Buprenorphine
Mechanism of action: partial agonist activity at mu-opioid receptors, antagonist at kappa-opioid receptors
At high doses (4-32mg sublingual tablet) it is used as opioid substitution therapy (OST) for drug dependence
Presentation: sublingual tablet, transdermal patch (varying dose and duration) – patches are restricted for use on recommendation of palliative care or pain team only. Do not apply more than one patch at a time: using more than one patch could result in a fatal overdose. Make sure the old patch is removed before the new patch is put on.
Suggested dose: OST dose determined by community addictions service. Continue usual dose while in hospital but it must be given in two or three divided doses [Withdrawal Prevention Algorithm]
Co-prescribe prn Naloxone
Oral absorption: Very low oral bioavailability due to extensive first pass metabolism. Sublingual tablets have approx. 30% bioavailability
Protein binding: 96% protein bound to alpha- and beta-globulin
Metabolism: Hepatic. Metabolised by CYP3A4 to norbuprenorphine.
Elimination: mainly via faeces, with 10-30% excreted in urine
Half-life: sublingual 37 hours
Further prescribing information (side effects, contraindications, interactions):