Mixing Alcohol With Medicines – You’ve probably seen this warning on medicines you’ve taken. The danger is real. Mixing alcohol with certain medications can cause nausea and vomiting, headaches, drowsiness, fainting, or loss of coordination. It also can put you at risk for internal bleeding, heart problems, and difficulties in breathing.
In addition to these dangers, alcohol can make a medication less effective or even useless, or it may make the medication harmful or toxic to your body. Some medicines that you might never have suspected can react with alcohol, including many medications which can be purchased “over-the-counter”—that is, without a prescription.
Even some herbal remedies can have harmful effects when combined with alcohol. This pamphlet lists medications that can cause harm when taken with alcohol and describes the effects that can result. The list gives the brand name by which each medicine is commonly known (for example, Benadryl®) and its generic name or active ingredient (in Benadryl®, this is diphenhydramine).
- 1 Why do drugs react with alcohol?
- 2 What are the harmful effects of mixing alcohol?
- 3 Is it safe to take drugs and alcohol together or combining two or more drugs?
- 4 Can you drink alcohol on drugs?
- 4.1 Can I drink alcohol with antibiotics?
- 4.2 Is alcohol a good painkiller?
- 4.3 When two drugs affect each other?
What happens when you mix alcohol with other drugs?
Alcohol is a drug. When you take alcohol with another drug, there is interaction in your body where one drug alters the other drug’s effects. Mixing alcohol with other drugs can be unpredictable and dangerous. If you take alcohol with other drugs, the effects could be nausea, illness or death.
Why do drugs react with alcohol?
Alcohol and CYP Enzymes – Cytochrome P450 (CYP) enzymes are a group of enzymes found throughout the body, primarily in the liver. They help to break down drugs so they can be excreted from the body. There are many different types of enzymes with different names, indicated by letters and numbers.
- For example, the common pain and fever reliever acetaminophen ( Tylenol ) is also metabolized by CYP2E1. When alcohol and acetaminophen are combined in alcohol users that drink frequently each day, liver toxicity, and even liver failure, can occur, due to formation of dangerous acetaminophen by-products.
- Ask a healthcare provider if this medicine is safe to use if you drink alcohol daily or you’ve ever had cirrhosis of the liver.
Alcohol is also known to strongly inhibit (or block) an enzyme in the liver known CYP2C9. When alcohol is consumed with other drugs that primarily use this enzyme for breakdown and excretion, blood levels of the other drug may theoretically increase, leading to increased side effects and toxicity.
- One example is the drug interaction between warfarin and alcohol, which could increase bleeding risk.
- Always check with your pharmacist, doctor or other healthcare provider to see if these types of enzyme interactions are of concern between your medications.
What are the harmful effects of mixing alcohol?
Congeners & Hangovers – Different types of alcohol have different congeners. Congeners are chemicals in alcohol that are added or created during fermentation and are often linked to symptoms of hangovers. Congeners such as methanol and furfural may be found in some, but not all, types of alcohol.
Is it safe to drink alcohol while taking ibuprofen?
The bottom line. Most people can drink a small amount of alcohol if they’ve taken ibuprofen. But if you heavily drink, you may have a higher risk of side effects. Serious side effects of mixing ibuprofen and alcohol include GI bleeding, kidney or liver problems, and heart problems.
Is it safe to take drugs and alcohol together or combining two or more drugs?
Polysubstance Use Facts The use of more than one drug, also known as polysubstance use, is common. This includes when two or more are taken together or within a short time period, either intentionally or unintentionally.
- Intentional polysubstance use occurs when a person takes a drug to increase or decrease the effects of a different drug or wants to experience the effects of the combination.
- Unintentional polysubstance use occurs when a person takes drugs that have been mixed or cut with other substances, like fentanyl, without their knowledge.
- Whether intentional or not, mixing drugs is never safe because the effects from combining drugs may be stronger and more unpredictable than one drug alone, and even deadly.
