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Pentazocine Combinations

Pronunciation: pen-TAZ-oh-seen
Class: Opioid agonist-antagonist analgesic

Trade Names

Pentazocine / Acetaminophen
- Tablets pentazocine 25 mg/acetaminophen 650 mg

Pentazocine / Naloxone
- Tablets pentazocine 50 mg/naloxone 0.5 mg


Produces analgesia by an agonistic effect at the kappa opioid receptor. Weakly antagonizes effects of opiates at mu opioid receptor.

Indications and Usage

Relief of mild to moderate pain (pentazocine/acetaminophen); management of moderate to severe pain (pentazocine/naloxone).


Hypersensitivity to pentazocine, acetaminophen, or naloxone.

Dosage and Administration

Adults and Children 12 y of age and older Pentazocine/Acetaminophen

PO pentazocine 25 mg/acetaminophen 650 mg every 4 h (max, 150 mg/3,900 mg per day).


PO pentazocine 50 mg/naloxone 0.5 mg every 3 to 4 h; increase to pentazocine 100 mg/naloxone 1 mg if necessary (max, 600 mg/6 mg per day).

General Advice

  • For oral use only.
  • May administer pentazocine/naloxone with aspirin if needed.


Store at 68° to 77°F.

Drug Interactions


Causes additive CNS depression. Use with caution.

Barbiturate anesthetics and any other CNS depressants (eg, antidepressants, benzodiazepines)

Causes increased CNS and respiratory depression.

Adverse Reactions


Hypotension, syncope, tachycardia.


Confusion, depression, disorientation, disturbed dreams, dizziness, euphoria, excitement, hallucinations, headache, insomnia, irritability, light-headedness, paresthesia, sedation, tremor, weakness.


Dermatitis including pruritus, erythema multiforme, flushed skin including plethora, rash, Stevens-Johnson syndrome, sweating, TEN, urticaria.


Tinnitus, visual blurring and focusing difficulty.


Abdominal distress, anorexia, constipation, diarrhea, nausea, vomiting.


Eosinophilia, granulocytopenia.


Respiratory depression.


Allergic reactions (eg, agranulocytosis, edema of the face, hemolytic anemia, skin rashes, thrombocytopenic purpura), chills, urinary retention.



Pentazocine / Acetaminophen

This product contains acetaminophen. Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4,000 milligrams per day, and often involve more than one acetaminophen-containing product.

Pentazocine / Naloxone

For oral use only. Severe, potentially lethal reactions (eg, pulmonary emboli, vascular occlusion, ulcerations and abscesses, withdrawal symptoms in narcotic-dependent individuals) may result from misuse of this drug by injection or in combination with other substances.


Category C .




Safety and efficacy not established in children younger than 12 y of age.


Use caution in dose selection, 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.

Labor and Delivery

Use drug with caution in women delivering premature infants.

Special Risk Patients

Use with caution in patients with MI who have cyanosis, decreased respiratory reserve, head injury, increased intracranial pressure, nausea and vomiting, obstructive pulmonary conditions, respiratory depression, seizure, or severe bronchial asthma.

Sulfite Sensitivity

Some of these products may cause allergic-type reactions (eg, anaphylaxis, hives, itching, wheezing) in susceptible persons.


Abuse potential exists. Abrupt discontinuation after long-term use may cause withdrawal symptoms. Do not substitute other opiates in pentazocine withdrawal syndrome. Pentazocine may induce withdrawal symptoms in narcotic-dependent patients.

Acute CNS manifestations

Confusion, disorientation, hallucinations, and seizures.

Biliary surgery

May elevate biliary tract pressure.

Renal or hepatic function impairment

Duration of action may be prolonged; dosage reduction may be required.



Hypertension, respiratory depression, tachycardia.

Patient Information

  • For maximum effectiveness, instruct patient to take medication before intolerable pain develops.
  • Tell patient to take medication exactly as prescribed to minimize dependence.
  • Caution patient not to stop taking drug abruptly without consulting health care provider.
  • Advise patient to avoid sudden position changes to prevent orthostatic hypotension.
  • Instruct patient to avoid intake of alcoholic beverages or other CNS depressants.
  • Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness.
  • Inform patient that aspirin may be taken concurrently with pentazocine/naloxone for additive analgesics, as well its anti-inflammatory and antipyretic effects.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.