How Safe Is It to Consume Alcohol While on Antibiotics

In the National Survey on Drug Use and Health 2018, 86.3% of people aged 18 and older reported they consumed alcohol at one point in their life, 70% reported they drank in the last year, and 55.3% reported drinking in the past month. (1)

Even with these facts, it is rare that physicians discuss the interactions that alcohol can have on other medications being consumed at the same time.

An adverse drug reaction refers to the unintended responses between two or more drugs when used in doses indicated to prevent, treat, and diagnose conditions. It is a very dangerous condition. A key factor responsible for adverse drug reactions is polypharmacy, or the consumption of multiple medications.

Here are some facts related to adverse drug reactions and polypharmacy:

• About two-thirds of patients visiting their doctor will be prescribed medication, and it is estimated that the average American fills out 10 prescriptions annually. (2)
• The chances of an adverse drug reaction go up with four or more medications prescribed.
• Many prescription drugs and OTC preparations can have interactions with alcohol, causing changes in the metabolism of one or the other, leading to dangerous outcomes.

Can You Take Antibiotics With Alcohol?

Most antibiotics have package inserts that mention avoiding alcohol, and a few can cause a “disulfiram-like reaction.”

Disulfiram is a drug that was used to deter alcoholics from drinking. It worked by inhibiting acetaldehyde dehydrogenase, causing acetaldehyde to accumulate. This effect leads to facial flushing, chest tightness, nausea, and vomiting.

Thus, when a person is on disulfiram, ingesting alcohol would most definitely cause an unpleasant reaction and, consequently, an aversion to alcohol.

Although disulfiram is no longer being used to treat alcoholics, a similar reaction is experienced with certain antibiotics (listed below). Patients taking these antibiotics have to be warned to abstain from alcohol consumption as it could lead to serious medical consequences.

Aside from producing a disulfiram-like reaction, antibiotics such as erythromycin can increase the forward movement of the intestines, causing a rapid increase of alcohol level in the blood. Isoniazid can cause liver damage on top of the effect of long-term alcohol consumption. (3)

Antibiotics (brand names included) that cause an adverse reaction with alcohol:

Metabolism of Alcohol

Most of the alcohol that is absorbed through the stomach and small intestines makes its way to the liver, which helps break it down and eliminate it from the body.

In the liver, two enzyme systems work on the breakdown of alcohol – ADH and the CYP2E1. No two people have the same quantities of these enzymes. Alcohol dehydrogenase (ADH) breaks down alcohol into acetaldehyde, and then another enzyme turns it into a nontoxic form.

The larger enzyme system responsible for alcohol-medication interactions is cytochrome p450, which consists of cytochrome reductase and CYP2E1. This enzyme system can be induced or inhibited by various foods or medications, which increase and decrease its metabolizing capability, respectively.

In a person who consumes alcohol occasionally, the cytochrome enzyme system breaks down only a small percentage of alcohol. In a chronic alcoholic, the same enzyme is in greater quantities and thus can metabolize larger fractions of alcohol.

Well-documented studies have shown interactions that have occurred in chronic alcoholics in whom the CYP2E1 enzyme system has been triggered to increase its metabolizing capability. Certain medications in such individuals have to compete with alcohol for CYP2E1, which can lead to fatal overdoses or reduced efficacy of medication. (4)

Moderate vs. Heavy Drinkers

Most studies on the harmful interaction between alcohol and medications have been in chronic alcoholics, and there is a lack of data on the same with moderate alcohol consumption.

Thus, taking antibiotics along with moderate consumption of alcohol is not considered dangerous, although one must thoroughly read the warnings and contraindication on the package inserts of antibiotics.

Moderate alcohol consumption is defined by the US Department of Health and Human Services as one standard drink per day for women and two standard drinks per day for men. (5)

Heavy drinkers usually consume 5 or more per day or 15 or more in a week for men and 4 or more per day or 8 or more per week for women. Alcohol consumption can have an effect on the disease state for which the medication is prescribed. For instance, alcohol can worsen blood pressure in people with high blood pressure.

Furthermore, older people may suffer more harm due to the natural physiological changes that cause a lesser breakdown of alcohol, and because this age group tends to have multiple prescribed medications.

Heavy drinking can also lower the body’s immunity, leading to increased chances of infections and a delayed response in healing.

Final Word

Alcohol has complex interactions with medications, leading to either reduced efficacy or adverse effects, some of which can be fatal.

Evidence-based literature has demonstrated the increased risk of such adverse reactions in chronic alcoholics, but there is little evidence to back the same in people consuming moderate amounts.

Some antibiotics react with alcohol to cause a disulfiram-like reaction, which includes flushing of the face, nausea, vomiting, and chest tightness, which can be fatal.

Antibiotics such as isoniazid and chloramphenicol can add to the liver damage caused by alcohol consumption. Prescribing physicians must caution patients about the use of such antibiotics in the presence of alcohol.