. Use with caution.
Store at 20°C to 25°C (68°F to 77°F).
Alvimopan: Opioid Analgesics may enhance the adverse/toxic effect of Alvimopan. This is most notable for patients receiving long-term (i.e., more than 7 days) opiates prior to alvimopan initiation. Management: Alvimopan is contraindicated in patients receiving therapeutic doses of opioids for more than 7 consecutive days immediately prior to alvimopan initiation. Consider therapy modification
Amphetamines: May enhance the analgesic effect of Opioid Analgesics. Monitor therapy
Anticholinergic Agents: May enhance the adverse/toxic effect of Opioid Analgesics. Specifically, the risk for constipation and urinary retention may be increased with this combination. Monitor therapy
Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination
Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification
Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Buprenorphine: Opioids (Mixed Agonist / Antagonist) may diminish the therapeutic effect of Buprenorphine. This combination may also induce opioid withdrawal. Avoid combination
Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification
Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
CNS Depressants: May enhance the CNS depressant effect of Opioid Analgesics. Management: Avoid concomitant use of opioid analgesics and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Desmopressin: Opioid Analgesics may enhance the adverse/toxic effect of Desmopressin. Monitor therapy
Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Diuretics: Opioid Analgesics may enhance the adverse/toxic effect of Diuretics. Opioid Analgesics may diminish the therapeutic effect of Diuretics. Monitor therapy
Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (e.g., opioids, barbiturates) with concomitant use. Consider therapy modification
Eluxadoline: Opioid Analgesics may enhance the constipating effect of Eluxadoline. Avoid combination
Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification
Gastrointestinal Agents (Prokinetic): Opioid Analgesics may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy
Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Methotrimeprazine: May enhance the CNS depressant effect of CNS Depressants. CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification
Methylnaltrexone: May enhance the adverse/toxic effect of Opioid Antagonists. Specifically, the risk for opioid withdrawal may be increased. Avoid combination
MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy
Minocycline: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Naldemedine: Opioid Antagonists may enhance the adverse/toxic effect of Naldemedine. Specifically, the risk for opioid withdrawal may be increased. Avoid combination
Nalmefene: May diminish the therapeutic effect of Opioid Analgesics. Management: Avoid the concomitant use of nalmefene and opioid analgesics. Discontinue nalmefene 1 week prior to any anticipated use of opioid analgesics. If combined, larger doses of opioid analgesics will likely be required. Consider therapy modification
Naloxegol: Opioid Antagonists may enhance the adverse/toxic effect of Naloxegol. Specifically, the risk for opioid withdrawal may be increased. Avoid combination
Naltrexone: May diminish the therapeutic effect of Opioid Analgesics. Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Consider therapy modification
Opioid Analgesics: Opioids (Mixed Agonist / Antagonist) may diminish the analgesic effect of Opioid Analgesics. Management: Seek alternatives to mixed agonist/antagonist opioids in patients receiving pure opioid agonists, and monitor for symptoms of therapeutic failure/high dose requirements (or withdrawal in opioid-dependent patients) if patients receive these combinations. Exceptions: Buprenorphine; Butorphanol; Meptazinol; Nalbuphine; Pentazocine. Avoid combination
Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination
Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination
Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination
Pegvisomant: Opioid Analgesics may diminish the therapeutic effect of Pegvisomant. Monitor therapy
Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification
Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy
Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy
Ramosetron: Opioid Analgesics may enhance the constipating effect of Ramosetron. Monitor therapy
ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy
Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy
Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy
Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy
Serotonin Modulators: Opioid Analgesics may enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Exceptions: Nicergoline. Monitor therapy
Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification
Succinylcholine: May enhance the bradycardic effect of Opioid Analgesics. Monitor therapy
Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification
Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination
Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification
Frequency not defined.
Cardiovascular: Circulatory depression, facial edema, flushing, hypertension, hypotension, syncope, tachycardia
Central nervous system: Central nervous system depression, chills, confusion, disorientation, dizziness, drowsiness, drug dependence, euphoria, excitement, hallucination, headache, increased intracranial pressure, insomnia, irritability, nightmares, paresthesia, sedation, seizure, withdrawal syndrome
Dermatologic: Dermatitis, diaphoresis, erythema multiforme, pruritus, skin rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria
Gastrointestinal: Abdominal distress, anorexia, biliary tract spasm, constipation, diarrhea, nausea, vomiting, xerostomia
Genitourinary: Urinary retention
Hematologic & oncologic: Agranulocytosis (rare), decreased white blood cell count, eosinophilia
Neuromuscular & skeletal: Tremor, weakness
Ophthalmic: Blurred vision, miosis
Respiratory: Respiratory depression (rare)
Limited to important or life-threatening: Hypogonadism (Brennan, 2013; Debono, 2011)
Concerns related to adverse effects:
• Cardiovascular effects: Pentazocine may increase systemic and pulmonary arterial pressure and systemic vascular resistance; use with caution in patients who may not tolerate these alterations in hemodynamics (eg, acute MI) and in patients with MI who have nausea or vomiting.
