It is possible that interferons can reduce the activity of liver enzymes that break down other active ingredients. This can cause a delay, for example, in the breakdown of antidepressants or antiepileptic drugs, which are almost completely metabolized in the liver. If necessary, the dosage of these drugs must be adjusted. Caution should also be exercised when using additional active substances affecting the liver and the hematopoietic system, as this can lead to an increased risk of side effects. Interferon treatment can increase the risk of organ rejection in transplant patients taking immunosuppressants. Interferons can also enhance the effects and side effects of theophylline (a drug used for asthma) by causing, for example, headaches, nausea, vomiting and a rapid heartbeat. Other known interferences are listed below; however, this is not a complete list. Interferon beta
No interaction studies have been carried out for interferon-beta. Due to a lack of clinical experience, concomitant administration of other immunomodulators other than glucocorticoids and ACTH is not recommended during interferon beta treatment. Interferon may react with the antiretroviral (HIV/AIDS treatment), zidovudine. Interferon alpha
Interferon -alpha and peginterferon -alpha should not be taken together with telbivudine (used for hepatitis B), as it can cause damage to the peripheral nerves.
Interferon gamma
Interactions with interferon gamma have been ascribed to liver, kidney, neuro- and cardiotoxic agents, myelosuppressive agents, serum proteins, immunological preparations such as vaccines and CYP substrates.