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ALERT: U.S. Boxed Warning
The FDA-approved labeling includes a boxed warning. See Warnings/Precautions section and/or refer to product labeling for additional detail.
Medication Safety Issues
High alert medication: The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drug classes which have a heightened risk of causing significant patient harm when used in error.
Pronunciation
(pen TAZ oh seen)
U.S. Brand Names
Index Terms
Generic Available
Yes: Tablet
Canadian Brand Names
Pharmacologic Category
Pharmacologic Category Synonyms
Use: Labeled Indications
Relief of moderate to severe pain; has also been used as a sedative prior to surgery and as a supplement to surgical anesthesia
Restrictions
C-IV
Pregnancy Risk Factor
C/D (prolonged use or high doses at term)
Pregnancy Considerations
Pentazocine was not found to be teratogenic in animal studies. Pentazocine and naloxone have been shown to cross the human placenta. Use should be avoided during labor and delivery of premature infants. Abstinence syndromes in the newborn have been reported after long-term use of pentazocine during pregnancy. Other adverse effects in the newborn have been reported following abuse of pentazocine during pregnancy; these effects may be due to pentazocine, other drugs abused, the mother's lifestyle, or a combination of all factors.
Lactation
Excretion in breast milk unknown/use caution
Breast-Feeding Considerations
Excretion of pentazocine in breast milk is unknown; no data available for naloxone
Contraindications
Hypersensitivity to pentazocine, naloxone, or any component of the formulation; increased intracranial pressure (unless the patient is mechanically ventilated); pregnancy (prolonged use or high doses at term)
Warnings/Precautions
Boxed warnings:
• Talwin® NX: See “Dosage form specific issues” below.
Concerns related to adverse effects:
• CNS depression: 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).
• Injection-site reactions: Severe sclerosis has occurred at the injection-site following multiple injections; rotate sites of injection.
• Hypotension: May cause hypotension; use with caution in patients with hypovolemia, cardiovascular disease (including acute MI), or drugs which may exaggerate hypotensive effects (including phenothiazines or general anesthetics).
Disease-related concerns:
• 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's disease.
• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction; acute pancreatitis may cause constriction of sphincter of Oddi.
• CNS depression/coma: Use with caution in patients with CNS depression or coma.
• Drug abuse: Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Tolerance, psychological and physical dependence may occur with prolonged use.
• 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 dysfunction.
• Obesity: Use with caution in patients who are morbidly obese.
• Prostatic hyperplasia/urinary stricture: Use with caution in patients with prostatic hyperplasia and/or urinary stricture.
• Renal impairment: Use with caution in patients with renal dysfunction.
• Respiratory disease: Use with caution in patients with pre-existing respiratory compromise (hypoxia and/or hypercapnia), COPD or other obstructive pulmonary disease, and kyphoscoliosis or other skeletal disorder which may alter respiratory function; critical respiratory depression may occur, even at therapeutic dosages.
• Seizures: Use with caution in patients with a history of seizure disorders.
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.
Special populations:
• Debilitated patients: Use with caution in debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages.
• Elderly: Use with caution in the elderly; may be more sensitive to adverse effects. Decrease initial dose.
• Pediatrics: Safety and efficacy have not been established in children <1 year of age.
Dosage form specific issues:
• Sulfites: Injection contains sulfites which may cause allergic reaction.
• Talwin® NX: [U.S. Boxed Warning]: Talwin® NX is intended for oral administration only - severe vascular reactions have resulted from misuse by injection.
Other warnings/precautions:
• Withdrawal: Concurrent use of agonist/antagonist 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.
Adverse Reactions
Frequency not defined.
