Pentazocine hydrochloride with Naloxone hydrochloride
Pentazocine hydrochloride with Naloxone (Talwin NX)
Pentazocine with Naloxone
(pen- TAZ-oh-seen, nah- LOX-ohn)
Pregnancy Category: C Talwin NX (C-IV) (Rx)
Pentazocine lactate
Pentazocine lactate (Talwin)
Pentazocine
(pen- TAZ-oh-seen)
Pregnancy Category: C Talwin (C-IV) (Rx)

Classification: Narcotic agonist/antagonist

See Also: See also Narcotic Analgesics .

Content: Each tablet of pentazocine HCl with naloxone HCl contains: pentazocine HCl, 50 mg, and naloxone HCl, 0.5 mg.

Action/Kinetics: Manifests both narcotic agonist and antagonist properties. Agonist effects are due to combination with kappa and sigma opioid receptors; antagonistic effect is due to an action on mu opioid receptors. Also elevates systemic and pulmonary arterial pressure, systemic vascular resistance, and LV end-diastolic pressure, which results in an increased cardiac workload. One-third as potent as morphine as an analgesic. Onset: IM, 15-20 min; PO, 15-30 min; IV, 2-3 min. Peak effect: IM, 15-60 min; PO, 60-180 min. Duration, all routes: 3 hr. However, onset, duration, and degree of relief depend on both dose and severity of pain. t 1/2: 2-3 hr. Extensive first-pass metabolism in the liver.
To reduce the possibility of abuse, the PO dosage form of pentazocine has been combined with naloxone (Talwin NX), which will prevent the effects of IV administered pentazocine but will not affect the efficacy of pentazocine when taken PO. If pentazocine with naloxone is used IV, fatal reactions may occur, which include vascular occlusion, pulmonary emboli, ulceration, and abscesses, and withdrawal in narcotic-dependent individuals.

Uses: PO: Moderate to severe pain. Parenteral: Preoperative or preanesthetic medication, obstetrics, supplement to surgical anesthesia. Moderate to severe pain.

Additional Contraindications Increased ICP or head injury. Use in children under 12 years of age. Use of methadone or other narcotics for pentazocine withdrawal.

Special Concerns: Use with caution in impaired renal or hepatic function, as well as after MI, when N&V are present. Use with caution in women delivering premature infants and in clients with respiratory depression. Safety and efficacy in children less than 12 years of age have not been determined.

Additional Side Effects CNS: Syncope, dysphoria, nightmares, hallucinations, disorientation, paresthesias, confusion, seizures. Miscellaneous; Decreased WBCs, edema of the face, chills. Both psychologic and physical dependence are possible, although the addiction liability is thought to be no greater than for codeine. Multiple parenteral doses may cause severe sclerosis of the skin, SC tissues, and underlying muscle.

How Supplied: Pentazocine hydrochloride with Naloxone hydrochloride: See Content. Pentazocine lactate: Injection: 30 mg/mL

Dosage

Pentazocine hydrochloride with naloxone •Tablets Analgesia.
Adults: 50 mg q 3-4 hr, up to 100 mg. Daily dose should not exceed 600 mg.

Pentazocine lactate •IM, IV, SC Analgesia.
Adults: 30 mg q 3-4 hr; doses exceeding 30 mg IV or 60 mg IM not recommended. Do not exceed a total daily dosage of 360 mg.
Obstetric analgesia.
Adults: 30 mg IM given once; or, 20 mg IV q 2-3 hr for two or three doses.