As the holiday season gets underway, Americans are beginning to note recipes for festive cocktails and choose the best wines for the dinner table.

But experts are raising the alarm about potentially deadly interactions between alcohol and certain medications.

Alcohol is a depressant, meaning it slows down the functioning of the central nervous system, impacting brain activity, reaction time, speech and a person's mental well-being.

Adding certain medications on top of consuming alcohol - such as anti-anxiety drugs, drugs for insomnia, blood thinners and antidepressants - compounds these effects. 

The deadly combination can destabilize the heart's rhythm and blood pressure. And, because both the medications and the alcohol independently suppresses brainstem activity, which controls automatic functions, the combination reduces the brain's drive to breathe.

But more innocuous medications do not play well with alcohol, either. That group includes over-the-counter pain relievers like ibuprofen, which can contribute to liver and gastrointestinal damage.

Combining ibuprofen and alcohol raises the risk of bleeding in the stomach and small intestine, which can result in vomiting blood. 

Dr Barbara Sparacino, an adult and geriatric psychiatrist, told the Daily Mail that a practical rule of thumb is to avoid mixing alcohol with any medication that helps you sleep, relax or relieve pain. 

For stronger sedatives, such as opioids and benzodiazepines, complete abstinence from alcohol is safest. 

And if you do decide to drink, you should avoid drinking heavily and never drive after. 

By one estimate, roughly 40 percent of Americans take a medication that interacts dangerously with alcohol.

In addition to dangerous side effects, the medicine might lose its efficacy when it comes in contact with alcohol and speed its clearance from the body without working as intended.

A medication can also influence the absorption of alcohol, potentially resulting in higher blood alcohol concentrations (BACs) and other adverse effects like shallow breathing and overdose.

Alcohol can also heighten the effects of a medication and increase the amount of it in a person's body.

After speaking with several doctors, the Daily Mail can reveal which over-the-counter and prescription medications you should not mix with alcohol - along with the experts' reasons why.

Over-the-counter pain relievers

Non-steroidal anti-inflammatory drugs such as ibuprofen (sold under the brand names Advil and Motrin), naproxen (sold as Aleve and Naprosyn) and aspirin are associated with a higher risk of GI bleeds on their own. But, when combined with just one drink, that risk climbs by about 37 percent.

It's likely fine to take an occasional dose of ibuprofen if you've consumed a small quantity of alcohol, roughly one or two drinks. The combination becomes more dangerous if you take ibuprofen regularly and tend to drink heavily. 

Acetaminophen (sold as Tylenol) is the most popular pain reliever in the US, but it interacts in a unique - and potentially deadly - way with alcohol.

Taking too much acetaminophen accounts for almost half of all cases of acute liver failure in North America and approximately 20 percent of liver transplant cases in the US. Mixing acetaminophen with alcohol compounds the risk of deadly liver damage.

The liver of a person who drinks heavily and often produces more of a specific enzyme called CYP2E1 to break down the alcohol. This same enzyme also processes acetaminophen. The problem is that this process creates a toxic byproduct called NAPQI.

Taking acetaminophen preemptively or after heavy drinking causes the overactive enzyme system to produce dangerously high levels of NAPQI, which can overwhelm and destroy the liver.

Because of this, the FDA has mandated that every bottle of acetaminophen products have a label stating that 'severe liver damage may occur if an adult has three or more alcoholic drinks every day while using this product.'

Over-the-counter cold and flu medicines

Cold and flu remedies should never mix with alcohol. 

A bad flu is dehydrating, and adding alcohol dehydrates the body further as alcohol triggers a diuretic effect. All of the efforts to hydrate, from bottles of water to a bowl of soup, are then eliminated. 

Dehydration can exacerbate flu symptoms like headache, fatigue, dizziness and muscle weakness, and ultimately prolong recovery. 

Alcohol also exacerbates the side effects of popular cough medicines like Theraflu cough syrups, Dayquil, Nyquil and Tylenol Severe Cold and Flu. 

Like alcohol, their main ingredient, dextromethorphan (DXM), is a central nervous system depressant. 

Combining the two increases side effects such as dizziness, drowsiness, impaired coordination and difficulty concentrating. People who combine the two are at higher risk of light stumbles turning to dangerous falls and other injuries. 

Taking DXM with alcohol can also cause breathing to slow or stop entirely, feelings of dissociation, brain lesions, epilepsy or permanent psychosis. It is best to avoid alcohol until the drug has left your body, about 24 to 48 hours after your last dose. 

Allergy medicines

Alcohol heightens the side effects of popular allergy medicines, including Mucinex, Allegra, Claritin and Zyrtec, leaving you feeling more drowsy, dizzy or impaired than you would from the medication alone.

Many antihistamines - the main ingredients in allergy medicines - are central nervous system depressants just like alcohol. Combining them can have an additive effect, slowing down brain activity more than either substance would by itself.

Benadryl, the oldest generation of current allergy medications, has a stronger sedative effect than others, and that effect is amplified further when combined with a drink.

Sudafed, a common nasal decongestant, is a stimulant that can mask the sedating effects of alcohol and make someone feel less intoxicated than they actually are. This can cause a person to drink more than they intended, raising the risk of alcohol poisoning. 

Both Sudafed and alcohol can raise heart rate and blood pressure individually. Combining them can heighten this effect, which is especially dangerous for individuals with preexisting heart conditions or hypertension. 

For safety, it is generally recommended to avoid alcohol when taking these medications, especially if you need to drive or operate machinery. 

Antibiotics

Combining alcohol with antibiotics can interfere with your body's healing process in several key ways. 

First, alcohol can impair the immune system's efficiency, making it harder for the body to fight the very infection the antibiotic is meant to treat. This can potentially prolong illness and delay recovery. 

