An opioid overdose is an emergency when a person is experiencing severe respiratory problems or severe liver failure, according to the U.S. Food and Drug Administration (FDA).

The drug, which can be bought legally in many states and is usually prescribed for acute pain or pain in a chronic medical condition, is also known as oxycodone or hydrocodone.

The FDA issued guidance on Monday about how to recognize an overdose, which was based on data from the Centers for Disease Control and Prevention (CDC).

The CDC estimates there are about 4.7 million prescriptions for opioids, but the agency says there are also about 10 million patients who have not received any opioid-based medication since they received it in the first year of their life.

The CDC recommends that anyone who is at risk of becoming addicted to opioids or a chronic condition should seek treatment and seek a prescription from a doctor, the agency said.

However, it said that a person with a medical condition such as asthma, liver disease, diabetes or depression may be at risk for overdose.

The guidelines also called for people to seek immediate medical care if they have signs of an opioid overdose, including:Dizziness, tingling or pain during a physical exam, vomiting, abdominal cramps, difficulty breathing, difficulty swallowing, or other symptoms, including headache, difficulty talking, difficulty thinking or feeling, or difficulty sleeping.

Other signs of opioid toxicity include loss of consciousness, weakness, coma, loss of feeling, difficulty walking, rapid heart rate, muscle spasms, rapid breathing, or sudden changes in heart rate or blood pressure.

Emergency rooms should not treat opioid overdose patients unless they are not responding well to other treatments and are unable to communicate.

The CDC advises that all opioids should be administered in the same dose, including when the person is not responding.

Emergency medical personnel are trained to administer first aid to anyone who may be exposed to an overdose.

They should also follow the instructions of the provider if administering pain medication.

The guidance recommends that emergency medical providers prescribe oxygen, intravenous fluids, and other treatments for anyone who has not received opioids or is unable to speak.