Buprenorphine in liver disease
With regard to use of LAIB in liver disease depot buprenorphine provides consistently higher serum concentrations of buprenorphine compared to sublingual dosing the following should be understood.
• Depot BPN levels cannot be rapidly decreased
• Contra-indications to depot buprenorphine includes Child-Pugh C hepatic impairment
• Use lower initial dose of depot BPN in hepatic impairment
• Extended use of pre-induction sublingual buprenorphine (3 months)
• Regular monitoring during treatment including LFTs fortnightly then 3-6 monthly after stabilization
Severe hepatic impairment more than doubles total buprenorphine levels after a single dose of buprenorphine. Moderate hepatic impairment causes buprenorphine levels to rise by a factor of 1.6 after a single exposure to buprenorphine (18)
Buprenorphine in renal disease
Renal elimination plays a relatively small role in the overall clearance of buprenorphine, therefore no dose modification based on renal function is generally required. However, metabolites of buprenorphine can accumulate in patients with renal failure, therefore caution is recommended when dosing patients with severe renal impairment (creatinine clearance < 30 ml/min).
Pregnancy and lactation
Both Buvidal and Sublocade are listed as Category C according to the TGA. Their use is therefore cautioned and the decision to prescribe or administer should only be made after a determination that the benefits of use outweigh the risks of use. LAIB is considered safe in lactation, because although buprenorphine may accumulate in breast milk, it is poorly absorbed into the baby's systemic circulation because of a significant hepatic first pass effect.
Depot buprenorphine provides consistently higher serum concentrations of buprenorphine compared to sublingual dosing. There concerns regarding Q-T prolongation, which although rare in the context of buprenorphine use, merit maintenance sublingual buprenorphine or the use of weekly Buvidal pending specialist cardiac assessment.
If a patient experiences acute nociceptive pain, then they should be managed as opioid tolerant. This may entail the following multimodal analgesia. Additional opioids may be used with caution subject to expert advice. If additional opioids are to be used then opioids with a low inhibitory constant (Ki) otherwise known as "opioid super agonists", can be considered. These opioids can compete with buprenorphine for mu-receptor occupancy. These include hydromorphone fentanyl or morphine.
If patients present intoxicated, the frequency of clinical review needs to be reconsidered. However, because both LAIB products have delayed T-maxes, there is little clinical indication to withhold a depo injection due to a patient presenting intoxicated. This is in contrast to intoxicated patients presenting for sublingual buprenorphine or methadone dosing, where peak medication effects are likely to occur whilst the patient remains intoxicated.