Buprenorphine
Class: analgesic – opioid, partial mu agonist/weak kappa antagonist (partial agonist so ceiling effect to analgesia occurs)
Indications: moderate to severe pain
Contraindications/cautions: buprenorphine hypersensitivity/allergy, use with other opioids, adverse effects such as respiratory depression may not completely respond to naloxone, COPD, use with benzodiazepines; caution with MAOIs, hypotension, obstructive bowel disorders, hepatic impairment, renal impairment
Adverse reactions: see morphine
Metabolism/clearance: metabolised by unclear pathway
Interactions:
- additive CNS depression with other CNS depressants e.g. benzodiazepines (e.g. lorazepam), phenothiazines (e.g. chlorpromazine), tricyclic antidepressants (e.g. amitriptyline), other opioids, alcohol, baclofen, clobazam, clarithromycin
| Dosing: | |
|---|---|
| sublingual combo: | not used |
| subcut: | not used |
| patch: | 5 to 20 micrograms/hour (each patch lasts for 3 to 7 days depending on brand). Start on 5 micrograms patch; increase if required every 3 days |
Syringe driver: compatibility unknown so best to infuse on its own. Irritancy potential is unknown
Mechanism of action: partially stimulates mu- and blocks kappa opioid receptors in the CNS and gastrointestinal tract
Peak effect: patch: 60 hours after initial application
Onset: 11 to 21 hours
Duration: patch: 3 to 7 days – depending on brand
Notes:
- as buprenorphine is only a partial agonist of mu receptors and an antagonist of kappa receptors it should not be used with other opioids or within 24 hours of them as it may lead to severe opioid withdrawal
- as concentrations occur at 60 hours do not use in rapidly escalating pain
- for acute toxicity give naloxone 2 mg and repeat as required (max 10 mg) over a prolonged time but be aware that full reversal of toxicity may not occur as buprenorphine binding to opioid receptors is high
- do not cut patches. Apply patch to clean, dry skin – not to broken skin and not to a hairy area
- avoid exposing the patch to heat such as heating pads, hot water bath or shower
- equivalence to other opioid data are sparse but 20 micrograms/hour patch may be equivalent to 90 mg oral morphine per day
- it is recommended that no more than 2 patches be applied at the same time regardless of the patch strength
- a new patch should not ne applied to the same skin site for the subsequent 3 to 4 weeks