Naloxone and Pentazocine

Pentazocine and Naloxone Hydrochloride Tablets are indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Limitations of Use Because of the risks of addiction, abuse, and misuse, with opioids, even at recommended doses, reserve Pentazocine and Naloxone Tablets for use in patients for whom alternative treatment options [e.g., non-opioid analgesics] Have not been tolerated, or are not expected to be tolerated, Have not provided adequate analgesia, or are not expected to provide adequate analgesia

Pentazocine is a mixed agonist-antagonist at opioid receptors. Pentazocine is a partial agonist at the mu opioid receptor and an agonist at the kappa opioid receptor. Naloxone is an opioid antagonist. Pharmacodynamics Effects on the Central Nervous System Pentazocine produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation. Pentazocine causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations.

Important Dosage and Administration Instructions Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals. Initiate the dosing regimen for each patient individually, taking into account the patient's severity of pain, patient response, prior analgesic treatment experience, and risk factors for addiction, abuse, and misuse. Monitor patients closely for respiratory depression, especially within the first 24 to 72 hours of initiating therapy and following dosage increases with Pentazocine and Naloxone Tablets and adjust the dosage accordingly. Initial Dosage Use of Pentazocine and Naloxone Tablets as the First Opioid Analgesic Initiate treatment with pentazocine hydrochloride and naloxone hydrochloride tablets, USP in a dosing range of 1 tablet every three to four hours. This may be increased to 2 tablets when needed.

Pentazocine and Naloxone Hydrochloride Tablets, are contraindicated in patients with: Significant respiratory depression Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment. Patients with known or suspected gastrointestinal obstruction, including paralytic ileus Patients with hypersensitivity to either pentazocine, naloxone, or any of the formulation excipients (e.g., anaphylaxis).

Boxed warning: Addiction, Abuse, and Misuse Pentazocine and Naloxone Tablets 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 and Naloxone Tablets, and monitor all patients regularly for the development of these behaviors and conditions. Addiction, Abuse, and Misuse Pentazocine and Naloxone Tablets contain pentazocine, a Schedule IV controlled substance. As an opioid, Pentazocine and Naloxone Tablets expose users to the risks of addiction, abuse, and misuse. Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed Pentazocine and Naloxone Tablets. Addiction can occur at recommended dosages and if the drug is misused or abused.

The following adverse reactions associated with the use of pentazocine and naltrexone were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cardiovascular - Hypertension, hypotension, circulatory depression, tachycardia, syncope. Respiratory - Rarely, respiratory depression. Acute CNS Manifestations - Hallucinations (usually visual), disorientation, and confusion. Other CNS Effects - Grand mal convulsions, increase in intracranial pressure, dizziness, lightheadedness, hallucinations, sedation, euphoria, headache, confusion, disorientation, infrequently weakness, disturbed dreams, insomnia, syncope, and depression, and rarely tremor, irritability, excitement, tinnitus.

Interactions Drug Interactions Benzodiazepines and Other Central Nervous System (CNS) Depressants Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants including alcohol, benzodiazepines and other sedative hypnotics, anxiolytics, and tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients closely for signs of respiratory depression and sedation.

Store at controlled room temperature 15˚ C to 30˚ C (59˚ F to 86˚ F).