The dangers of polysubstance use also apply to prescription drugs. Always let your doctor know what drugs you are taking to prevent any adverse reactions with newly prescribed medications. Never take pills that did not come from a pharmacy and weren’t prescribed to you.250+ —The number of American lives lost to drugs every day.1 50% — In 2019, nearly half of drug overdose deaths involved multiple drugs.2 Examples of stimulants: ecstasy (MDMA), cocaine, methamphetamines, amphetamines (speed) Stimulants (also known as uppers) can increase your heart rate and blood pressure to dangerous levels and increase your risk of several serious health problems. Combining stimulants may even directly or indirectly increase your risk of:
- Brain injury
- Liver damage
- Heart attack
Signs of use/overdose 3,4 that may occur when mixing stimulants:
- Fast/troubled breathing
- Increased body temperature
- Nausea or vomiting
- Chest pain
- Seizures or tremors
Examples of depressants: opioids (heroin, morphine, oxycodone, hydrocodone, fentanyl), benzodiazepines Depressants (also known as downers) can slow down your breathing and increase your risk of several adverse health outcomes. Combining depressants can also directly or indirectly increase your risk of:
- Damage to the brain and other organs
Signs of use/overdose 5,6 when mixing depressants:
- Slow breathing
- Weak pulse
- Altered mental status or confusion
- Passing out
Mixing stimulants and depressants Mixing stimulants and depressants doesn’t balance or cancel them out. In fact, the results of combining drugs are unpredictable, often modifying or even masking the effects of one or both drugs. This may trick you into thinking that the drugs are not affecting you, making it easier to overdose. Drinking alcohol while using other drugs Drinking alcohol while using other drugs isn’t safe. Alcohol is a depressant with similar effects to other downers. Mixing alcohol with other drugs can increase your risk of overdose and serious damage to the brain, heart, and other organs.
- Call 911 Immediately.*
- Administer, if available. **
- Try to keep the person awake and breathing.
- Lay the person on their side to prevent choking.
- Stay with the person until emergency assistance arrives.
*Most states have laws that may protect a person who is overdosing or the person who called for help from legal trouble. **Naloxone is a life-saving medication that can reverse the effects of opioid overdose and save lives. It is available in all 50 states and can be purchased from a local pharmacy without a prescription in most states.
- NCHS, National Vital Statistics System. Estimates for 2020 are based on provisional data. Estimates for 2015-2019 are based on final data (available from: ).
- O’Donnell J, Gladden RM, Mattson CL, Hunter CT, Davis NL. Vital Signs: Characteristics of Drug Overdose Deaths Involving Opioids and Stimulants — 24 States and the District of Columbia, January–June 2019. MMWR Morb Mortal Wkly Rep 2020; 69:1189–1197. DOI:
- NIDA.2020, October 7. Cocaine. Retrieved from on 2021, March 11
- NIDA.2019, May 16. Methamphetamine DrugFacts. Retrieved from on 2021, March 11
- SAMHSA.2020, August 19. Opioid Overdose. Retrieved from
- National Institute on Drug Abuse. (n.d.). Heroin (smack, junk) facts. Easy-to-Read Drug Facts. Retrieved from
Does alcohol affect absorption of drugs?
Abstract – Ethanol and drugs can affect each other’s absorption, distribution, metabolism, and excretion. When ingested together, ethanol can increase drug absorption by enhancing the gastric solubility of drugs and by increasing gastrointestinal blood flow.
However, high concentrations of ethanol induce gastric irritation causing a pyloric spasm which in turn may delay drug absorption and/or reduce bioavailability. The ‘quality’ of the alcoholic beverage, independent of its ethanol content, can contribute to altered absorption of a drug. Ethanol is not bound to plasma proteins extensively enough to modify drug distribution.
However, serum albumin levels in chronic alcoholics may be abnormally low so that some drugs, e.g. diazepam, have an increased volume of distribution. In addition to the amount ingested, the duration of regular intake determines the effect of ethanol on drug metabolism.
- Acute intake of ethanol inhibits the metabolism of many drugs but long term intake of ethanol at a high level (greater than 200g of pure ethanol per day) can induce liver enzymes to metabolise drugs more efficiently.
