You’ve got all the telltale signs: body aches, fever, chills, a dry cough. It’s the flu. For most people, this means a few days in bed, feeling lousy. But for others, getting the flu means the risk of serious illness, such as pneumonia. If you’re one of these people, you should think about taking a prescription medicine at the first signs of the flu. Here’s some important information to help you decide. How Flu Medicines Work Medicines to treat the flu are called antiviral drugs. They can ease flu symptoms and shorten the time you’re sick. They can also help prevent you from getting more serious problems from the flu. You can only get these medicines with a prescription from your doctor. They come in liquid, pills, or a powder that you inhale. There are two antiviral drugs that have been approved by the FDA to treat the flu: oseltamivir (Tamiflu ) and zanamivir (Relenza ). When to Take Flu Medicine The best time to take these medicines is 1 to 2 days after your flu symptoms start. But taking them later can still help. Most people take the medicine for 5 days, although some people may need to take it longer. Who Should Use These Medicines Only people who have a high risk of serious problems from the flu should take these medicines. These include people who are: Older than age 65 Younger than age 5, but especially those younger than 2 Younger than age 19 and on long-term aspirin therapy Pregnant or have given birth in the past 2 weeks Alaska Native or American Indian Morbidly obese (BMI of 40 or higher) You also have a higher risk of problems from the flu if you have certain health conditions including: Blood disease such as sickle cell disease Chronic lung disease, such as asthma, COPD, or cystic fibrosis Diabetes Endocrine or metabolic disorder Heart disease Immune disorder, such as HIV or/ AIDS, or a weakened immune system Kidney or liver condition Neurological or neurodevelopmental condition If you have any of these conditions and begin having flu symptoms, ask your doctor about antiviral medicines right away. You Still Need a Flu Shot Antiviral medicines for flu don’t replace the flu vaccine. Getting a flu shot or the flu mist every year is still the best way to protect yourself from the flu. Key Takeaways For people who risk having complications from the flu, taking an antiviral medicine at the first signs of flu can help protect you against more serious illness. Prescription flu medicine is most effective around 1 to 2 days after you start having symptoms. But contact your doctor or go to a clinic even it’s been more than 2 days because the medicine can still help.