Zeffix Adverse Reactions

Clinical Trial Data: In clinical studies of patients with chronic hepatitis B, ZEFFIX was well tolerated. The incidence of adverse events and laboratory abnormalities (with the exception of elevations of ALT and CPK, see as follows) were similar between placebo and ZEFFIX treated patients (see Table 2). The most common adverse events reported were malaise and fatigue, respiratory tract infections, headache, abdominal discomfort and pain, nausea, vomiting and diarrhoea. (See Table 2.)

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Adverse reactions are listed as follows by system organ class and frequency. Frequency categories are only assigned to those adverse reactions considered to be at least possibly causally related to ZEFFIX. Frequencies are defined as: very common (≥1/10), common (≥1/100, <1/10), uncommon (≥1/1000, <1/100), rare (≥1/10,000, <1/1000) and very rare (<1/10,000).
The frequency categories assigned to the adverse reactions as follows are estimates: for most events, suitable data for calculating incidence are not available. Very common and common adverse drug reaction frequency categories were determined from clinical trial data and the background incidence in placebo groups was not taken into account. Adverse drug reactions identified through post-marketing surveillance were categorised as rare or very rare.
Hepatobiliary disorders: Very common: Elevations of ALT.
Elevations in ALT were more common post-treatment in patients treated with ZEFFIX than placebo. In controlled trials in patients with compensated liver disease, however, there was no appreciable difference post-treatment in clinically severe ALT elevations associated with bilirubin elevations and/or signs of hepatic insufficiency, between ZEFFIX and placebo treated patients. The relationship of these recurrent hepatitis events to ZEFFIX treatment or to the previous underlying disease is uncertain (see Precautions).
Skin and subcutaneous tissue disorder: Common: Rash.
Musculoskeletal and connective tissue disorders: Common: Elevations of CPK.
Post-Marketing Data: In addition to adverse events reported from clinical trials, the following events have been identified during post-approval use of ZEFFIX.
Blood and lymphatic system disorders: Very rare: Thrombocytopenia.
Musculoskeletal and connective tissue disorders: Common: Muscle disorders, including myalgia and cramps. Very rare: Rhabdomyolysis.
In patients with HIV infection, cases of pancreatitis and peripheral neuropathy (or paraesthesia) have been reported, although no relationship to treatment with lamivudine (EPIVIR) has been clearly established. In patients with chronic hepatitis B there was no observed difference in incidence of these events between placebo and ZEFFIX treated patients.
Cases of lactic acidosis, usually associated with severe hepatomegaly and hepatic steatosis, have been reported with the use of combination nucleoside analogue therapy in patients with HIV. There have been occasional reports of these adverse events in hepatitis B patients with decompensated liver disease, however there is no evidence that these events were related to treatment with ZEFFIX.