- At the present time there are no accurate means, with the possible exception of liver biopsy, to clinically predict the capacity of an alcoholic to metabolise drugs.
Several drugs can inhibit the metabolism of ethanol at the level of alcohol dehydrogenase. Individual predisposition determines the severity of this drug-ethanol interaction. During its absorption phase, ethanol inhibits the secretion of antidiuretic hormone and is also able to induce increased excretion of a drug through the kidneys.
However, chronic alcoholics with water retention may show reduced excretion of drugs via this route. At the pharmacodynamic level, ethanol can enhance the deleterious effects of sedatives, certain anxiolytics, sedative antidepressants and antipsychotics and anticholinergic agents, on performance. Mechanisms of lethal interactions between moderate overdoses of ethanol and anxiolytics/opiates/sedatives are poorly understood.
On the other hand, certain peptides, ‘nonspecific’ stimulants, dopaminergic agents and opiate antagonists can antagonise alcohol-induced inebriation to a significant degree.
What happens if you take 4 pills at once?
If you take more than one medicine, it is important to take them carefully and safely. Some medicines can interact and cause side effects. It can also be hard to keep track of when and how to take each medicine. Here are tips to help you keep track of your medicines and take them as directed.
You may take more than one medicine to treat a single condition. You may also take different medicines to treat more than one health problem. For example, you may take a statin to lower your cholesterol, and a beta-blocker to control your blood pressure. Older adults often have more than one health condition.
So they are more likely to take several medicines. The more medicines you take, the more you need to use them carefully. There are several risks when taking multiple medicines.
You may be more likely to have side effects. Because most medicines can have side effects, the more medicines you take, the more likely you will have side effects. Taking certain medicines can also increase the risk for falls,You are at higher risk for drug interactions. An interaction is when one medicine affects how another medicine works. For example, taken together, one medicine may make the other medicine stronger. Medicines can also interact with alcohol and even some foods. Some interactions can be serious, even life threatening.You may find it hard to keep track of when to take each medicine. You even may forget which medicine you have taken at a certain time.You may take a medicine you do not need. This may be more likely to happen if you see more than one health care provider. You may be prescribed different medicines for the same problem.
Certain people are more likely to have problems from taking multiple medicines:
People who are prescribed 5 or more medicines. The more medicines you take, the higher the chance of interactions or side effects. You may also find it hard to remember all possible drug interactions. People who take medicines prescribed by more than one provider. One provider may not know that you are taking medicines another provider has given you. Older adults. As you age, your body processes medicines differently. For instance, your kidneys may not work as well as they used to. This can mean that more medicine stays in your body for longer. This can lead to dangerous levels of medicines in your system. People in the hospital. When you are in the hospital, you will likely see new providers who are not familiar with your health history. Without this knowledge, they may prescribe a medicine that may interact with medicines you already take.
These suggestions can help you take all of your medicines safely:
Keep a list of all medicines you take. Your list should include all prescription and over-the-counter (OTC) medicines, OTC medicines include vitamins, supplements, and herbal products. Keep a copy of the list in your wallet and at home.Review your medicine list with your providers and pharmacists. Discuss the list with your provider each time you have an appointment. Ask your provider if you still need to take all of the medicines on your list. Also ask if any of the dosages should be changed. Make sure you give all of your providers a copy of your medicine list. Ask questions about any new drugs you are prescribed. Make sure you understand how to take them. Also ask if a new medicine could interact with any of the medicines or supplements you are already taking.Take your medicines exactly as your provider tells you. If you have questions about how or why to take your medicine, ask your provider. Do not skip doses, or stop taking your medicines.If you notice side effects, tell your provider, Do not stop taking your medicines unless your provider tells you to. Keep your medicines organized, There are many ways to keep track of your medicines. A pill organizer may help. Try one or more methods and see what works for you.If you have a hospital stay, bring your medicine list with you. Talk with your provider about medicine safety while you are in the hospital.
