New drug: buprenorphine (Buvidal) prolonged-release solution for injection
Buprenorphine has been long-established as an opioid substitution medication available as sublingual tablets. It is an opioid partial agonist/antagonist with strong receptor binding affinity and it works by reducing the pleasurable effect of other opioids whilst preventing the withdrawal symptoms.
Buvidal is a new licensed presentation which is a prolonged-release injection so patients would only require weekly or monthly injections, in place of daily doses of tablets.
It is available as a pre-filled syringe containing:
- 8mg, 16mg, 24mg or 32mg for weekly administration
- 64mg, 96mg or 128mg for monthly administration
A test-dose of sublingual buprenorphine 4mg should be administered to patients who have not had a previous dose to evaluate tolerability prior to using Buvidal. The monthly injections should be initiated once the dose of the weekly injections has been stabilised.
According to NICE, Buvidal could be useful in certain circumstances such as where there is a risk of diversion, difficulty with treatment compliance, or if there are concerns about medicine security.
In prisons, there is a risk of medicine diversion, where the prescribed drug is transferred to another person for illicit use. Supervised consumption helps to minimise this risk but it is time-consuming and challenging to manage. The use of a long-acting injection would remove these risks and also facilitate safer and more effective treatment.
In the community, people can have difficulty attending clinics or pharmacies to obtain their daily supervised doses, particularly if they work, study, or have other commitments or reasons for not being able to attend. If they are given buprenorphine tablets to keep in possession, then this can lead to diversion, non-adherence to treatment, or children may be able to access it, which risks poisoning.
The most common side effects of Buvidal include injection site pain (8.9%), headache (7.5%), constipation (7.5%), nausea (7%), injection site pruritus (6.1%) and erythema (5.6%), and insomnia (5.6%). The tablets have less risk of insomnia (2.8%), but otherwise the side effect profile was similar.
The longevity of action of Buvidal can also result in prolonged duration of adverse effects and this could be particularly problematic with an overdose. Also, if the patient chose to have detoxification treatment then this would need to be delayed until the therapeutic effect wore off.
For further information, including resource implications, see NICE guidance [ES19].