Contains sodium metabisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic people.
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, TALACEN must be used with extreme caution and only if its use is deemed essential.
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.
There have been instances of psychological and physical dependence on parenteral pentazocine in patients with a history of drug abuse, and rarely, in patients without such a history. (See DRUG ABUSE AND DEPENDENCE.)
Due to the potential for increased CNS depressant effects, alcohol should be used with caution in patients who are currently receiving pentazocine.
Pentazocine may precipitate opioid abstinence symptoms in patients receiving courses of opiates for pain relief.
There is currently no manufacturer warning information available for this drug.
TALACEN is a combination of pentazocine hydrochloride, USP, equivalent to 25 mg base and acetaminophen, USP, 650 mg.
Pentazocine is a member of the benzazocine series (also known as the benzomorphan series). Chemically, pentazocine is (2R*, 6R*, 11R*)1,2,3,4,5,6-hexahydro-6,11-dimethyl-3-(3-methyl-2-butenyl)-2,6-methano-3-benzazocin-8-ol, a white, crystalline substance soluble in acidic aqueous solutions, and has the following structural formula:
Chemically, acetaminophen is Acetamide, N-(4-hydroxyphenyl)-, and has the following structural formula:
Pentazocine is an analgesic and acetaminophen is an analgesic and antipyretic.
Inactive Ingredients: Colloidal Silicon Dioxide, FD&C Blue #1, Gelatin, Microcrystalline Cellulose, Potassium Sorbate, Pregelatinized Starch, Sodium Lauryl Sulfate, Sodium Metabisulfite, Sodium Starch Glycolate, Stearic Acid.
