Knowledge
Collections with the topic tag Buprenorphine
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A. Physiochemistry
- Semi-synthetic thebaine derivative (like oxycodone).
- Partial µ-agonist.
B. Pharmacokinetics
- Dose: 0.5 mg q6h IV/IM
- 30x morphine potency
- 200mcg-400mcg sublingual qid for analgesia
- Absorption - IV, IM, s/l, epidural (po undesirable as ++ 1st pass met)
- Distribution - 3 L/kg
- Protein binding - 96%
- Onset 30 min; Offset 4 h (longer latency & duration than morph)
- Metabolism - ß½ 5 h; hepatic dealkylation & glucuronidation. Excreted in bile & hydrolysed by GIT bacteria.
- Clearance - 14 mL/min/kg (dec 30% by GA)
C. Pharmacodynamics
- Mechanism: µ partial agonist.
- 50x greater mu rec affinity than morphine.
- May be used to treat heroin/morphine dependence.
- Greater lipid solubility than morphine.
- Ceiling effect to both analgesia & respiratory depression.
- Long duration as slow to dissociate from receptor & thus difficult to reverse.