Call if you have questions or you are confused about the directions for your medicine. Call if you have any side effects from your medicines. Do not stop taking any medicine unless your provider tells you to stop. Agency for Healthcare Research and Quality website.20 tips to help prevent medical errors: patient fact sheet.
www.ahrq.gov/patients-consumers/care-planning/errors/20tips/index.html, Updated November 2020. Accessed August 11, 2022. National Institute on Aging website. www.nia.nih.gov/health/safe-use-medicines-older-adults, Updated June 26, 2019. Accessed August 11, 2022. Ryan R, Santesso N, Lowe D, et al. Interventions to improve safe and effective medicines use by consumers: an overview of systematic reviews.
Cochrane Database Syst Rev,2014;29(4):CD007768. PMID: 24777444 pubmed.ncbi.nlm.nih.gov/24777444/, US Food & Drug Administration website. Ensuring safe use of medicine. www.fda.gov/drugs/buying-using-medicine-safely/ensuring-safe-use-medicine, Updated September 12, 2016.
Accessed August 11, 2022. US Department of Health and Human Services website. Healthy living: use medicines safely: the basics. health.gov/myhealthfinder/healthy-living/safety/use-medicines-safely#the-basics-tab, Updated July 20, 2022. Accessed August 11, 2022. US Department of Health and Human Services website.
Healthy living: use medicines safely: take action. health.gov/myhealthfinder/healthy-living/safety/use-medicines-safely#take-action-tab, Updated July 20, 2022. Accessed August 11, 2022. Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA.
Can you drink alcohol while taking paracetamol?
Can I drink alcohol while taking paracetamol? Drinking a small amount of alcohol while taking paracetamol is usually safe. Try to keep to the recommended guidelines of no more than 14 units of alcohol a week. A standard glass of wine (175ml) is 2 units.
What are 4 negative effects of alcohol?
Long-Term Health Risks – Over time, excessive alcohol use can lead to the development of chronic diseases and other serious problems including:
- High blood pressure, heart disease, stroke, liver disease, and digestive problems.6,16
- of the breast, mouth, throat, esophagus, voice box, liver, colon, and rectum.6,17
- Weakening of the immune system, increasing the chances of getting sick.6,16
- Learning and memory problems, including dementia and poor school performance.6,18
- Mental health problems, including depression and anxiety.6,19
- Social problems, including family problems, job-related problems, and unemployment.6,20,21
- Alcohol use disorders, or alcohol dependence.5
By not drinking too much, you can reduce the risk of these short- and long-term health risks.
- Centers for Disease Control and Prevention., Accessed April 19, 2022.
- Esser MB, Leung G, Sherk A, Bohm MB, Liu Y, Lu H, Naimi TS., JAMA Netw Open 2022;5:e2239485.
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- U.S. Department of Agriculture and U.S. Department of Health and Human Services.9th Edition, Washington, DC; 2020.
- Esser MB, Hedden SL, Kanny D, Brewer RD, Gfroerer JC, Naimi TS., Prev Chronic Dis 2014;11:140329.
- World Health Organization., Geneva, Switzerland: World Health Organization; 2018.
- Alpert HR, Slater ME, Yoon YH, Chen CM, Winstanley N, Esser MB., Am J Prev Med 2022;63:286–300.
- Greenfield LA., Report prepared for the Assistant Attorney General’s National Symposium on Alcohol Abuse and Crime. Washington, DC: U.S. Department of Justice, 1998.
- Mohler-Kuo M, Dowdall GW, Koss M, Wechsler H., Journal of Studies on Alcohol 2004;65(1):37–45.
- Abbey A., J Stud Alcohol Suppl 2002;14:118–128.
- Kanny D, Brewer RD, Mesnick JB, Paulozzi LJ, Naimi TS, Lu H., MMWR 2015;63:1238-1242.
- Naimi TS, Lipscomb LE, Brewer RD, Colley BG., Pediatrics 2003;11(5):1136–1141.
- Wechsler H, Davenport A, Dowdall G, Moeykens B, Castillo S., JAMA 1994;272(21):1672–1677.
- Kesmodel U, Wisborg K, Olsen SF, Henriksen TB, Sechler NJ., Alcohol & Alcoholism 2002;37(1):87–92.