Cardiovascular: Circulatory depression, facial edema, flushing, hypotension, shock, syncope, tachycardia
Central nervous system: Chills, CNS depression, confusion, disorientation, dizziness, drowsiness, euphoria, excitement, hallucinations, headache, insomnia, irritability, lightheadedness, malaise, nightmares, sedation
Dermatologic: Dermatitis, erythema multiforme, pruritus, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria
Gastrointestinal: Abdominal distress, anorexia, constipation, diarrhea, nausea, vomiting, xerostomia
Genitourinary: Urinary retention
Hematologic: Decreased WBCs, eosinophilia
Local: Tissue damage and irritation with I.M./SubQ use
Neuromuscular & skeletal: Paresthesia, tremor, weakness
Ocular: Blurred vision, miosis
Otic: Tinnitus
Respiratory: Dyspnea, respiratory depression (rare)
Miscellaneous: Anaphylaxis, diaphoresis, physical and psychological dependence
Drug Interactions
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Risk C: Monitor therapy
Alvimopan: Analgesics (Opioid) 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. Risk D: Consider therapy modification
Ammonium Chloride: May increase the excretion of Analgesics (Opioid). Risk C: Monitor therapy
Amphetamines: May enhance the analgesic effect of Analgesics (Opioid). Risk C: Monitor therapy
Antipsychotic Agents (Phenothiazines): May enhance the hypotensive effect of Analgesics (Opioid). Risk C: Monitor therapy
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Risk C: Monitor therapy
Pegvisomant: Analgesics (Opioid) may diminish the therapeutic effect of Pegvisomant. Risk C: Monitor therapy
Selective Serotonin Reuptake Inhibitors: Analgesics (Opioid) may enhance the serotonergic effect of Selective Serotonin Reuptake Inhibitors. This may cause serotonin syndrome. Risk C: Monitor therapy
Succinylcholine: May enhance the bradycardic effect of Analgesics (Opioid). Risk C: Monitor therapy
Ethanol/Nutrition/Herb Interactions
Ethanol: Avoid ethanol (may increase CNS depression).
Storage
Injection: Store at room temperature; do not freeze. Protect from heat.
Compatibility
Y-site administration: Compatible: Heparin, hydrocortisone sodium succinate, potassium chloride, vitamin B complex with C. Incompatible: Nafcillin.
Compatibility in syringe: Compatible: Atropine, butorphanol, chlorpromazine, cimetidine, dimenhydrinate, diphenhydramine, droperidol, fentanyl, hydromorphone, hydroxyzine, meperidine, meperidine with perphenazine, metoclopramide, morphine, perphenazine, prochlorperazine edisylate, promazine, promethazine, propiomazine, ranitidine, scopolamine. Incompatible: Glycopyrrolate, heparin, pentobarbital.
Compatibility when admixed: Incompatible: Aminophylline, amobarbital, pentobarbital, phenobarbital, sodium bicarbonate.
Mechanism of Action
Binds to opiate receptors in the CNS, causing inhibition of ascending pain pathways, altering the perception of and response to pain; produces generalized CNS depression; partial agonist-antagonist
Pharmacodynamics/Kinetics
Onset of action: Oral, I.M., SubQ: 15-30 minutes; I.V.: 2-3 minutes
Duration: Oral: 4-5 hours; Parenteral: 2-3 hours
Protein binding: 60%
Metabolism: Hepatic via oxidative and glucuronide conjugation pathways; extensive first-pass effect
Bioavailability: Oral: ?20%; increased to 60% to 70% with cirrhosis
Half-life elimination: 2-3 hours; prolonged with hepatic impairment
Excretion: Urine (small amounts as unchanged drug)
Dosage
Preoperative/preanesthetic: Children 1-16 years: I.M.: 0.5 mg/kg
Analgesia:
Children: I.M.:
5-8 years: 15 mg
8-14 years: 30 mg
Children >12 years and Adults: Oral: 50 mg every 3-4 hours; may increase to 100 mg/dose if needed, but should not exceed 600 mg/day
Adults:
I.M., SubQ: 30-60 mg every 3-4 hours; do not exceed 60 mg/dose (maximum: 360 mg/day)
I.V.: 30 mg every 3-4 hours; do not exceed 30 mg/dose (maximum: 360 mg/day)
Elderly: Elderly patients may be more sensitive to the analgesic and sedating effects. The elderly may also have impaired renal function. If needed, dosing should be started at the lower end of dosing range and adjust dose for renal function.
Dosing adjustment in renal impairment:
Clcr 10-50 mL/minute: Administer 75% of normal dose
Clcr <10 mL/minute: Administer 50% of normal dose
Dosing adjustment in hepatic impairment: Reduce dose or avoid use in patients with liver disease
Administration: I.M.
Rotate injection site; avoid intra-arterial injection
Administration: Other
Rotate injection site for SubQ use; avoid SubQ use unless absolutely necessary (may cause tissue damage); avoid intra-arterial injection
Administration: I.V. Detail
pH: 4-5 (adjusted with lactic acid or sodium hydroxide)
Monitoring Parameters
Relief of pain, respiratory and mental status, blood pressure
Patient Education
If self-administered, use exactly as directed; do not increase dose or frequency. Drug may cause physical and/or psychological dependence. While using this medication, do not use alcohol and other prescription or OTC medications (especially sedatives, tranquilizers, antihistamines, or pain medications) without consulting prescriber. Maintain adequate hydration (2-3 L/day of fluids) unless instructed to restrict fluid intake. May cause hypotension, dizziness, drowsiness, impaired coordination, or blurred vision (use caution when driving, climbing stairs, or changing position - rising from sitting or lying to standing, or when engaging in tasks requiring alertness until response to drug is known); nausea, vomiting, loss of appetite, or dry mouth (frequent mouth care, small frequent meals, chewing gum, or sucking lozenges may help); or constipation (increased exercise, fluids, fruit, or fiber may help; if unresolved, consult prescriber about use of stool softeners). Report persistent dizziness or headache; excessive fatigue or sedation; changes in mental status; changes in urinary elimination or pain on urination; weakness or trembling; blurred vision; or shortness of breath. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to become pregnant. Consult prescriber if breast-feeding.
