BUVIDAL Prolonged-release solution for injection Ref.[6697] Active ingredients: Buprenorphine

Administration

Care must be taken to avoid inadvertent injection of Buvidal. The dose must not be administered intravascularly (intravenously), intramuscularly or intradermally.

Intravascular such as intravenous injection would present a risk of serious harm as Buvidal forms a solid mass upon contact with body fluids, which potentially could cause blood vessel injury, occlusion, or thromboembolic events.

To minimise the risk of misuse, abuse and diversion, appropriate precautions should be taken when prescribing and dispensing buprenorphine. Healthcare professionals should administer Buvidal directly to the patient. Take-home use or self-administration of the product by patients is not allowed. Any attempts to remove the depot should be monitored throughout treatment.

Prolonged-release properties

The prolonged-release properties of the product should be considered during treatment including initiation and termination. In particular, patients with concomitant medicinal products and/or comorbidities, should be monitored for signs and symptoms of toxicity, overdose or withdrawal caused by increased or decreased levels of buprenorphine.

For pharmacokinetic properties, see section 5.2 and for treatment termination, see section 4.2.

Respiratory depression

A number of cases of death due to respiratory depression have been reported for patients being treated with buprenorphine, particularly when used in combination with benzodiazepines (see section 4.5) or when buprenorphine was not used according to prescribing information. Deaths have also been reported in association with concomitant administration of buprenorphine and other depressants such as alcohol, gabapentinoids (such as pregabalin and gabapentin) (see section 4.5) or other opioids. Buprenorphine should be used with care in patients with respiratory insufficiency (e.g. chronic obstructive pulmonary disease, asthma, cor pulmonale, decreased respiratory reserve, hypoxia, hypercapnia, pre-existing respiratory depression or kyphoscoliosis).

Buprenorphine may cause severe, possibly fatal, respiratory depression in children and non-opioid dependent persons who accidentally or deliberately use it.

CNS depression

Buprenorphine may cause drowsiness particularly when taken together with alcohol or central nervous system depressants such as benzodiazepines, tranquilisers, sedatives, gabapentinoids or hypnotics (see sections 4.5 and 4.7).

Dependence

Buprenorphine is a partial agonist at the mu-opiate receptor and chronic administration can produce opioid dependence.

Serotonin syndrome

Concomitant administration of Buvidal and other serotonergic agents, such as MAO inhibitors, selective serotonin re-uptake inhibitors (SSRIs), serotonin norepinephrine re-uptake inhibitors (SNRIs) or tricyclic antidepressants may result in serotonin syndrome, a potentially life-threatening condition (see section 4.5). If concomitant treatment with other serotonergic agents is clinically warranted, careful observation of the patient is advised, particularly during treatment initiation and dose increases.

Symptoms of serotonin syndrome may include mental-status changes, autonomic instability, neuromuscular abnormalities, and/or gastrointestinal symptoms. If serotonin syndrome is suspected, a dose reduction or discontinuation of therapy should be considered depending on the severity of the symptoms.

Hepatitis and hepatic events

Baseline liver function tests and documentation of viral hepatitis status are recommended prior to starting therapy. Patients who are positive for viral hepatitis, on certain concomitant medicinal products (see section 4.5) and/or who have existing liver dysfunction are at greater risk of liver injury. Regular monitoring of the liver function is recommended.

Cases of acute hepatic injury have been reported in opioid-dependent patients both in clinical studies and in post-marketing adverse reaction reports with medicinal products containing buprenorphine. The spectrum of abnormalities ranges from transient asymptomatic elevations in hepatic transaminases to case reports of cytolytic hepatitis, hepatic failure, hepatic necrosis, hepatorenal syndrome, hepatic encephalopathy and death. In many cases, the presence of pre-existing liver enzyme abnormalities, genetic disease, infection with hepatitis B or hepatitis C virus, alcohol abuse, anorexia, concomitant use of other potentially hepatotoxic medicinal products and ongoing injecting drug use may have a causative or contributory role. These underlying factors must be taken into consideration before prescribing buprenorphine and during treatment. When a hepatic event is suspected, further biological and aetiological evaluation is required. Depending on the findings, Buvidal may be discontinued. Monitoring beyond the weekly and monthly treatment period may be needed. If treatment is continued, hepatic function should be monitored closely.

Precipitation of opioid withdrawal syndrome

When initiating treatment with buprenorphine, it is important to be aware of the partial agonist profile of buprenorphine. Buprenorphine products have caused precipitated withdrawal symptoms in opioiddependent patients when administered before the agonist effects resulting from recent opioid use or misuse have subsided. To avoid precipitated withdrawal, induction must be undertaken when objective signs and symptoms of mild to moderate withdrawal are evident (see section 4.2). Discontinuation of treatment may result in a withdrawal syndrome that may be delayed in onset.

