When friends and family get together, there are often people who turn red after drinking. The main culprit for a red face after drinking is not alcohol (ethanol), but acetaldehyde. In the body, alcohol is first catalyzed into acetaldehyde, and then further broken down by the enzyme aldehyde dehydrogenase 2.
If this enzyme's activity is impaired, acetaldehyde cannot be metabolized in time and accumulates in the body. This can cause the facial blood vessels to dilate, leading to a red face. In severe cases, it may cause damage to organs such as the heart, brain, liver, and kidneys. People who flush easily when drinking should be cautious when taking medication, especially with the following three types of drugs.
Nitroglycerin: The emergency medication may be ineffective
As is well known, if angina pectoris is not treated promptly, it can lead to acute myocardial infarction, and even sudden death due to severe arrhythmia. Nitroglycerin is a "lifesaving drug" for treating angina pectoris. However, in the Han Chinese population, the proportion of it being ineffective is as high as 25%, many of whom are people who flush easily when drinking. Aldehyde dehydrogenase 2 specifically metabolizes nitroglycerin to produce nitric oxide, which dilates blood vessels and relieves angina. The activity of aldehyde dehydrogenase 2 in people who flush after drinking is often low, so the effect of taking nitroglycerin may be poor or even ineffective. It is recommended that these patients use nitroglycerin cautiously under a doctor's guidance, and have an alternative or switch to other medications when necessary, such as nitrate esters, beta-blockers, calcium channel blockers, or traditional Chinese medicine preparations like Suxiao Jiuxin Wan and She Xiang Bao Xin Wan, to prevent improper medication from delaying treatment and causing life-threatening risks.
Multiple types of antibiotics: May cause severe symptoms such as intense headaches and rapid heartbeat
In addition to being careful with nitroglycerin, one should also be cautious with antibiotics for a period after drinking. Multiple antibiotics can bind to aldehyde dehydrogenase 2, inhibiting its activity, which prevents acetaldehyde from being metabolized in time and causes it to build up in the body, leading to a disulfiram-like reaction. Its clinical manifestations include facial heat, bright red complexion, intense pulsation of blood vessels in the head and neck or pulsating headaches. In severe cases, symptoms such as difficulty breathing, nausea, vomiting, sweating, dry mouth, chest pain, rapid heartbeat, decreased blood pressure, agitation, and even shock may occur. Drugs that can cause a disulfiram-like reaction include: metronidazole, ketoconazole, chloramphenicol, and certain cephalosporin antibiotics. People who flush easily when drinking are particularly sensitive to this reaction. It is generally not advisable for most people to take antibiotics within 3 days of drinking, but for those who flush easily, this period is recommended to be 5 to 7 days, or even longer.
Diuretics: Can cause low blood pressure
Both ethanol and its metabolite, acetaldehyde, have vasodilatory effects and can enhance the efficacy of vasodilators. Especially when using thiazide and other diuretic antihypertensive drugs, drinking can aggravate orthostatic hypotension. People who flush easily when drinking have a poor ability to metabolize acetaldehyde, making them more prone to danger. Therefore, alcohol consumption should be avoided when taking such medications.
Flushing after drinking is also related to factors such as environment, diet, and an individual's health status. Medication must always be taken under the guidance of a doctor or pharmacist. Some drug labels explicitly state that alcohol must be avoided during the course of treatment. When taking these medications, regardless of whether you flush easily, you should not drink alcohol.