- American Academy of Pediatrics, Committee on Substance Abuse and Committee on Children with Disabilities.2000., Pediatrics 2000;106:358–361.
- Rehm J, Baliunas D, Borges GL, Graham K, Irving H, Kehoe T, et al., Addiction.2010;105(5):817-43.
- International Agency for Research on Cancer. Personal Habits and Indoor Combustions: A Review of Human Carcinogens, Volume 100E 2012. Available from:,
- Miller JW, Naimi TS, Brewer RD, Jones SE., Pediatrics.2007;119(1):76-85.
- Castaneda R, Sussman N, Westreich L, Levy R, O’Malley M., J Clin Psychiatry 1996;57(5):207–212.
- Booth BM, Feng W., J Behavioral Health Services and Research 2002;29(2):157–166.
- Leonard KE, Rothbard JC., J Stud Alcohol Suppl 1999;13:139–146.
How alcohol affects the brain?
Image Diffusion tensor imaging (DTI) of fiber tracks in the brain of a 58-year-old man with alcohol use disorder. DTI maps white-matter pathways in a living brain. Image courtesy of Drs. Adolf Pfefferbaum and Edith V. Sullivan. Alcohol interferes with the brain’s communication pathways and can affect the way the brain looks and works.
Can you drink alcohol on drugs?
Alcohol is recognised as a ‘psychoactive substance’ by the World Health Organization, because of how it affects your brain, the way you think and feel, and your health.1 Illegal drugs are psychoactive substances too and have a wide range of different dangerous health effects on their own.
If you drink alcohol and take drugs at the same time or close together, it can have serious harmful effects as the different substances interact with each other and with your body. The effects can even be fatal. The best advice is not to take illegal drugs at all. If you do drink alcohol, you should never combine it with illegal drugs, and always stick to the UK Chief Medical Officers’ (CMOs) low risk drinking guidelines,
If you or someone else needs urgent help after taking drugs or drinking, call 999 for an ambulance. Tell the crew everything you know. It could save their life. Alcohol is a depressant, which means it alters the delicate balance of chemicals in your brain 2 and interferes with processes in your central nervous system.3 All illegal drugs have different effects of their own, which are dangerous in their own right – including depressants like heroin and tranquilisers.
- If you have alcohol with another depressant it can multiply the effect – putting your body at increased risk.
- Some other illegal drugs have a ‘stimulant’ effect, like cocaine, ecstasy (MDMA) and other amphetamines.
- Combining a stimulant with alcohol can cause additional stress on your body, which can be dangerous.4 If you’re under the influence of drugs you are less likely to make considered decisions about how much alcohol you drink – these lowered inhibitions put you at risk of acute alcohol poisoning,
And with no quality control in the world of illegal drugs, you can never be sure of exactly what you’re taking – they can be mixed or contaminated with other harmful substances. Adding alcohol into the mix adds another risk factor to what is already a potentially lethal cocktail.
- Here are some facts about what can happen when you mix certain illegal drugs with alcohol.
- The UK Chief Medical Officers’ low risk drinking guidelines advise it’s safest for both men and women to drink no more than 14 units a week, spread over three or more days with several drink-free days, and no bingeing.
Drinking more than this puts you at greater risk of heart disease, seven types of cancer and other health problems.
Can I drink alcohol with antibiotics?
Avoid Alcohol While Taking Antibiotics – Drinking alcohol while taking antibiotics can be risky. Not only can alcohol interact badly with some medications and cause severe side effects, it can also potentially interrupt the natural healing process. Alcohol should be avoided until the regimen of antibiotics is completed and your body receives adequate rest and nutrition.
Can you drink alcohol at night if you take Xanax in the morning?
Because of the heightened side effects from the combination, healthcare providers don’t recommend drinking any amount of alcohol while you’re taking benzodiazepines.
Can you take painkillers with alcohol?
