Special Warning : אזהרת שימוש

4.4    Special warnings and precautions for use
Severe acute exacerbations of chronic hepatitis B are relatively frequent, and are characterised by transient elevation of serum ALT. Following initiation of antiviral treatment, serum ALT may rise in some patients while serum levels of HBV DNA fall (see section 4.8).
On average, 4-5 weeks elapsed prior to the occurrence of an exacerbation in patients treated with telbivudine. Overall, ALT flares occurred more frequently in HBeAg-positive patients than in HBeAg-negative patients. In patients with compensated liver disease, this elevation of serum ALT is generally not accompanied by elevated levels of serum bilirubin or by other signs of hepatic decompensation. The risk of hepatic decompensation – and of a subsequent exacerbation of hepatitis – may be elevated in patients with cirrhosis. Such patients should therefore be closely monitored.
Exacerbations of hepatitis have also been reported in patients who have terminated treatment of hepatitis B. Post-treatment ALT flares are normally associated with increases in serum HBV DNA levels, and the majority of such cases have proven to be self-limiting.
Nonetheless, there have also been reports of severe – and sometimes fatal – post-treatment disease exacerbations. Therefore, hepatic function should be monitored at regular intervals with both clinical and laboratory follow-up for at least 6 months after discontinuation of hepatitis B therapy.



Lactic acidosis
Rare post-marketing cases of lactic acidosis have been reported with telbivudine. Cases were SEB API AUG17 CL V7                                         REF EMA SmPC 23Jun2017 more often secondary to other serious conditions (e.g. rhabdomyolysis) and/or associated muscle-related events (e.g. myopathy, myositis). When secondary to other conditions, some cases were also associated with pancreatitis, liver failure/hepatic steatosis and renal failure. In some cases, fatal outcomes were reported when lactic acidosis was secondary to rhabdomyolysis. Patients should be followed closely.
Treatment with telbivudine should be discontinued when metabolic/lactic acidosis of unknown aetiology occurs. Benign digestive symptoms, such as nausea, vomiting and abdominal pain, may be indicative of lactic acidosis development.


Muscular effects
Cases of myopathy and myalgia have been reported with telbivudine use several weeks to months after starting therapy (see section 4.8). Cases of rhabdomyolysis have been reported during post-marketing use of telbivudine (see section 4.8).
Myopathy, defined as persistent unexplained muscle aches and/or muscle weakness regardless of the degree of increases in creatine kinase (CK) levels, should be considered in any patient with diffuse unexplained myalgias, muscle tenderness , muscle weakness or myositis (defined as myopathy with histological evidence of muscle damage). Patients should be advised to report promptly any persistent unexplained muscle aches, pain, tenderness or weakness. If any of these symptoms are reported, a detailed muscle examination should be performed in order to evaluate muscle function. Telbivudine therapy should be discontinued if myopathy is diagnosed.
It is not known whether the risk of myopathy during treatment with telbivudine is increased with concurrent administration of other medicinal products associated with myopathy (e.g.
statins, fibrates, or ciclosporin). Physicians considering concomitant treatment with other agents associated with myopathy should weigh carefully the potential benefits and risks and should monitor patients for any signs or symptoms suggestive of myopathy.
Peripheral neuropathy
Peripheral neuropathy has been uncommonly reported in telbivudine-treated patients. If peripheral neuropathy is suspected, treatment with telbivudine should be reconsidered (see section 4.8).
An increased risk of developing peripheral neuropathy has been observed in one study when telbivudine and pegylated interferon alfa-2a were co-administered (see section 4.5). Such increased risk cannot be excluded for other interferon alfa (pegylated or standard). Moreover, the benefit of the combination of telbivudine with interferon alfa (pegylated or standard) is not currently established.
Therefore, the combination of telbivudine with pegylated or standard interferon alfa is contraindicated (see section 4.3).


Renal function
SEB API AUG17 CL V7                                          REF EMA SmPC 23Jun2017 Telbivudine is eliminated primarily by renal excretion, therefore dose interval adjustment is recommended in patients with creatinine clearance <50 mL/min, including patients on haemodialysis. The effectiveness of dosing interval adjustment has not been clinically evaluated. Therefore, virological response should be closely monitored in patients with increased dosage interval (see sections 4.2 and 5.2).


Patients with cirrhosis without decompensation
Due to the limited data available (about 3% of patients enrolled had cirrhosis), telbivudine should be used with particular caution in cirrhotic patients. These patients should be closely monitored for clinical, biochemical and virological parameters associated with hepatitis B during treatment and after treatment is discontinued.

Patients with cirrhosis with decompensation

There are no adequate efficacy and safety data in patients with decompensated cirrhosis.
Sebivo is not indicated in patients with decompensated cirrhosis.
Patients with previous exposure to nucleoside/nucleotide analogues
In vitro, telbivudine was not active against the HBV strains containing rtM204V/rtL180M or rtM204I mutations (see section 5.1). Telbivudine monotherapy is not an option for patients with established lamivudine-resistant hepatitis B virus infection. Patients who failed to achieve virological response following treatment with lamivudine for more than 24 weeks are unlikely to benefit from telbivudine monotherapy. There is currently no clinical data to properly assess the benefit and risk of switching to telbivudine for lamivudine-treated patients who achieve complete viral suppression on lamivudine.
There are no data on telbivudine treatment in patients with established adefovir-resistant hepatitis B virus single mutations of rtN236T or A181V. Results from cell-based assays showed that the adefovir resistance-associated substitution A181V had 1.5- to approximately 4-fold reduced susceptibility to telbivudine.

Liver transplant recipients
The safety and efficacy of telbivudine in liver transplant recipients are unknown.



Elderly

SEB API AUG17 CL V7                                        REF EMA SmPC 23Jun2017 Clinical studies of telbivudine did not include sufficient numbers of patients  65 years of age to determine whether they respond differently from younger subjects. In general, caution must be exercised when prescribing Sebivo to older patients in view of the greater frequency of decreased renal function due to concomitant disease or concomitant use of other medicinal products.
Other Special populations
Sebivo has not been investigated in co-infected hepatitis B patients (e.g. patients co-infected with human immunodeficiency virus [HIV], hepatitis C virus [HCV] or hepatitis D virus [HDV]).


General
Patients should be advised that treatment with Sebivo has not been shown to reduce the risk of transmission of HBV to others through sexual contact or blood contamination.
Telbivudine is not recommended to be used with lamivudine because in a phase II study, the treatment response observed with combination therapy of telbivudine and lamivudine was lower than with telbivudine alone.

There are currently no efficacy and safety data for other antiviral combinations with telbivudine.

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