There is nothing trivial about safe drug use. The interactions between drugs and drugs and between drugs and food are complex. Sometimes the interactions between drugs can lead to a good medicine turning into a poison. Especially for some older patients, take more medicine, to make the situation of their own medicine which food is not to eat, and which drugs can not be taken at the same time. Here’s a list of some common error-prone combinations of drugs and foods to keep in mind.
So let’s talk about liver drug enzymes and drug interaction
Liver drug enzymes
Cytochrome P450 is a major enzyme in drug metabolism. Cytochrome P450 is divided into many types, including CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, etc., among which CYP3A4 is the most important. Some drugs and foods can inhibit and induce the activity of these liver drug enzymes. If the liver drug enzyme is inhibited, the corresponding metabolism of the drug is reduced; Instead, it is induced, and the metabolism of the drug is enhanced.
First pass effect of drugs
When the drug is taken orally, it enters the small intestine, the large intestine, is absorbed into the blood, and then travels through the blood circulation from the portal vein to the liver, and then through the systemic circulation to the rest of the body. A portion of the drug is metabolized in the gastrointestinal tract and liver, a process known as first-pass effect. If the initial effect is too strong, then too much of the drug is consumed in the gastrointestinal tract and liver, and less can be used. This is bioavailability. If the first pass effect is too strong, the bioavailability is low. The adverse effects of drugs are also produced by drug enzymes, and the most important drug enzyme in the small intestine is ALSO CYP3A4.
1,Roxithromycin + compound methoxamine = aminophylline poisoning
A few years ago, an 18-year-old girl in a certain area died of roxithromycin and compound methoxamine
Roxithromycin is a macrolide antibiotic, which is a kind of liver drug enzyme inhibitor, mainly inhibiting the most important liver enzyme CYP3A4. Erythromycin and clarithromycin had the strongest inhibitory effect among macrolide antibiotics, while azithromycin had almost no inhibitory effect Compound methoxamine is a respiratory system drug, containing aminophylline, methoxamine, chlorphenamine, etc., mainly used for asthma, bronchitis, cough, sputum, wheezing symptoms. Aminophylline is metabolized mainly through CYP3A4.
So when aminophylline and roxithromycin are taken together, roxithromycin inhibits CYP3A4. As a result, the first pass effect of aminophylline in the body and the liver metabolism are slowed, so the concentration in the body is increased. However, aminophylline treatment window is relatively narrow, between 5ug/ml-20ug/ mL, effective drug concentration and toxic dose are relatively close, easy to cause poisoning. Therefore, taking roxithromycin and aminophylline at the same time may lead to aminophylline concentration > 20ug/ml, headache, nausea, vomiting, severe arrhythmia, or even shock, which is life-threatening. Roxithromycin as an antibiotic, compound methoxide as a kind of asthma, cough medicine, is likely to be taken at the same time when a cold, if people do not know, at the same time to eat it may have an accident.
Other Chinese patent medicines containing aminophylline: Shun Qi Huatan granules, Zhubei Dingchuan pills, Pingchuan anti-inflammatory capsules, Jiangdan Kechuan tablets.
Four classes of antibiotics that may cause aminophylline poisoning:
Macrolides (erythromycin, clarithromycin, roxithromycin)
Quinolones (Norfloxacin, ofloxacin, ciprofloxacin)
Tetracycline class: minocycline, doxycline
Lincomycin: clindamycin, lincomycin
2,Huoxiang zhengqi water + cephalosporin = disulfiram reaction
From time to time, we can see such news that XX suffered from heatstroke and suffered chest tightness, shortness of breath, dyspnea, headache, blood pressure drop and other symptoms after drinking huoxiang Zhengqi water. The reason was that she also took cephorin that day, which caused disulfiram reaction.
Alcohol is metabolized into acetaldehyde in the body, and acetaldehyde is metabolized into acetic acid before being excreted. The accumulation of acetaldehyde in the body is harmful. The disulhanam reaction, in which the drug inhibits the metabolism of acetaldehyde, causes it to accumulate in the body, causing poisoning and, in severe cases, death.A lot of people know, cannot eat cephalosporin, metronidazole after drinking these medicine. But what some people don’t know is that some drugs contain alcohol. For example, huoxiang Zhengqi Water contains 40-50% alcohol.
