Pentazocine Lactate

Pronunciation: pen-TAZ-oh-seen lak-tate
Class: Opioid agonist-antagonist analgesic

Trade Names

Talwin
- Injection 30 mg/mL

Pharmacology

Produces analgesia by an agonistic effect at the kappa opioid receptor. Weakly antagonizes effects of opiates at mu opioid receptor.

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Pharmacokinetics

Distribution

Moderate protein binding. Passes into fetal circulation.

Metabolism

Hepatic.

Elimination

Excreted primarily by the kidney. Half-life is 2 to 3 h.

Onset

IM/subcutaneous is 15 to 20 min; IV is 2 to 3 min.

Special Populations

No data available.

No data available.

Longer mean elimination half-life, lower mean total plasma Cl, and a larger mean AUC.

No data available.

Indications and Usage

Management of moderate to severe pain; preoperative or preanesthetic medication; supplement to surgical anesthesia.

Contraindications

Standard considerations.

Dosage and Administration

IM 30 mg as single dose; alternatively, when contractions are regular, IV 20 mg for 2 to 3 doses given every 2 to 3 h.

IM / subcutaneous / IV 30 mg every 3 to 4 h (max, 360 mg/day). Doses greater than 30 mg IV or 60 mg subcutaneous/IM are not recommended.

IM 0.5 mg/kg single dose.

General Advice

• For IM administration, inject deep into well-developed tissue.
• For IV administration, inject undiluted by slow bolus. Do not exceed a 30 mg dose.
• Administer subcutaneously only when necessary; severe tissue damage is possible at injection sites.
• Do not mix in the same syringe with barbiturates; precipitation will occur.
• Constantly rotate injection sites.

Storage/Stability

Store at 59° to 86°F.

Drug Interactions

Causes additive CNS depression. Use with caution.

Causes increased CNS and respiratory depression.

Adverse Reactions

Cardiovascular

Circulatory depression, hypertension, shock, tachycardia.

CNS

Confusion, depression, disorientation, disturbed dreams, dizziness, euphoria, excitement, faintness, hallucinations, headache, insomnia, irritability, light-headedness, muscle tremor, paresthesia, sedation, syncope, tremor, weakness.

Dermatologic

Dermatitis, including pruritus; diaphoresis; flushed skin, including plethora.

EENT

Diplopia, miosis, nystagmus, tinnitus, visual blurring and focusing difficultly.

GI

Constipation, cramps, diarrhea, dry mouth, nausea, taste alteration, vomiting.

Hematologic

Eosinophilia, granulocytopenia.

Local

Cutaneous depression, nodules, severe sclerosis, soft tissue induration, sting on injection, and ulceration at injection sites.

Respiratory

Dyspnea, respiratory depression, transient apnea in newborns whose mothers received parenteral pentazocine during labor.

Miscellaneous

Allergic reactions (eg, edema of the face, toxic epidermal necrolysis), alterations in rate or strength of uterine contractions during labor, chills, urinary retention.

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established in children younger than 1 yr of age.

Elderly

May be more sensitive to the analgesic effects. Use low doses and observe these patients closely for confusion and oversedation.

Labor and Delivery

Use drug with caution in women delivering premature infants.

Special Risk Patients

Use with caution in patients with acute MI accompanied by asthma, cyanosis, decreased respiratory reserve, head injury, hypertension or left ventricular failure, increased intracranial pressure, obstructive pulmonary condition, respiratory depression, or seizure.

Sulfite Sensitivity

Drug may cause allergic-type reactions (eg, anaphylaxis, hives, itching, wheezing) in susceptible persons.

Abuse/Dependence/Withdrawal

Abuse potential exists. Abrupt discontinuation after long-term use may cause withdrawal symptoms. Do not substitute other opiates in pentazocine withdrawal syndrome. Pentazocine may induce withdrawal symptoms in narcotic-dependent patients.

Acute CNS manifestations

Confusion, disorientation, hallucinations, and seizures.

Biliary surgery

May elevate biliary tract pressure.

Renal or hepatic function impairment

Duration of action may be prolonged; dosage reduction may be required.

Tissue damage

Severe sclerosis of skin, subcutaneous tissues, and underlying muscle have occurred at injection sites.

Overdosage

Symptoms

Hypertension, respiratory depression, tachycardia.

Patient Information

• Caution patient not to stop taking drug abruptly without consulting health care provider.
• Advise patient to avoid sudden position changes to prevent orthostatic hypotension.
• Instruct patient to avoid intake of alcoholic beverages or other CNS depressants.
• Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness.

Copyright © 2009 Wolters Kluwer Health.