Geriatric Considerations
Pentazocine is not recommended for use in the elderly because of its propensity to cause delirium and agitation. If pentazocine must be used, be sure to adjust dose for renal function.
Additional Information
Pentazocine hydrochloride: Talwin® NX tablet (with naloxone); naloxone is used to prevent abuse by dissolving tablets in water and using as injection.
Anesthesia and Critical Care Concerns/Other Considerations
Naloxone is added to the tablet form of pentazocine to prevent abuse.
Mixed agonist-antagonist: May precipitate psychomimetic effects; may precipitate withdrawal in narcotic-dependent patients.
Dental Health: Effects on Dental Treatment
Key adverse event(s) related to dental treatment: Xerostomia (normal salivary flow resumes upon discontinuation).
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
Drowsiness and euphoria are common; may cause restlessness or nightmares; may rarely cause confusion, depression, or hallucinations
Mental Health: Effects on Psychiatric Treatment
Concurrent use with psychotropics may produce additive effects or toxicity; may cause withdrawal in patients currently dependent on narcotics
Nursing: Physical Assessment/Monitoring
Assess other medications patient may be taking for additive or adverse interactions. Monitor therapeutic effectiveness, adverse reactions, and overdose at beginning of therapy and at regular intervals with long-term use. May cause physical and/or psychological dependence. For inpatients, implement safety measures. Assess knowledge/teach patient appropriate use (if self-administered), adverse reactions to report and appropriate interventions to reduce side effects..
Oncology: Vesicant
Local effects (stinging, induration, ulceration, thrombosis) have been associated with chronic use of pentazocine. I.M. injections are reported to cause less local tissue damage than SubQ injections.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Injection, solution:
Talwin®: 30 mg/mL (1 mL, 10 mL) [10 mL size contains sodium bisulfite]
Tablet: Pentazocine 50 mg and naloxone 0.5 mg
Talwin® NX: Pentazocine 50 mg and naloxone 0.5 mg
Pricing: U.S. (www.drugstore.com)
Solution (Talwin)
30 mg/mL (10): $74.42
Tablets (Pentazocine-Naloxone HCl)
50-0.5 mg (30): $40.22
Tablets (Talwin NX)
50-0.5 mg (30): $65.09
References
Alexander JI and Spence AA, “Central Nervous Effects of Pentazocine,” Br Med J, 1974, 2(912):224-5.
Challoner KR, McCarron MM, and Newton EJ, “Pentazocine (Talwin®) Intoxication: Report of 57 Cases,” J Emerg Med, 1990, 8(1):67-74.
De Bard ML and Jagger JA, “T's and B's - Midwestern Heroin Substance,” Clin Toxicol, 1981, 18(9):1117-23.
“Drugs for Pain,” Med Lett Drugs Ther, 2000, 42(1085):73-8.
Hanunen K, Olkkola KT, Seppala T, et al, “Pharmacokinetics and Pharmacodynamics of Pentazocine in Children,” Pharmacol Toxicol, 1993, 73(2):120-3.
Martin WR, “Naloxone,” Ann Intern Med, 1976, 85(6):765-8.
Mokhlesi B, Leikin JB, Murray P, et al, “Adult Toxicology in Critical Care: Part II: Specific Poisonings,” Chest, 2003, 123(3):897-922.
Ray AD and Gupta M, “Clinical Trial of Pentazocine as Analgesic in Pediatric Cases,” J Indian Med Assoc, 1994, 92(3):77-9.
Reed DA and Schnoll SH, “Abuse of Pentazocine-Naloxone Combination,” JAMA, 1986, 256(18):2562-4.
Rita L, Seleny FL, and Levin RM, “A Comparison of Pentazocine and Morphine for Pediatric Premedication,” Anesth Analg, 1970, 49(3):377-82.
Waterworth TA, “Pentazocine (Fortal) as Postoperative Analgesic in Children,” Arch Dis Child, 1974, 49(6):488-90.
International Brand Names
Lexi-Comp.com
Last full review/revision August 2008
Content last modified August 2008
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