• CNS effects: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving). Confusion, disorientation, and visual hallucinations have occurred in some patients, but usually clears within a few hours; observe patients closely.
• Constipation: May cause constipation which may be problematic in patients with unstable angina and patients post-myocardial infarction. Consider preventive measures (eg, stool softener, increased fiber) to reduce the potential for constipation.
• Respiratory depression: [US Boxed Warning]: Serious, life-threatening, or fatal respiratory depression may occur. Monitor closely for respiratory depression, especially during initiation or dose escalation. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
• Abdominal conditions: May obscure diagnosis or clinical course of patients with acute abdominal conditions.
• Adrenal insufficiency: Use with caution in patients with adrenal insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction, infertility, mood disorders, and osteoporosis (Brennan 2013).
• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction, including acute pancreatitis; may cause constriction of sphincter of Oddi.
• Bowel disease: Use with caution in patients with inflammatory or obstructive bowel disease.
• CNS depression/coma: Avoid use in patients with CNS depression or coma as these patients are susceptible to intracranial effects of CO2 retention.
• Delirium tremens: Use with caution in patients with delirium tremens.
• Ethanol use: Use with caution due to the potential for increased risk of CNS depressant effects.
• Head trauma: Use with extreme caution in patients with head injury, intracranial lesions, or elevated intracranial pressure; exaggerated elevation of ICP may occur.
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Mental health conditions: Use opioids with caution for chronic pain in patients with mental health conditions (eg, depression, anxiety disorders, post-traumatic stress disorder) due to increased risk for opioid use disorder and overdose; more frequent monitoring is recommended (Dowell [CDC 2016]).
• Obesity: Use with caution in patients who are morbidly obese.
• Porphyria: Use with caution in patients with a history of porphyria; may exacerbate condition.
• Prostatic hyperplasia/urinary stricture: Use with caution in patients with prostatic hyperplasia and/or urinary stricture.
• Psychosis: Use with caution in patients with toxic psychosis.
• Renal impairment: Use with caution in patients with renal impairment.
• Respiratory disease: Use with caution and monitor for respiratory depression in patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or preexisting respiratory depression, particularly when initiating and titrating therapy; critical respiratory depression may occur, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Seizures: Use with caution in patients with a history of seizure disorders; may cause or exacerbate preexisting seizures.
• Sleep-disordered breathing: Use opioids with caution for chronic pain and titrate dosage cautiously in patients with risk factors for sleep-disordered breathing, including HF and obesity. Avoid opioids in patients with moderate to severe sleep-disordered breathing (Dowell [CDC 2016]).
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Benzodiazepines or other CNS depressants: [US Boxed Warning]: Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of pentazocine/naloxone and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate. Limit dosage and durations to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation.
• CYP3A4 interactions: [US Boxed Warning]: Use with all CYP450 3A4 inhibitors may result in an increase in pentazocine plasma concentrations, which could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used CYP450 3A4 inducer may result in an increase in pentazocine plasma concentration. Monitor patients receiving pentazocine/naloxone and any CYP3A4 inhibitor or inducer.
• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
• Cachectic or debilitated patients: Use with caution in cachectic or debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Elderly: Use with caution in the elderly; may be more sensitive to adverse effects. Decrease initial dose when appropriate. Use opioids for chronic pain with caution in this age group; monitor closely due to an increased potential for risks, including certain risks such as falls/fracture, cognitive impairment, and constipation. Clearance may also be reduced in older adults (with or without renal impairment) resulting in a narrow therapeutic window and increasing the risk for respiratory depression or overdose (Dowell [CDC 2016]). Consider the use of alternative nonopioid analgesics in these patients.
• Neonates: Neonatal withdrawal syndrome: [US Boxed Warning]: Prolonged use of opioids during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and requires management according to protocols developed by neonatology experts. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure appropriate treatment will be available. Signs and symptoms include irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity depend on the drug used, duration of use, maternal dose, and rate of drug elimination by the newborn.
• Smokers: Pentazocine clearance may be increased.
• Abuse/misuse/diversion: [US Boxed Warning]: Use exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Assess each patient's risk prior to prescribing pentazocine/naloxone, and monitor all patients regularly for the development of these behaviors or conditions. Use with caution in patients with a history of drug abuse, acute alcoholism, or mental illness (eg, major depression); potential for drug dependency exists. Tolerance, psychological, and physical dependence may occur with prolonged use. Other factors associated with increased risk include younger age and psychotropic medication use. Consider offering naloxone prescriptions in patients with factors associated with an increased risk for overdose, such as history of overdose or substance use disorder, higher opioid dosages (≥50 morphine milligram equivalents/day orally), and concomitant benzodiazepine use (Dowell [CDC 2016]).
