Drug Dependence

Pentazocine can cause a physical and psychological dependence. (See ADVERSE REACTIONS: DRUG ABUSE AND DEPENDENCE subsection.)

Head Injury and Increased Intracranial Pressure

As in the case of other potent analgesics, the potential of pentazocine for elevating cerebrospinal fluid pressure may be attributed to CO₂ retention due to the respiratory depressant effects of the drug. These effects may be markedly exaggerated in the presence of head injury, other intracranial lesions, or a preexisting increase in intracranial pressure. Furthermore, pentazocine can produce effects which may obscure the clinical course of patients with head injuries. In such patients, pentazocine must be used with extreme caution and only if its use is deemed essential.

Usage with Alcohol

Due to the potential for increased CNS depressants effects, alcohol should be used with caution in patients who are currently receiving pentazocine.

Patients Receiving Narcotics

Pentazocine is a mild narcotic antagonist. Some patients previously given narcotics, including methadone for the daily treatment of narcotic dependence, have experienced withdrawal symptoms after receiving pentazocine.

Certain Respiratory Conditions

Although respiratory depression has rarely been reported after oral administration of pentazocine, the drug should be administered with caution to patients with respiratory depression from any cause, severely limited respiratory reserve, severe bronchial asthma, and other obstructive respiratory conditions, or cyanosis.

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 very closely observed and vital signs checked. If the drug is reinstituted, it should be done with caution since these acute CNS manifestations may recur.

CNS Effect

Caution should be used when pentazocine is administered to patients prone to seizures; seizures have occurred in a few such patients in association with the use of pentazocine though no cause and effect relationship has been established.

Impaired Renal or Hepatic Function

Decreased metabolism of pentazocine by the liver in extensive liver disease may predispose to accentuation of side effects. Although laboratory tests have not indicated that pentazocine causes or increases renal or hepatic impairment, the drug should be administered with caution to patients with such impairment.

In prescribing pentazocine for long-term use, the physician should take precautions to avoid increases in dose by the patient.

Biliary Surgery

Narcotic drug products are generally considered to elevate biliary tract pressure for varying periods following their administration. Some evidence suggests that pentazocine may differ from other marketed narcotics in this respect (i.e., it causes little or no elevation in biliary tract pressures). The clinical significance of these findings, however, is not yet known.

Carcinogenesis, Mutagenesis, Impairment of Fertility

No long-term studies in animals to test for carcinogenesis have been performed with the components of TALWIN Nx.

Pregnancy Category C

Animal reproduction studies have not been conducted with TALWIN Nx. It is also not known whether TALWIN Nx can cause fetal harm when administered to pregnant women or can affect reproduction capacity. TALWIN Nx should be given to pregnant women only if clearly needed. However, animal reproduction studies with pentazocine have not demonstrated teratogenic or embryotoxic effects.

Labor and Delivery

Patients receiving pentazocine during labor have experienced no adverse effects other than those that occur with commonly used analgesics. TALWIN Nx should be used with caution in women delivering premature infants. The effect of TALWIN Nx on the mother and fetus, the duration of labor or delivery, the possibility that forceps delivery or other intervention or resuscitation of the new-born may be necessary, or the effect of TALWIN Nx on the later growth, development, and functional maturation of the child are unknown at the present time.

Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when TALWIN Nx is administered to a nursing woman.

Pediatric Use

Safety and effectiveness in children below the age of 12 years have not been established.

Geriatric Use

Controlled clinical studies of TALWIN Nx did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses or effectiveness in analgesic activity between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, 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.

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