What are some common drugs that contain alcohol:
Huoxiang Zhengqi Water (containing 40%-50% ethanol), Ten Drops (containing 60%-70% ethanol), Compound licorice oral solution (containing licorice extract and compound camphor tincture), Cold cough syrup (containing licorice extract and orange peel tincture)Cyclosporine oral solution, l-carnitine oral solution (containing a small amount of ethanol), digoxin oral solution (containing 9% to 11% ethanol), Ergocontine caffeine oral solution (containing 5.8% (V/V) ethanol), ketorolac trotramine tablets/capsules.
Drugs that cause disulfiram reactions:
Cephalosporin antibiotics: cefoperazone, cefmendo, cefmetazole, cefmenoxime, cefnixime, cefoxitin, cefuroxime, ceftazidine, ceftriaxone, cefpiamine, cefminol, and cephalosporin.
Nitroimidazole: metronidazole, tinidazole, ornidazole, etc
Nitrofurans: furantoin, furazolidone
Sulfonylurea hypoglycemic drugs: glibenclamide, gliclazide, glipizide, gliquinone, glimepiride, etc
Biguanide hypoglycemic drugs: benzeneformin, metformin
To prevent disulfiram reaction, refrain from alcohol for two days before taking the drug and drink alcohol for seven days after stopping the drug. Taking medicine with alcohol is not advisable
3,Tome blood pressure drugs + grapefruit = blood pressure drop
High blood pressure of human body is not good, low is also not good, only maintain in a certain range is safe. Therefore, blood pressure medication is also a double-edged sword, to reduce blood pressure to the appropriate range is the best, too much will cause problems. Grapefruit is a delicious fruit, but patients taking certain blood pressure medications (such as nifedipine, felodipine) should not take it, because taking the drug and eating grapefruit can cause blood pressure to drop too much.
Grapefruit contains active ingredients such as furanocoumarin and naringin, which can inhibit the activity of liver drug enzyme (CYP3A4), reduce the first-pass effect of drugs and slow down the speed of liver clearance of drugs. The long-acting antihypertensive drugs are released slowly in the body, and the concentration of the drug is maintained in a certain range throughout the day, so as to reduce blood pressure smoothly. But if grapefruit is eaten, the liver’s clearance of the drug is reduced. On the one hand, antihypertensive drugs are constantly released; On the other side, liver clearance is weakened. As a result, the concentration of the drug in the body increases dramatically, causing blood pressure to drop too low.
What consequence can blood pressure bring about too low possibly?
If blood pressure is too low, the blood needed by various tissues of the human body will not be able to enter, which will lead to ischemia. For example, the heart and brain may suffer from ischemia due to low blood pressure, resulting in cerebral infarction and myocardial infarction. In particular, some hypertensive patients, often combined with coronary heart disease, cerebral arteriosclerosis these cardiovascular diseases, more need to pay attention to.
Since grapefruit is the cause of the liver’s reduced ability to clear drugs, the theory is that any drugs that are cleared in the liver will be affected. Statins, for example, are metabolized in the liver except for rosuvastatin and pivastatin to a lesser extent. And the adverse effects of statin are related to the concentration of the drug, so in long-term statin patients, if they eat grapefruit, they may have an increased risk of adverse effects. Take some sedative sleeping pills (diazepam, midazolam) to eat grapefruit, may strengthen the effect, strengthen the side effects of vertigo, sleepiness.
4,Excessive acetaminophen = impaired liver function or even liver failure
Acetaminophen is a classic antipyretic that is safe to take at regular doses. But overdoses can cause liver damage and, in severe cases, death from liver failure. Acetaminophen should be given 0.3 to 0.6 grams each time, 3-4 times a day, but the daily dose should not exceed 2 grams. Take more than 4 hours between doses. It’s not uncommon to see cases of acetaminophen overdose causing liver damage. The reason may be that they don’t know or don’t care when they know:
Acetaminophen is so common in everyday life, but it’s so hidden that some people don’t know it’s there. Some of our common cold medicines contain acetaminophen. For example, cold spirit, cold qing, Tylenol, vitamin C yinqiao tablets and so on. Some people may think that taking one more medicine will make a cold go away faster. Therefore, two kinds of cold medicine are used together. This is more dangerous. For example, ganggangling particles contain 0.2 grams of acetaminophen per bag and 0.325 grams of Tylenol per pill. The daily dose of acetaminophen is 1.575 grams if the two cold medicines are used together, and more than 2 grams if taken four times a day.
Medicine is really a double-edged sword, can heal and save, but also harm. Take medicine also want very careful, take medicine before must see the instruction book more, will eat according to the dose. Be sure not to can ask the doctor of specialized subject.