Login ». As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
Thanks for visiting. Don't miss your FREE gift. Sign up to get tips for living a healthy lifestyle, with ways to fight inflammation and improve cognitive health , plus the latest advances in preventative medicine, diet and exercise , pain relief, blood pressure and cholesterol management, and more. Get helpful tips and guidance for everything from fighting inflammation to finding the best diets for weight loss Stay on top of latest health news from Harvard Medical School.
Recent Blog Articles. Health news headlines can be deceiving. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors. When doctors write prescriptions for medications, they don't just jot down the name of a drug and send their patients off to the pharmacy. Included on the prescription are details about how much of the medication to take at one time the dose and at what intervals.
These instructions, which are very important for making certain the drug is effective and safe, are based in part on the half-life of the medication being prescribed. As a patient, it rarely is necessary to know the half-life of a drug you are taking. But it can help to understand what this term means and how it might affect you during the time you're on the drug. A medication's biological half-life refers simply to how long it takes for half of the dose to be metabolized and eliminated from the bloodstream.
Or, put another way, the half-life of a drug is the time it takes for it to be reduced by half. For example, the half-life of ibuprofen the active ingredient in pain and fever relievers such as Advil and Motrin is about two hours. It's important to note that the expected half-life of a drug varies from person to person, depending on factors such as age, weight, genetics, and even specific health issues.
For example, the half-life of acetaminophen the active ingredient in Tylenol , can be significantly affected by a person's liver function, since acetaminophen is primarily processed through the liver.
The goal of any medication that will need to be taken on an ongoing basis, such as an antidepressant, is to get it to a "steady state"—in other words, to the point at which the amount that goes into the body is equal to the amount that's eliminated.
No matter what the half-life of a medication is, it takes about four times that amount of time for the concentration of the drug to reach a steady state in the body. For OTC ibuprofen, this equates to a maximum of 6 pills per day.
Additionally, avoid taking ibuprofen for longer than 10 days, unless directed to do so by your doctor. Because of this, it may be helpful to take ibuprofen with food or milk. Ibuprofen can be given to children as a liquid solution, chewable tablet, or pill. If your child needs to take ibuprofen, ask their pediatrician for the recommended dosage and how often it needs to be taken. While ibuprofen is generally safe, it may not be suitable for everyone.
Ibuprofen can increase the risk of gastrointestinal bleeding , heart attack , and stroke. Taking too much ibuprofen can be dangerous. If you experience any of the above symptoms, seek immediate medical attention. In addition to ibuprofen, aspirin and naproxen Aleve are also available over the counter. While the amount of time it takes for ibuprofen to work can vary, it usually takes about half an hour to start feeling symptom relief. Adults can take a dose of OTC ibuprofen every 4 to 6 hours.
When taking ibuprofen, be sure not to exceed the maximum daily dosage or to take it for more than 10 days. Dosing for children depends on body weight. Ibuprofen may not be recommended if you have certain health conditions or are taking specific medications. The half-life of a given drug is usually a pretty reliable indicator of how long it lasts in our system. In most cases, a drug is completely eliminated within 5 to 6 half-lives 1.
The half-life of ibuprofen is around 2 to 4 hours 2 , which means that it will be eliminated within hours for most individuals. Ibuprofen is metabolized and eliminated faster in pediatric patients compared to adults. The prescribing information for one ibuprofen product Caldolor reports a half-life of around 1.
This means that it will be completely eliminated in around 12 hours for this age group. The half-life of ibuprofen is significantly prolonged in individuals with liver impairment with most studies specifically referring cirrosis. It should be noted that while ibuprofen lasts in your system for hours for most, the actual duration of action is far shorter.
0コメント