Adult Dosing
Analgesia, moderate to severe pain
- 30 mg IM/IV/SC q3-4 hrs PRN
- Max: 30 mg (IV dose), 60 mg (IM dose), 60 mg (SC dose), 360 mg/day
Obstetric analgesia
- 30 mg IM q2-4 hrs; alt: 20 mg IV q2-4 hrs
Anesthesia adjunct
- 30 mg IM q2-4 hrs; alt: 20 mg IV q2-4 hrs
Pediatric Dosing
Anesthesia adjunct
Renal Dose Adjustment (Based on CrCl)
- 10-50 mL/min: Decrease dose by 25%
- <10 mL/min: Decrease dose by 50%
- Hemodialysis: No supplement
Hepatic Dose Adjustment
- Hepatic impairment: Use with caution; dose adjustments not defined
See Supplemental Patient Information
- Exercise special care in prescribing pentazocine for emotionally unstable patients and for those having history of drug misuse. Closely supervise such patients when >4-5 days of therapy is contemplated
- Psychological and physical dependence may occur in patients having such a history and rarely in patients without such a history
- Extended use of parenteral pentazocine may lead to physical or psychological dependence in some patients. On abrupt discontinuation withdrawal symptoms such as abdominal cramps, elevated temperature, rhinorrhea, restlessness, anxiety, and lacrimation may occur. However, even when these have occurred, discontinuation may be accomplish with minimal difficulty. In patients in whom more minor difficulty has been encountered, reinstitution of parenteral drug with gradual withdrawal has ameliorated the patient’s symptoms
- Avoid substituting methadone or other narcotics for this drug in the treatment of the pentazocine abstinence syndrome
- Abstinence syndromes in newborns may occur after prolonged use of this drug during pregnancy
- Take precautions to avoid increase in dose and frequency of injection by the patient in prescribing parenteral this drug for chronic use, particularly if the drug is to be self-administered
- Severe sclerosis of the skin, subcutaneous tissues, and underlying muscle may occur at the injection sites of patients who have received multiple doses of this drug. Rotate injection sites constantly to avoid such manifestations
- Head injury and increased intracranial pressure may occur; such effects are markedly exaggerated in the presence of head injury, other intracranial lesions, or a preexisting increase in intracranial pressure. This drug may obscure the clinical course of patients with head injuries. Use this drug with extreme caution and only if its use is deemed essential in such patients
- Hallucinations (usually visual), disorientation, and confusion may occur in patients. Closely observe such patients and check their vital signs. Exercise caution during reinstitution of this drug as acute CNS manifestations may recur. Cautiously use alcohol in patients who are currently receiving pentazocine as potential for increased CNS depressant effects exists
- As sedation, dizziness, and occasional euphoria may occur warn ambulatory patients to avoid operating machinery, driving cars, or unnecessarily exposing themselves to hazards
- IV administration of pentazocine is associated with increasing systemic and pulmonary arterial pressure and systemic vascular resistance in patients with acute myocardial infarction
- Allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes may occur in susceptible individuals due to acetone sodium bisulfite present in multiple-dose vials
- Respiratory depression may occur in patients with bronchial asthma. Exercise caution and administer lower dosages in susceptible individuals
- Extensive liver disease may predispose to greater side effects (e.g., marked apprehension, anxiety, dizziness, sleepiness) from the usual clinical dose, and may occur due to decreased metabolism of the drug by the liver
- Pentazocine may differ from other marketed narcotics in their respect to elevate biliary tract pressure
- Patients previously given narcotics, including methadone for the daily treatment of narcotic dependence may experience withdrawal symptoms after receiving this drug
- Seizures may occur in susceptible patients in association with the use of this drug
- Concomitant use of CNS depressants with parenteral pentazocine may produce additive CNS depression. Keep adequate equipment and facilities available to identify and treat systemic emergencies
Cautions: Use cautiously in
- Renal impairment
- Hepatic impairment
- CV disease
- Patients with MI having nausea or vomiting
- Hypotension
- CNS depression
- Impaired pulmonary function
- Severe bronchial asthma
- Cor pulmonale
- Obstructive respiratory conditions
- Cyanosis
- Severe limited respiratory reserve
- Opioid dependence
- Head injury
- Increased ICP
- Seizure disorder
- Inflammatory bowel disease
- Obstructive GI disease
- Acute abdomen
- Biliary disease
- Pancreatitis
- Porphyria
- Prostatic hypertrophy
- Hypothyroidism
- Adrenal insufficiency
- Substance abuse
- Alcohol use
- Use of CNS depressants
- Debilitated patients
- Geriatrics
- Delirium tremens
Supplemental Patient Information
- Advise patients undergoing treatment to avoid driving a motor vehicle or operating machinery
- Instruct patients to avoid concomitant use of this drug with alcohol or other CNS depressants
Pregnancy Category:C
Breastfeeding: Since no information is available on the use of pentazocine during breastfeeding, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 27 April 2011).
