Neuraminidase inhibitors are used to treat influenza A and B, and to prevent the flu in people who have been exposed to the virus. They work by blocking the neuraminidase enzyme (protein), which helps stop the flu virus from spreading in your body. Neuraminidase inhibitors come in different forms, including oral capsules, inhaled powders, and injectable solutions. Examples include oseltamivir (Tamiflu), which is taken orally, and zanamivir (Relenza), which is inhaled. Another option is peramivir (Rapivab), which is given as an injection. You can discuss with your healthcare team which option might be right for you.