Peginterferon beta-1a Disease Interactions

Severe hepatic injury, including hepatitis, autoimmune hepatitis, cases of hepatic failure and asymptomatic transient increases in the concentrations of serum transaminases, have been reported in patients treated with beta interferons. In some cases, these events have occurred in the presence of other drugs that have been associated with hepatic injury. The potential risk of these agents used in combination with known hepatotoxic drugs or other products (e.g., alcohol) should be considered before starting therapy, or before starting hepatotoxic drugs. Patients should be monitored for signs of hepatic injury, including the regular monitoring of liver function tests, and discontinuation of therapy should be considered if serum transaminase levels significantly increase or if hepatic injury occurs.

Autoimmune disorders of multiple target organs including idiopathic thrombocytopenia, hyper- and hypothyroidism, and autoimmune hepatitis have been reported with interferon beta. If patients develop a new autoimmune disorder, consider stopping therapy with this agent. Care and close monitoring is recommended when prescribing this agent to patients at risk of developing an autoimmune disorder.

Congestive heart failure, cardiomyopathy, and cardiomyopathy with congestive heart failure occur in patients receiving interferon beta. It is recommended to monitor patients with significant cardiac disease for worsening of their cardiac condition during initiation and continuation of treatment.

Interferon beta can cause decreased peripheral blood counts in all cell lines, including rare instances of pancytopenia and severe thrombocytopenia. It is recommended to monitor patients for infections, bleeding, and symptoms of anemia. Monitor complete blood cell counts, differential white blood cell counts, and platelet counts during treatment. Close monitoring is recommended when prescribing this agent to patients at risk, in particular to patients with myelosuppression.

Depression, suicidal ideation, and suicide have been reported in patients receiving peginterferon beta. Patients should be monitored for any evidence of depression or other psychiatric symptoms. Patients should be advised to report any signs or symptoms of depression, or other changes in mood or behavior. In severe cases, therapy should be stopped immediately and psychiatric intervention should be instituted.

Injection site reactions, including injection site necrosis, can occur with the use of subcutaneous interferon beta. Caution should be exercised when prescribing this agent and the decisions to discontinue therapy following necrosis at a single injection site should be based on the extent of the necrosis. For patients who continue therapy after injection site necrosis has occurred, it is recommended to avoid administration of this agent near the affected area until it is fully healed and if multiple lesions occur, discontinue therapy until healing occurs.

Pharmacokinetic studies have shown that renal impairment can increase the Cmax of Peginterferon beta-1a. Caution should be taken when prescribing this agent to these patients. It is recommended to monitor renal function, and to monitor for adverse reactions due to increased drug exposure in patients with severe renal impairment. Clinical monitoring of renal function is recommended.

The use of peginterferon beta-1a may cause seizures. Exercise caution when prescribing this agent to patients with a history of seizure disorders. Close monitoring is recommended.

Cases of thrombotic microangiopathy (TMA), including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, some fatal, have been reported with interferon beta products. Discontinue therapy if clinical symptoms and laboratory findings are consistent with TMA, and manage as clinically indicated. Care should be taken when prescribing this agent to patients at risk of endothelial injury.