• Accidental ingestion: [US Boxed Warning]: Accidental ingestion of even one dose of pentazocine/naloxone, especially in children, can result in a fatal overdose of pentazocine.
• Appropriate use: Chronic pain (outside of end-of-life or palliative care, active cancer treatment, sickle cell disease, or medication-assisted treatment for opioid use disorder) in outpatient setting in adults: Opioids should not be used as first-line therapy for chronic pain management (pain >3-month duration or beyond time of normal tissue healing) due to limited short-term benefits, undetermined long-term benefits, and association with serious risks (eg, overdose, MI, auto accidents, risk of developing opioid use disorder). Preferred management includes nonpharmacologic therapy and nonopioid therapy (eg, NSAIDs, acetaminophen, certain anticonvulsants and antidepressants). If opioid therapy is initiated, it should be combined with nonpharmacologic and non-opioid therapy, as appropriate. Prior to initiation, known risks of opioid therapy should be discussed and realistic treatment goals for pain/function should be established, including consideration for discontinuation if benefits do not outweigh risks. Therapy should be continued only if clinically meaningful improvement in pain/function outweighs risks. Therapy should be initiated at the lowest effective dosage using immediate-release opioids (instead of extended-release/long-acting opioids). Risk associated with use increases with higher opioid dosages. Risks and benefits should be re-evaluated when increasing dosage to ≥50 morphine milligram equivalents (MME)/day orally; dosages ≥90 MME/day orally should be avoided unless carefully justified (Dowell [CDC 2016]).
• Optimal regimen: An opioid-containing analgesic regimen should be tailored to each patient's needs and based upon the type of pain being treated (acute versus chronic), the route of administration, degree of tolerance for opioids (naive versus chronic user), age, weight, and medical condition. The optimal analgesic dose varies widely among patients; doses should be titrated to pain relief/prevention.
• Surgery: Opioids decrease bowel motility; monitor for decreased bowel motility in postoperative patients receiving opioids. Patients interrupting therapy to undergo pain-relieving procedures (eg, chordotomy) may require a dosage adjustment when resuming therapy after the postoperative recovery period.
• Withdrawal: Concurrent use of agonist/antagonist (eg, pentazocine, nalbuphine, butorphanol) or partial agonist (eg, buprenorphine) analgesics may precipitate withdrawal symptoms and/or reduced analgesic efficacy in patients following prolonged therapy with mu opioid agonists. Abrupt discontinuation following prolonged use may also lead to withdrawal symptoms; taper dose to decrease risk of withdrawal symptoms. Taper dose gradually when discontinuing.
Relief of pain, respiratory (within the first 24 to 72 hours of initiation and following dosage increases) and mental status; signs or symptoms of hypogonadism or hypoadrenalism (Brennan 2013)
Alternate recommendations: Chronic pain (long-term therapy outside of end-of-life or palliative care, active cancer treatment, sickle cell disease, or medication-assisted treatment for opioid use disorder): Evaluate benefits/risks of opioid therapy within 1 to 4 weeks of treatment initiation and with dose increases. Re-evaluate benefits/risks every 3 months during therapy or more frequently in patients at increased risk of overdose or opioid use disorder. Urine drug testing is recommended prior to initiation and re-checking should be considered at least yearly (includes controlled prescription medications and illicit drugs of abuse). State prescription drug monitoring program (PDMP) data should be reviewed by clinicians prior to initiation and periodically during therapy (frequency ranging from every prescription to every 3 months) (Dowell [CDC 2016]).
[US Boxed Warning]: Prolonged use of opioids during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and requires management according to protocols developed by neonatology experts. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure appropriate treatment will be available. See individual agents.
• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience nausea, vomiting, sweating a lot, diarrhea, dry mouth, abdominal pain, or lack of appetite. Have patient report immediately to prescriber signs of serotonin syndrome (dizziness, severe headache, agitation, hallucinations, tachycardia, abnormal heartbeat, flushing, tremors, sweating a lot, change in balance, severe nausea, or severe diarrhea), signs of adrenal gland problems (severe nausea, vomiting, severe dizziness, passing out, muscle weakness, severe fatigue, mood changes, lack of appetite, or weight loss), sexual dysfunction (males), amenorrhea, decreased libido, infertility, severe headache, severe dizziness, passing out, difficulty breathing, slow breathing, shallow breathing, severe fatigue, confusion, severe constipation, severe loss of strength and energy, hallucinations, seizures, angina, tachycardia, vision changes, difficult urination, mood changes, chills, pharyngitis, or burning or numbness feeling (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.
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