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pentazocine (Talwin)

Tradename: Talwin. DEA-controlled substance: class 4. Dosage: 1) 30 mg IV/IM every 3-4 hours 2) 50 mg PO every 4-6 hours PRN (also contains naloxone 0.5 mg) Tabs: 50 mg. Pharmacokinetics: 1) extensive 1st pass metabolism in liver 2) 3-15% excreted unchanged in the urine 3) racemic mixture; L-isomer is analgesic form Adverse effects: 1) sedation 2) sweating 3) dizziness 4) nausea 5) psychometric effects 6) autonomic crisis (at high doses) a) respiratory depression b) tachycardia c) hypertension 7) may result in immediate withdrawal symptoms in opiate- dependent patients [3] 8) high incidence of delirium in elderly patients [3] Laboratory: 1) specimen: serum, plasma (EDTA), urine 2) methods: GLC, GC-MS, fluorometry, RIA 3) interferences: a) metabolites interfere with fluorometric assay b) acid hydrolysis modifies structure; deconjugation must be performed enzymatically

Interactions

drug interactions drug adverse effects (more general classes)

General

mixed opioid agonist-antagonist (analgesic narcotic partial-mixed agonist)

Properties

INHIBITS: opiate MISC-INFO: elimination route LIVER 1/2life 2-7 HOURS therapeutic-range 50-200 NG/ML toxic-range >1000 NG/ML protein-binding 60-70% elimination by hemodialysis + pregnancy-category C safety in lactation ?

Database Correlations

PUBCHEM correlations

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
  2. Clinical Guide to Laboratory Tests, 3rd ed. Teitz ed., W.B. Saunders, 1995
  3. Geriatrics Review Syllabus, American Geriatrics Society, 5th edition, 2002-2004

Component-of

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