pentazocine (Talwin)

Introduction

Tradename: Talwin. DEA-controlled substance: class 4.

Dosage

• 30 mg IV/IM every 3-4 hours
• 50 mg PO every 4-6 hours PRN (also contains naloxone 0.5 mg)

Tabs: 50 mg.

Pharmacokinetics

• extensive 1st pass metabolism in liver
• 3-15% excreted unchanged in the urine
• racemic mixture; L-isomer is analgesic form

elimination via liver

1/2life = 2-7 hours

protein binding = 60-70 %

elimination by hemodialysis = +

Adverse effects

• sedation
• sweating
• dizziness
• nausea
• psychometric effects
• autonomic crisis (at high doses)
  • respiratory depression
  • tachycardia
  • hypertension
• may result in immediate withdrawal symptoms in opiate- dependent patients
• high incidence of delirium in elderly patients

• drug adverse effects of opiates
• drug adverse effects of psychotropic agents
• drug adverse effects of sedatives

Laboratory

• specimen: serum, plasma (EDTA), urine
• methods: GLC, GC-MS, fluorometry, RIA
• interferences:
  • metabolites interfere with fluorometric assay
  • acid hydrolysis modifies structure; deconjugation must be performed enzymatically

More general terms

• mixed opioid agonist-antagonist

Component of

• acetaminophen/pentazocine (Talacen)
• naloxone/pentazocine (Talwin NX)
• aspirin/pentazocine (Talwin Compound)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=4736
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=441278
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=9669
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=198520
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=107799
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=656697
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=441277
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=66386