Prescription painkillers – Alcohol must be avoided while on a course of prescription-only painkillers, such as tramadol, gabapentin and codeine and other morphine-like drugs. Consuming alcohol alongside these medications can be dangerous – leading to severe drowsiness and other side effects, such as nausea.4 Visit the NHS website for more information about how different types of painkillers can interact with alcohol.
Is it okay to take painkillers after drinking?
WHY YOU SHOULD NEVER MIX ALCOHOL WITH YOUR PAIN MEDICATION – San Diego | API Many common pain medications, both prescription and over-the-counter, come with a familiar warning label: “Do not mix with alcohol.” Whether you take painkillers on a regular basis or you need them to deal with short-term discomfort, it’s crucial to always take this warning seriously.
- On its own, alcohol can impact the body in many significant ways, altering your brain chemistry and depressing your nervous system.
- But drinking alcohol when you’re also taking pain medication can intensify its impact and cause dangerous, unexpected side effects, including organ damage, loss of consciousness, and even death.
Mixing alcohol with over-the-counter pain medication When you’re suffering from a headache or a strained muscle, fast pain relief can often be found in your medicine cabinet – no prescription necessary. While taking over-the-counter pain meds usually carries an extremely low degree of risk, combining them with alcohol can cause serious adverse reactions.
Here are some of the more common over-the-counter pain medications that you should avoid mixing with alcohol: When used as recommended, Tylenol is a safe, effective pain reliever. But taking it in large doses or mixing a regular dose with alcohol can lead to irreversible liver damage. Products containing ibuprofen, such as Motrin, Midol, or Advil, can cause stomach upset even when taken as directed.
Drinking alcohol with these anti-inflammatory drugs in your system can increase your risk of stomach problems, even causing gastrointestinal bleeding. Many people take a low dose of aspirin everyday to ward off the effects of heart disease or stroke. But regular use of aspirin and alcohol together can actually increase your risk of internal bleeding, stroke, or kidney failure.
- Mixing alcohol with prescription painkillers While it’s undoubtedly dangerous to combine over-the-counter pain meds with alcohol, drinking while you’re taking prescription opioid painkillers can be deadly.
- According to the National Institute on Drug Abuse, overdose deaths involving prescription opioids have increased dramatically in recent years, with over 17,000 Americans losing their lives to a prescription painkiller overdose in 2017.
And alcohol consumption significantly raises your risk of an opioid overdose. Prescription painkillers, such as Vicodin, Percocet, or Oxycontin, work by blocking pain messages that are sent from your body to your brain. They also produce a general calming effect, including slowed breathing, sleepiness, and deep relaxation.
Alcohol can enhance these effects, causing a more intense high, but also making you extremely drowsy. As a result, your breathing and heart rates slow down, your oxygen levels plummet, and your risk of slipping into a coma increases. If this happens, it’s critical to receive emergency medical care as soon as possible; without enough oxygen, you could suffer serious brain damage, organ failure, or death.
How to avoid the dangerous side effects of mixing alcohol with pain medication The best way to avoid serious illness or injury due to drug and alcohol interactions is to abstain from drinking alcohol whenever you’re taking pain medication, no matter how small the dosage.
- Even a single social drink could put your health at risk.
- However, it’s always best to consult with your doctor or pharmacist for more specific instructions on alcohol consumption and medication management.
- And if you have a history of alcohol abuse or drug addiction, it’s important to tell your doctor about it.
They can help you avoid a potentially deadly interaction and steer you clear of addictive pain medications that could lead you down a dangerous path. Conquer your drug and alcohol addiction at Alvarado Parkway Institute If you’re having a hard time controlling your alcohol intake, or you’re struggling to stop taking painkillers, you don’t have to do it alone.
- Alvarado Parkway Institute is here to help you conquer your addictions so you can live a sober, healthy life.
- Both our inpatient and outpatient treatment programs are designed to help you achieve stability, receive support, and learn coping strategies to avoid relapse.
- For more information on how Alvarado Parkway Institute can help you on the road to recovery from drug and alcohol addiction, call us at (619) 485-1432.
: WHY YOU SHOULD NEVER MIX ALCOHOL WITH YOUR PAIN MEDICATION – San Diego | API
Is alcohol a good painkiller?