Hepatic impairment

Buprenorphine is extensively metabolised in the liver. Patients with moderate hepatic impairment should be monitored for signs and symptoms of precipitated opioid withdrawal, toxicity or overdose caused by increased levels of buprenorphine. Buprenorphine should be used with caution in patients with moderate hepatic impairment (see sections 4.2 and 5.2). Hepatic function should be monitored regularly whilst on treatment. The use of buprenorphine is contraindicated in patients with severe hepatic impairment (see section 4.3).

Renal impairment

Metabolites of buprenorphine accumulate in patients with renal failure. Caution is recommended when dosing patients with severe renal impairment (creatinine clearance <30 ml/min), see sections 4.2 and 5.2.

QT prolongation

Caution should be exercised when co-administering Buvidal with other medicinal products that prolong the QT interval and in patients with a history of long QT syndrome or other risk factors for QT prolongation.

Acute pain management

For management of acute pain during continued use of Buvidal, a combination of use of opioids with high mu-opioid receptor affinity (e.g. fentanyl), non-opioid analgesics and regional anaesthesia might be necessary. Titration of oral or intravenous short-acting opioid pain medicinal products (immediaterelease morphine, oxycodone or fentanyl) to the desired analgesic effect in patients treated with Buvidal might require higher doses. Patients should be monitored during treatment.

Use in children and adolescents

The safety and efficacy of buprenorphine in children below the age of 16 years have not been established (see section 4.2). Due to limited data in adolescents (aged 16 or 17 years), patients in this age group should be monitored closely during treatment.

Sleep-related breathing disorders

Opioids can cause sleep-related breathing disorders including central sleep apnoea (CSA) and sleeprelated hypoxemia. Opioid use increases the risk of CSA in a dose-dependent fashion. In patients who present with CSA, consider decreasing the total opioid dosage.

Class effects

Opioids may cause orthostatic hypotension.

Opioids may elevate cerebrospinal fluid pressure, which may cause seizures. Therefore, opioids should be used with caution in patients with head injury, intracranial lesions, other circumstances where cerebrospinal pressure may be increased, or history of seizure.

Opioids should be used with caution in patients with hypotension, prostatic hypertrophy or urethral stenosis.

Opioid-induced miosis, changes in the level of consciousness or changes in the perception of pain as a symptom of disease may interfere with patient evaluation or obscure the diagnosis or clinical course of concomitant disease.

Opioids should be used with caution in patients with myxoedema, hypothyroidism, or adrenal cortical insufficiency (e.g. Addison’s disease).

Opioids have been shown to increase intracholedochal pressure, and should be used with caution in patients with dysfunction of the biliary tract.

No interaction studies have been performed with Buvidal.

Buprenorphine should be used cautiously when co-administered with:

