Pentazocine
TALWIN
Pronunciation: pen-TAZ-oe-seen
“Towel wins a Pentagram”
What it isKappa agonist and mu partial agonist; moderate pain.
Why this oneA ceiling on respiratory depression, and the oral form is combined with naloxone to deter injection.
What limits itDysphoria and hallucinations from kappa agonism, worst in the elderly. It precipitates withdrawal in the opioid-dependent.
FDA-approved for
- pain (~1967)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Pain | adult | 1 tablet q3-4h PRN | 1-2 tablets q3-4h PRN | 12 tablets/day |
Renal Undefined
Hepatic Undefined
Total daily dose should not exceed 12 tablets.
Instructions
- Use lowest effective dose for shortest duration
- Do not abruptly discontinue in physically dependent patients - taper by no more than 10-25% of daily dose every 2-4 weeks
- Ensure access to an opioid overdose reversal agent
Available strengths
- tab 50 mg
Contraindications
- Significant respiratory depression
- Acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment
- Known or suspected GI obstruction, including paralytic ileus
Cautions
- Life-threatening respiratory depression
- Addiction, abuse, and misuse
- Serotonin syndrome with concomitant serotonergic drugs
- Adrenal insufficiency
- Severe hypotension
- Seizures; may raise intracranial pressure
- Profound sedation/respiratory depression with benzodiazepines or other CNS depressants
Adverse reactions
- Nausea, vomiting, constipation
- Dizziness, lightheadedness, sedation, euphoria
- Hallucinations (usually visual), disorientation, confusion
- Sweating
- Hypertension, hypotension, tachycardia
- Visual blurring, miosis
Pregnancy Prolonged use can cause neonatal opioid withdrawal syndrome; no adequate human data - advise of potential fetal risk.
Lactation Excreted in human milk; use with caution and monitor infant for excess sedation/respiratory depression.
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 50 mg | tab | per unit | not offered |
⚠ BOXED WARNINGS
- Addiction, abuse and misuse
- Life-threatening respiratory depression
- Risk from concomitant use with benzodiazepines
Classes and tags
Clinical profile
Defining liabilityRespiratory depression, dependence and dysphoric CNS effects
Serotonin and MAOI
Provisional washout figures
Elevating mechanismWeak SRI
Evidence confidenceModerate
InterpretationInhibits 5-HT uptake in two matched series: rat brain synaptosomes (Mennini 1978, "much less activity" than levorphanol) and human platelets (Ahtee 1973, second only to methadone, ahead of pethidine). Weak and assay-dependent. Gillman: best avoided with MAOIs for uncertainty; unlikely to precipitate ST except in overdose.