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Class: Opioid agonist-antagonist analgesic
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 AdministrationAdults 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).Pentazocine/Naloxone
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).
- For oral use only.
- May administer pentazocine/naloxone with aspirin if needed.
Store at 68° to 77°F.
Causes additive CNS depression. Use with caution.Barbiturate anesthetics and any other CNS depressants (eg, antidepressants, benzodiazepines)
Causes increased CNS and respiratory depression.
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.
Allergic reactions (eg, agranulocytosis, edema of the face, hemolytic anemia, skin rashes, thrombocytopenic purpura), chills, urinary retention.
WarningsPentazocine / 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.
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.
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.
- 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.
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