Cardiovascular
Hypertension, hypotension, circulatory depression, tachycardia, syncope. Respiratory.
Rarely, respiratory depression.
Acute CNS Manifestations
Patients receiving therapeutic doses of pentazocine have experienced hallucinations
(usually visual), disorientation, and confusion which have cleared spontaneously
within a period of hours. The mechanism of this reaction is not known. Such
patients should be closely observed and vital signs checked. If the drug is
reinstituted it should be done with caution since these acute CNS manifestations
may recur.
Other CNS Effects
Grand mal convulsions, increase in intracranial pressure, dizziness, lightheadedness,
hallucinations, sedation, euphoria, headache, confusion, disorientation; infrequently
weakness, disturbed dreams, insomnia, syncope, visual blurring and focusing
difficulty, depression; and rarely tremor, irritability, excitement, tinnitus.
Autonomic
Sweating; infrequently flushing; and rarely chills.
Gastrointestinal
Nausea, vomiting, constipation, diarrhea, anorexia, dry mouth, biliary tract
spasm, and rarely abdominal distress.
Allergic
Edema of the face; anaphylactic shock; dermatitis, including pruritus; flushed
skin, including plethora; infrequently rash, and rarely urticaria.
Ophthalmic
Visual blurring and focusing difficulty, miosis.
Hematologic
Depression of white blood cells (especially granulocytes), with rare cases
of agranulocytosis, which is usually reversible, moderate transient eosinophilia.
Dependence and Withdrawal Symptoms. (See WARNINGS,
PRECAUTIONS, and Drug Abuse And Dependence
Sections).
Other
Headache, chills, insomnia, weakness, urinary retention, paresthesia, serious
skin reactions, including erythema multiforme, Stevens-Johnson syndrome toxic
epidermal necrolysis, and alterations in rate or strength of uterine contractions
during labor.
Drug Abuse And Dependence
Controlled Substance
TALWIN Nx is a Schedule IV controlled substance. Abuse and addiction are separate
and distinct from physical dependence and tolerance. Abuse is characterized
by misuse of a drug for non-medical purposes, often in combination with other
psychoactive substances. Addiction is a disease of repeated drug abuse. Addiction
is a primary, chronic, neurobiologic disease, with genetic, psychosocial, and
environmental factors influencing its development and manifestations. Addiction
is characterized by behaviors that include one or more of the following: impaired
control over drug use, compulsive use, continued use despite harm, and craving.
Drug addiction is a treatable disease, utilizing a multidisciplinary approach,
but relapse is common. Physical dependence is a state of adaptation that is
manifested by a specific withdrawal syndrome that can be produced by abrupt
cessation, rapid dose reduction, decreasing blood level of the drug, and/or
administration of an antagonist. Tolerance is a state of adaptation in which
exposure to a drug induces changes that result in a diminution of one or more
of the drug's effects lerance may occur to both the desired and undesired effects
of drugs, and may develop at different rates for different effects.
Physicians should be aware that addiction may not be accompanied by concurrent
tolerance and symptoms of physical dependence in all addicts. In addition, abuse
of opioids can occur in the absence of addiction and is characterized by misuse
of the drug for non-medical purposes, and often in combination with other psychoactive
substances.
There have been some reports of dependence and of withdrawal symptoms with
orally administered pentazocine. Patients with a history of drug dependence
should be under close supervision while receiving pentazocine orally. There
have been rare reports of possible abstinence syndromes in newborns after prolonged
use of pentazocine during pregnancy.
There have been reports of development of addiction and physical dependence
in patients receiving parenteral pentazocine. People with a history of drug
abuse or alcohol abuse may have a higher chance of becoming addicted to opioid
medicines.
Abrupt dose cessation or rapid dose reduction following the extended use of
parenteral pentazocine has resulted in withdrawal symptoms such as abdominal
cramps, nausea, vomiting, elevated temperature, chills, rhinorrhea, restlessness,
anxiety, or lacrimation. In general opioid therapy should not be abruptly discontinued.
When the patient no longer requires treatment with Talwin Nx, the drug should
be tapered gradually to prevent signs and symptoms of withdrawal in patients
who have been receiving opioids for an extended period of time and might have
become physically dependent.
In prescribing pentazocine for chronic use, the physician should take under
consideration that proper assessment of the patient, proper prescribing practices,
periodic re-evaluation of therapy, and proper dispensing and storage are appropriate
measures that help to identify and decrease misuse and abuse of opioid drugs.
The amount of naloxone present in TALWIN Nx (0.5 mg per tablet) has no action
when taken orally and will not interfere with the pharmacologic action of pentazocine.
However, this amount of naloxone given by injection has profound antagonistic
action to narcotic analgesics.
Severe, even lethal, consequences may result from misuse of tablets by injection
either alone or in combination with other substances, such as pulmonary emboli,
vascular occlusion, ulceration and abscesses, and withdrawal symptoms in narcotic
dependent individuals.
TALWIN Nx contains an opioid antagonist, naloxone (0.5 mg). Naloxone is inactive
when administered orally at this dose, and its inclusion in TALWIN Nx is intended
to curb a form of misuse of oral pentazocine. Parenterally, naloxone is an active
narcotic antagonist. Thus, TALWIN Nx has a lower potential for parenteral misuse
than the previous oral pentazocine formulation TALWIN® 50 (pentazocine hydrochloride
tablets, USP). However, it is still subject to patient misuse and abuse by the
oral route.
TALWIN® Nx is intended for oral use only. Severe, potentially lethal, reactions
may result from misuse of TALWIN® Nx by injec tion either alone or in combination
with other substances. (See Drug Abuse And Dependence section.)