People have used alcohol to relieve pain since ancient times. Laboratory studies confirm that alcohol does indeed reduce pain in humans and in animals. Moreover, recent research suggests that as many as 28 percent of people experiencing chronic pain turn to alcohol to alleviate their suffering.
What is it called when two drugs should not be taken together?
A contraindication is a specific situation in which a drug, procedure, or surgery should not be used because it may be harmful to the person. There are two types of contraindications:
Relative contraindication means that caution should be used when two drugs or procedures are used together. (It is acceptable to do so if the benefits outweigh the risk.)Absolute contraindication means that event or substance could cause a life-threatening situation. A procedure or medicine that falls under this category must be avoided.
Some treatments may cause unwanted or dangerous reactions in people with allergies, high blood pressure, or pregnancy. For example, isotretinoin, a drug used to treat acne, is absolutely contraindicated in pregnancy due to the risk of birth defects. Certain decongestants are contraindicated in people with high blood pressure and should be avoided.
- Many medicines should not be used together by the same person.
- For instance, a person who takes warfarin to thin the blood should not take aspirin, which is also a blood thinner.
- This is an example of a relative contraindication.
- Updated by: Linda J.
- Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA.
Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
When two drugs affect each other?
How do drug interactions occur? – Drug interactions can occur in several ways:
- A pharmacodynamic interaction occurs when two drugs given together act at the same or similar receptor site and lead to a greater (additive or synergistic) effect or a decreased (antagonist) effect. For example, when chlorpromazine, sometimes used to help prevent nausea and vomiting, and haloperidol, an antipsychotic medication for schizophrenia, are given together there may be a greater risk for causing a serious, possibly fatal irregular heart rhythm.
- A pharmacokinetic interaction may occur if one drug affects another drug’s absorption, distribution, metabolism, or excretion. Examples can help to explain these complicated mechanisms:
- Absorption: Some drugs can alter the absorption of another drug into your bloodstream. For example, calcium can bind with some medications and block absorption. The HIV treatment dolutegravir ( Tivicay ) should not be taken at the same time as calcium carbonate (Tums, Maalox, others), because it can lower the amount of dolutegravir absorbed into the bloodstream and reduce its effectiveness in treating HIV infection. Dolutegravir should be taken 2 hours before or 6 hours after medications that contain calcium or other minerals to help prevent this interaction. In the same manner, many drugs cannot be taken with milk or dairy products because they will bind with the calcium. Drugs that affect stomach or intestine motility, pH, or natural flora can also lead to drug interactions.
- Distribution: Protein-binding interactions can occur when two or more highly protein-bound drugs compete for a limited number of binding sites on plasma proteins. One example of an interaction is between fenofibric acid (Trilipix), used to lower cholesterol and triglycerides in the blood, and warfarin, a common blood thinner to help prevent clots. Fenofibric acid can increase the effects of warfarin and cause you to bleed more easily.
- Metabolism: Drugs are usually eliminated from the body as either the unchanged (parent) drug or as a metabolite that has been changed in some way. Enzymes in the liver, usually the CYP450 enzymes, are often responsible for breaking down drugs for elimination from the body. However, enzyme levels may go up or down and affect how drugs are broken down. For example, using diltiazem (a blood pressure medication) with simvastatin (a medicine to lower cholesterol) may elevate the blood levels and side effects of simvastatin, Diltiazem can inhibit (block) the CYP450 3A4 enzymes needed for the breakdown (metabolism) of simvastatin. High blood levels of simvastatin can lead to serious liver and muscle side effects.
- Excretion: Some nonsteroidal antiinflammatory drugs ( NSAIDs ), like indomethacin, may lower kidney function and affect the excretion of lithium, a drug used for bipolar disorder. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications together.
How long should I wait to take medicine after drinking alcohol?
If the amount of alcohol used would be classified as binge drinking, it may take 18 to 24 hours to be alcohol-free. It may take your liver a while to recover even after alcohol is fully removed from your body, so it is safest to wait at least 72 hours after drinking to take Tylenol.