• benzodiazepines: This combination may result in death due to respiratory depression of central origin. Therefore, dosages must be closely monitored and this combination must be avoided in cases where there is a risk of misuse. Patients should be warned that it is extremely dangerous to self-administer non-prescribed benzodiazepines whilst taking this product, and should also be cautioned to use benzodiazepines concurrently with this product only as directed by their physician (see section 4.4).
• gabapentinoids: This combination may result in death due to respiratory depression. Therefore, dosages must be closely monitored and this combination must be avoided in cases where there is a risk of misuse. Patients should be cautioned to use gabapentinoids (such as pregabalin and gabapentin) concurrently with this product only as directed by their physician (see section 4.4).
• alcoholic drinks or medicinal products containing alcohol as alcohol increases the sedative effect of buprenorphine (see section 4.7).
• other central nervous system depressants: Other opioid derivatives (e.g. methadone, analgesics and antitussives); certain antidepressants, sedative H1-receptor antagonists, barbiturates, anxiolytics other than benzodiazepines, antipsychotics, clonidine and related substances. These combinations increase central nervous system depression. The reduced level of alertness can make driving and using machinery hazardous (see section 4.7).
• opioid analgesics: Adequate analgesia may be difficult to achieve when administering a full opioid agonist in patients receiving buprenorphine. The potential for overdose also exists with a full agonist, especially when attempting to overcome buprenorphine partial agonist effects, or when buprenorphine plasma levels are declining (see section 4.4)
• naltrexone and nalmefene: These are opioid antagonists that can block the pharmacological effects of buprenorphine. For opioid-dependent patients currently receiving buprenorphine treatment, naltrexone may precipitate a sudden onset of prolonged and intense opioid withdrawal symptoms. For patients currently receiving naltrexone treatment, the intended therapeutic effects of buprenorphine administration may be blocked by naltrexone.
• Buprenorphine is metabolised to norbuprenorphine primarily by CYP3A4. The effects on buprenorphine exposure in patients treated with Buvidal have not been studied. Interaction with co-administered inducers or inhibitors have been established in studies using transmucosal and transdermal buprenorphine. Buprenorphine is also metabolised to buprenorphine-3-glucuronide by UGT1A1.
  • CYP3A4 inhibitors may inhibit the metabolism of buprenorphine resulting in increased C_max and AUC of buprenorphine and norbuprenorphine. Buvidal avoids first-pass effects and CYP3A4 inhibitors (e.g. protease inhibitors like ritonavir, nelfinavir or indinavir, or azole antifungals such as ketoconazole or itraconazole, or macrolide antibiotics) are expected to have less effects on buprenorphine metabolism when co-administered with Buvidal as compared to when co-administered with sublingual buprenorphine. When switching from sublingual buprenorphine to Buvidal, patients may need to be monitored to ensure plasma buprenorphine levels are adequate. Patients already on Buvidal who start treatment with CYP3A4 inhibitors should be treated with weekly Buvidal and be monitored for signs and symptoms of overtreatment. Conversely, if a patient who is concomitantly treated with Buvidal and a CYP3A4 inhibitor stops treatment with the CYP3A4 inhibitor, the patient should be monitored for symptoms of withdrawal.
  • CYP3A4 inducers may induce the metabolism of buprenorphine resulting in decreased buprenorphine levels. Buvidal avoids first-pass effects and CYP3A4 inducers (e.g. phenobarbital, carbamazepine, phenytoin or rifampicin) are expected to have less effects on buprenorphine metabolism when co-administered with Buvidal as compared to when co-administered with sublingual buprenorphine. When switching from sublingual buprenorphine to Buvidal, patients may need to be monitored to ensure plasma buprenorphine levels are adequate. Patients already on Buvidal who start treatment with CYP3A4 inducers should be treated with weekly Buvidal and be monitored for signs and symptoms of withdrawal. Conversely, if a patient who is concomitantly treated with Buvidal and a CYP3A4 inducer stops treatment with the CYP3A4 inducer, the patient should be monitored for symptoms of overtreatment.
  • UGT1A1 inhibitors may affect the systemic exposure of buprenorphine.
• monoamine oxidase inhibitors (MAOI): Possible exacerbation of the opioids effects, based on experience with morphine.
• Serotonergic medicinal products, such as MAO inhibitors, selective serotonin re-uptake inhibitors (SSRIs), serotonin norepinephrine re-uptake inhibitors (SNRIs) or tricyclic antidepressants as the risk of serotonin syndrome, a potentially life-threatening condition, is increased (see section 4.4).

Pregnancy

There are no or limited data from the use of buprenorphine in pregnant women. Animal studies do not indicate reproductive toxicity (see section 5.3). Buprenorphine should be used during pregnancy only if the potential benefit outweighs the potential risk to the foetus.

Towards the end of pregnancy, buprenorphine may induce respiratory depression in the newborn infant even after a short period of administration. Long-term administration during the last three months of pregnancy may cause a withdrawal syndrome in the neonate (e.g. hypertonia, neonatal tremor, neonatal agitation, myoclonus or convulsions). The syndrome is generally delayed from several hours to several days after birth.

Due to the long half-life of buprenorphine, neonatal monitoring for several days after birth should be considered to prevent the risk of respiratory depression or withdrawal syndrome in neonates.

Breast-feeding

Buprenorphine and its metabolites are excreted in human breast milk and Buvidal should be used with caution during breast-feeding.

Fertility

There are no or limited data on effects of buprenorphine on human fertility. An effect of buprenorphine on fertility in animals has not been seen (see section 5.3).

Buprenorphine has minor to moderate influence on the ability to drive and use machines when administered to opioid-dependent patients. Buprenorphine may cause drowsiness, dizziness or impaired thinking, especially during treatment induction and dose adjustment. If used together with alcohol or central nervous system depressants, the effect is likely to be more pronounced (see sections 4.4. and 4.5).

The patient should be cautioned not to drive or operate hazardous machinery whilst taking this medicine until it is known how the patient is affected by the medicine. An individual recommendation should be given by the treating healthcare professional.

Summary of the safety profile

The adverse reactions most frequently reported for buprenorphine are headache, nausea, hyperhidrosis, insomnia, drug withdrawal syndrome and pain.

Tabulated list of adverse reactions

Table 2 presents adverse reactions reported for buprenorphine, including Buvidal. The following terms and frequencies are applied: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1000 to <1/100) and frequency not known (cannot be estimated from available data).

Table 2. Adverse reactions listed by body system:

Description of selected adverse reactions

Injection site reactions

In the double-blind, phase 3 efficacy trial, injection site-related adverse reactions were observed in 36 (16.9%) of the 213 patients (5% of the administered injections) in the Buvidal treatment group. The most common adverse reactions were injection site pain (8.9%), injection site pruritus (6.1%) and injection site erythema (4.7%). The injection site reactions were all mild or moderate in severity and most events were transient.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medical product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system listed in Appendix V.

This medicinal product must not be mixed with other medicinal products.