Because NyQuil is an over-the-counter medication, many people assume it must be safe — and it generally is when it’s used as directed. But combining NyQuil with alcohol can be dangerous and even deadly.
You should never drink alcohol while using NyQuil. The flu and cold medicine medication and its store-brand versions contain several ingredients that can interact with alcohol and cause drowsiness, dizziness and even liver damage.
NyQuil contains the active ingredient in Tylenol, acetaminophen, and mixing alcohol with acetaminophen is hard on the liver.
Acetaminophen is a popular pain reliever and fever reducer that is present in more than 600 medications — and acetaminophen overdose is the leading cause of acute liver failure in the United States.
Every year, acetaminophen overdoses send more than 78,000 people to the emergency room, and approximately 10 percent of acetaminophen-related liver injuries are linked to over-the-counter combination cold and flu medications, such as NyQuil.
An estimated 150 people die annually from accidental acetaminophen overdoses, and combining alcohol with acetaminophen increases the risk of liver injury.
Every standard two-tablespoon dose of NyQuil contains 650 milligrams of acetaminophen, and NyQuil manufacturer Procter & Gamble warns on its website that severe liver damage may occur if you drink three or more alcoholic beverages while taking NyQuil.
The danger stems from the way the body breaks down acetaminophen. When acetaminophen is metabolized, it’s broken down into several byproducts, including a toxic substance called NAPQI that’s exceptionally toxic to the liver.
Normally, the liver produces a powerful antioxidant called glutathione that neutralizes NAPQI and prevents it from hurting liver cells. But heavy drinking causes a drop in glutathione, allowing NAPQI to wreak havoc on the liver.
Drinking alcohol can also increase the side effects of dextromethorphan, or DXM, the cough suppressant component of NyQuil.
More than three percent of 10th- and 12th-graders have reported abusing cough medicines to get high.
Dextromethorphan works by suppressing the cough reflex in the brain. It’s the same active ingredient found in more than 120 other over-the-counter cold medications, including the cough suppressants Robitussin and Coricidin.
When it’s taken as directed, DXM is usually safe and rarely causes side effects. But combining DXM with alcohol is extremely dangerous and can even kill you. Side effects can range from dizziness and lightheadedness to drowsiness, nausea and vomiting.
Unfortunately, recreational abuse of products containing DXM by teens and adolescents has become an increasingly common problem. More than three percent of 10th- and 12th-graders have reported abusing cough medicines to get high, and DXM abuse results in approximately 6,000 emergency department visits every year, according to the National Capital Poison Center.
Taking excessive amounts of DXM — a practice known as “robotripping” or “skittling” — can cause euphoria, hallucinations, distorted visual perception, loss of motor coordination and sedation.
Some DXM abusers purposely swig alcohol with cough syrup to enhance these psychoactive effects and end up overdosing. Using alcohol in combination with DXM can cause shallow breathing, stupor, coma and death.
Some people are at a higher risk of DXM overdose than others. Between five and 10 percent of white individuals don’t metabolize DXM very well and are at an increased risk for overdose and death from DXM, according to the Drug Enforcement Administration.
NyQuil relieves cold and flu symptoms such as a runny nose and sneezing with doxylamine succinate, an antihistamine medication.
Like many antihistamines, doxylamine causes extreme sleepiness, dizziness and light-headedness, and alcohol can increase these effects. Combining the two can also cause slowed breathing, impaired motor control, unusual behavior and memory problems.
The sedating effects of doxylamine are so pronounced that it’s the main ingredient in some over-the-counter sleep aids, including Unisom and ZzzQuil.
That’s why doxylamine is an ingredient of NyQuil, which is intended for nighttime use only, but not DayQuil. Mixing alcohol and DayQuil is also dangerous, and it carries many of the same risks that one encounters when using NyQuil.
Interestingly, the liquid version of NyQuil contains 10 percent alcohol; NyQuil LiquiCaps do not. An alcohol-free version of liquid NyQuil Cold & Flu Nighttime Relief Liquid is available, according to the manufacturer.
Aside from the dangers mentioned above, chances are if you are taking NyQuil, you’re fighting some kind of virus or infection.
Unfortunately, alcohol impairs the immune system in several ways, making it harder for your body to recover from what’s ailing you.
Alcohol reduces the number of white blood cells that normally patrol the bloodstream, looking for invaders and gobbling them up. Alcohol also impairs the body’s production of cytokines, which coordinate the body’s overall immune response.
While Procter & Gamble suggests not exceeding three alcohol drinks per day while taking NyQuil, a better bet is to avoid alcohol altogether. This will help keep your immune system in tip-top form and avoid any harmful interactions with NyQuil’s key ingredients.