Talwin

Action

Unknown. Thought to interact with opioid receptor sites primarily in limbic system, thalamus, and spinal cord, blocking transmission of pain impulses.

Availability

Injection: 30 mg/ml (as lactate salt) Tablets: 50 mg pentazocine and 0.5 mg naloxone (Talwin NX); 25 mg pentazocine and 650 mg acetaminophen (Talacen)

Indications and dosages

➣ Moderate to severe pain; preoperative or preanesthetic medication; adjunct to surgical anesthesia

Adults: 30 mg subcutaneously, I.M., or I.V. q 3 to 4 hours (not to exceed 60 mg/dose subcutaneously or I.M., or 30 mg/dose I.V.). Maximum daily dosage is 360 mg.

➣ Moderate to severe pain

Adults: Initially, one tablet (Talwin Nx) q 3 to 4 hours, increased to two tablets p.r.n., up to a maximum of 12 tablets daily

➣ Mild to moderate pain

Adults: One tablet (Talacen) P.O. q 4 hours; up to a maximum of six tablets daily

➣ Labor

Adults: 20 mg I.V. for two or three doses at 2- to 3-hour intervals, or 30 mg I.M. as a single dose

Contraindications

• Hypersensitivity to drug, acetaminophen, or naloxone (with oral form)

Precautions

Use cautiously in:

• head trauma, increased intracranial pressure, respiratory conditions, adrenal insufficiency, seizure disorder, acute CNS manifestations, hepatic impairment, acute myocardial infarction, alcohol or narcotic use

• sulfite sensitivity (Talacen)

• history of drug abuse

• pregnant or breastfeeding patients

• children (safety not established).

Administration

• Administer each 5-mg I.V. dose by slow direct infusion over 1 minute, with patient lying supine.

• Use subcutaneous route only when necessary (may cause tissue damage).

Adverse reactions

CNS: dizziness, drowsiness, euphoria, hallucinations, headache, sedation, dysphoria, insomnia, unusual dreams, weakness, depression, irritability, excitement, tremor, paresthesia

CV: hypertension, hypotension, syncope, tachycardia, circulatory depression, shock

EENT: blurred vision, diplopia, nystagmus, miosis (with high doses), tinnitus

GI: nausea, vomiting, constipation, diarrhea, dry mouth, ileus, cramps, abdominal distress, anorexia

GU: urinary retention, altered rate and strength of labor contractions Hematologic: thrombocytopenia purpura (with Talacen)

Respiratory: dyspnea, transient apnea in neonates whose mothers received pentazocine during labor, respiratory depression

Skin: clammy skin, diaphoresis, rash, urticaria, nodules, cutaneous depression, skin and subcutaneous sclerosis, dermatitis, pruritus, flushing

Other: altered taste, chills, soft-tissue induration, stinging on injection, facial edema, physical or psychological drug dependence, drug tolerance, anaphylaxis

Interactions

Drug-drug. Barbiturates, first-generation (sedating) antihistamines, other sedating drugs: additive CNS depression

MAO inhibitors: unpredictable reactions

Opioids: decreased analgesic effects

Drug-diagnostic tests. Amylase, lipase: increased levels

Granulocytes, white blood cells: reduced counts

Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

☞ Monitor vital signs. Watch closely for evidence of shock, dyspnea, and circulatory or respiratory depression.

• Monitor drug efficacy.

• In prolonged use, assess for signs and symptoms of drug dependence.

Patient teaching

☞ Tell patient receiving Talacen or Talwin NX that drug is for oral use only. Life-threatening reactions may result from misusing drug by injection.

• Inform patient that withdrawal symptoms may occur if he stops taking drug suddenly after prolonged use.

• Urge patient to avoid alcohol.

• Advise patient to consult prescriber before taking other prescription drugs or over-the-counter preparations.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects him.

• Advise patient to have periodic eye exams.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.