More directly, both alcohol and many antibiotics are metabolized by the liver. Consuming them together places a significant strain on this vital organ, as it must work overtime to process both substances. 

This can exacerbate common antibiotic side effects like nausea, dizziness and drowsiness, making a person feel significantly worse. 

In the case of certain antibiotics, like metronidazole, the interaction is severe and deliberate, causing a chemical reaction that leads to intensely unpleasant symptoms such as severe vomiting, rapid heart rate and headache. 

Beyond the immediate discomfort, mixing alcohol and antibiotics can compromise the medication's effectiveness. Alcohol can disrupt the absorption and metabolism of the drug, potentially lowering its concentration in the bloodstream to a level that is insufficient to eradicate bacteria. 

This not only risks treatment failure, but contributes to a larger public health crisis: antibiotic resistance. When antibiotics are not allowed to work at full strength, it creates an environment where stronger, more resistant bacteria can survive and multiply.

Therefore, abstaining from all alcohol for the full duration of the prescription is critical. 

Antidepressants

Combining antidepressant medications with alcohol has a similar effect on the respiratory system as benzodiazepines. 

While drinking may provide temporary relief from depression symptoms and aid in dealing with social anxiety, alcohol blocks the ability of antidepressants to do their job. 

SSRIs like Zoloft and Prozac, and SNRIs like Effexor work over time to regulate and stabilize key neurotransmitter systems (serotonin and norepinephrine) to improve mood, sleep and anxiety in a sustained way.

Alcohol is a chemical disruptor. It initially causes a brief, artificial release of serotonin and dopamine, creating a mood boost, but a rapid depletion of those neurotransmitters follows. 

In the short term, this leads to mood swings. With regular use, it can create or worsen a chemical imbalance that promotes depression and anxiety.

The combination impairs reaction time, judgement, and decision-making more than either substance on its own, and, due to the depletion of mood-boosting neurotransmitters, has a higher likelihood of causing suicidal ideations. 

Drinking while taking antidepressants also reduces the odds that the medicine will work as intended. 

There's no universally safe limit for drinking alcohol while taking antidepressants, because even a small amount can interact poorly with the medications and make depression or anxiety worse. 

Many doctors advise avoiding alcohol altogether or sticking to one to two moderate drinks - a 12-ounce beer, a five-ounce glass of wine or a one-ounce shot of liquor, regardless of gender.

Benzodiazepines 

Alcohol is implicated in approximately 20 percent of all benzodiazepine overdoses, constituting one of the most dangerous drug interactions.

People taking benzodiazepines should avoid alcohol entirely.  

The danger primarily stems from how both substances profoundly suppress the central nervous system, specifically targeting the body's capacity to breathe. When combined, they dramatically increase the risk of severe and potentially fatal respiratory depression.

This life-threatening consequence occurs because both alcohol and benzodiazepines, along with many antidepressants, amplify the effects of the neurotransmitter GABA (gamma-aminobutyric acid).

GABA is responsible for calming neural activity, and its excessive enhancement leads to extreme sedation of the body's vital functions, resulting not only in respiratory failure but also in cardiovascular collapse.

Beyond the acute physical dangers, the mixture of benzodiazepines and alcohol can induce severe psychological and behavioral problems.

Users may experience complete anterograde amnesia, in which they cannot form new memories properly, losing all memory for hours while conscious and active.

This blackout state is associated with high-risk behaviors, including unsafe sexual practices, impulsive aggression or severe self harm. 

Individuals may experience intense suicidal thoughts and act on them, with no subsequent recollection of their actions, creating a uniquely hazardous situation for both the individual and those around them.

'This combination is a major contributor to ER visits and accidental overdoses, even at doses people think are "normal,"' Sparacino said.

The risk of severe interactions are even higher among older people.  

'So a drink that felt "mild" at 40 can feel like three drinks at 75, especially when layered on top of sedating meds,' she added.

'That's part of why we see more falls, confusion and ER visits in older adults mixing alcohol with prescriptions.' 

Blood thinners

Just as risky are prescription blood thinners, common among older people with blood clotting disorders that increase the risks of heart attack and stroke. The danger comes as alcohol can significantly raise someone's risk for dangerous bleeding.

Both alcohol and blood thinners independently inhibit the blood's ability to clot. Together, their effects can be more than additive, creating a powerful synergy that makes bleeding much harder to stop.

For example, a simple scrape or nick that would normally stop bleeding within minutes could bleed for much longer. 

Alcohol also irritates the stomach lining, and any kind of perforation due to an ulcer can cause internal bleeding in the GI tract.

Other popular blood thinners significantly alter alcohol metabolism. This means that a person who drinks a modest amount but is on a blood thinner might actually have a much higher BAC than a person who drinks the same amount of alcohol but is not taking the medication. 

Alcohol can also cause dangerously low blood pressure, causing dizziness and fainting.

To prevent the negative effects, doctors recommend that patients limit their alcohol intake to one to two standard drinks at a time, alternating with water.

Sometimes taken in addition to blood thinners are cholesterol medications known as statins. These come with their own risks when paired with alcohol, Dr Raul Santos, a board-certified cardiovascular specialist, told the Daily Mail. 

'Excessive alcohol consumption or binge drinking in individuals using statins may increase the risk of muscle problems, muscle aches and, very rarely, muscle inflammation or even destruction of muscle cells [Rhabdomyolysis],' Santos said.

Muscle aches in randomized controlled trials occur in one to three percent of the population, while in real life, numerous confounding factors affect ten to 20 percent of people.

'Rhabdomyolysis is extremely rare, occurring in 0.01 percent of patients taking statins. Excess alcohol can harm the muscles, and statins may exacerbate this effect.'