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What is a black box warning?

It is no surprise that not all drugs are equal. While some drugs have minimal side effects, others have more serious ones, along with risks for adverse events. If there are safety concerns about the use of a drug, the U.S. Food and Drug Administration (FDA) applies warnings. The type of warnings found on prescription drug labeling vary depending on the type of side effects. An FDA black box warning draws attention to the drugs with more serious side effects, such as heart failure. The warning alerts prescribers and patients that the drug could have serious or life-threatening risks.

What is a black box warning?

A black box warning, or “boxed warning,” is an FDA warning to alert consumers about serious or life-threatening side effects the drug may have. Found on the package insert for prescription drugs, this is the most serious warning given by the FDA. 

A drug gets a black box warning when it has potentially serious adverse reactions that could lead to hospitalization and death. A black box warning also explains how the reactions may be worse in certain groups of people, such as for women who are pregnant or for children or the elderly. 

All drugs in the United States must go through testing for FDA approval. During this testing, a drug may have side effects that call for a black box warning before going to market. On occasion, during these clinical trials for new drugs, every side effect may not be uncovered since testing occurs in only a few thousand patients. There could be more serious side effects found later, after the drug is already approved, when it’s used in tens or hundreds of thousands of patients. When this happens, black box warnings may be added to the medicine after it has hit the market. 

Where can I find black box warnings?

While black box warnings will appear on the bottle or package insert for a medication, the warning will also appear on the patient information sheet that your pharmacy provides when a prescription is filled. 

Which drugs have a black box warning?

“Over 600 medications have black box warnings and 40% of people are taking at least one medication with a black box warning,” says Rick Rayl, R.Ph, the director of pharmacy at the University Behavioral Health of Denton in Texas. Here are some of the most commonly prescribed drugs with black box warnings listed on the medication guide.

Drug class Drug name Reason for warning
Antidepressants/Selective Serotonin Reuptake inhibitors (SSRIs) Zoloft (sertraline hydrochloride)

Celexa (citalopram hydrobromide)

Prozac (fluoxetine hydrochloride)

All antidepressants received a black box warning in 2004 to warn consumers about an increase in suicidal thoughts and behaviors associated with these drugs for people with mental health problems.
Bronchodilators/LABAs and steroidal anti-inflammatory agents Advair Diskus (fluticasone salmeterol) Increased risk of asthma-associated deaths
Miscellaneous antipsychotic agents Seroquel (quetiapine fumarate) Increased mortality in the elderly that have

dementia-related psychosis and increase of suicidality in children through young adults

Certain analgesics/narcotics OxyContin (oxycodone) Dependence on the drug/addiction
Antibiotics (fluoroquinolones) Levaquin (levofloxacin) Risk of tendinitis and tendon rupture across all ages
Antimetabolites or folic acid antagonists Methotrexate  Increased risk of end-stage liver disease

The anti-anxiety medication Xanax does not currently have a black box warning. However, this is somewhat controversial and there are petitions for all benzodiazepines to have black box warnings added regarding serious adverse withdrawal events from stopping the medication.

What to do if your medication has a black box warning

When starting any new prescription, it is important to go over the drug safety information with your doctor or pharmacist. The decision to take a prescription that has an FDA black box warning should not be taken lightly and should be discussed with your healthcare provider. A conversation with healthcare professionals is the best way to determine if the benefit of the drug outweighs the potential risk in these scenarios. 

“As with all medications, there is a benefit and a cost to consider,” Rayl says. “Consult your pharmacist with questions that will help you decide if this is the right medicine for you.”