It is known, many drugs have side effect. Sometimes it will be more dangerous when taking over two kinds of drug at same time. Recently Health Canada is warning consumers being treated with Sebivo for hepatitis B not to combine the medication with any interferon products because of potentially serious drug interactions.
Taking both Sebivo (telbivudine) and interferon may increase the risk of peripheral neuropathy, a condition marked by weakness, numbness, tingling and burning sensations in the arms and-or legs.
The anti-viral agent is authorized by Health Canada for use alone, not in combination with any interferon products, including standard or pegylated types of interferon alfa (marketed under brand names such as Pegasys, Pegatron, Intron A, Unitron Peg, Rebetron, Roferon A, and Infergen) and of interferon beta, (marketed under brand names such as Rebif, Betaseron and Avonex).
The drug's maker, Novartis Pharmaceuticals Canada Inc., said that in a small clinical trial testing the use of both Sebivo and the interferon product Pegasys (peginterferon alfa-2a), serious peripheral neuropathy occurred in five out of 48 patients (10 per cent), and was occasionally disabling. The condition usually started about three months after treatment began.
Health Canada said Wednesday it is not yet known if this adverse event is reversible once treatment is stopped, or whether it might also occur when the drug is used with interferon products other than Pegasys.
Consumers are advised to tell their doctors if they are taking Sebivo and an interferon product, but should not discontinue or modify Sebivo without first consulting their physician, due to the risk of worsening the hepatitis B infection.
Peripheral neuropathy has been reported in five out of 2,000 patients (less than one per cent) using telbivudine alone in clinical trials. The disorder also is a common adverse reaction of Pegasys (reported on average in one to five out of 100 patients in clinical trials).
The risk of developing peripheral neuropathy is increased when a patient receives telbivudine in combination with Pegasys, compared to either treatment alone, Health Canada said.
Consumer information for telbivudine is being updated and Novartis has issued a letter to health professionals advising them of the new safety information.