What is Xanax?
Xanax is a brand of Alprazolam, a type of benzodiazepine which works by decreasing abnormal excitement in the brain. The Food and Drug Administration (FDA) approved it in October 1981. Benzodiazepines act on the brain and central nervous system (CNS) to produce a calming effect.
Xanax is a federal controlled substance (C-IV) because it can be abused or lead to dependence. Keep this medicine in a safe place to prevent misuse and abuse. Selling or giving away Xanax may harm others, and is against the law. Tell your healthcare provider if you have abused or been dependent on alcohol, prescription medicines or street drugs.
How long does Xanax last?
According to the official answer provided by drugs.com , one dose of Xanax can last anywhere from 31 hours to 134.5 hours (5.6 days) in the body, depending on factors related to the individual who took it. However, the calming, relaxing, and sedative effects of Xanax usually wears off within about eight to twelve hours.
Xanax is taken by mouth and quickly absorbed into the bloodstream. Effects should be noticed within an hour and the medicine reaches peak concentrations in the body after one to two hours. People who take Xanax regularly can build up a tolerance to it and effects, such as a feeling of calm or sedation, may take longer to develop or not be felt as strongly as before.
Xanax is usually prescribed three times a day because its effects in the body (calming, sedation, relaxing) tend to wear off within eight hours for most people. However, one dose of Xanax remains detectable in the body for two to five days – the exact length of time depends on several factors specific to the individual who took the dose.
What factors determine the half-life of Xanax?
Factors that determine how long a dose of Xanax will persist in the body for include:
- A person’s age: Xanax lasts for a longer time in elderly people. The average half-life in the elderly is 16.3 hours, compared to 11.2 hours in younger, healthy adults
- Weight: Xanax lasts for a longer time in heavier people, because obesity makes it harder for your body to break down Xanax. The average half-life in people who are overweight/obese is 21.8 hours, compared to 11.2 hours in young, healthy adults
- Ethnicity: Xanax lasts for a longer time in Asian people. The average half-life in Asian people is 14 hours, compared to 11.2 hours in Caucasians
- Metabolism: People who exercise a lot or who have a faster metabolism clear Xanax faster than those who don’t exercise or do any physical activity. The half-life of Xanax is shorter in these people
- Liver function: Xanax lasts for a longer time in people with poor liver function. The average half-life in people with alcoholic liver disease is 19.7 hours, compared to 11.2 hours in young, healthy adults
- Dosage: It takes longer for your body to metabolize higher dosages of Xanax. The bigger the dose of Xanax, the longer the half-life
- Length of time taking Xanax: If you take Xanax regularly, then you will have a higher concentration in your bloodstream and it will take longer to fully eliminate it all. But because you have built up a tolerance to the drug, you may not necessarily feel its effects for longer
- Interacting medications: Xanax lasts longer when it is taken with drugs that inhibit CYP3A4 (eg, erythromycin, ketoconazole, nefazodone, oral contraceptives), one of its metabolizing pathways. Other drugs (such as carbamazepine, St John’s wort), may decrease the half-life of Xanax
- Smoking: The half-life of Xanax may be reduced by up to 50% in smokers compared to nonsmokers. This means that smokers metabolize Xanax more quickly than nonsmokers
- Alcohol: Alcohol can increase the effects and half-life of Xanax, and can lead to dangerous side effects which could be fatal.
How long does Xanax stay in your system?
Studies have shown that the half-life of Xanax ranges from 6.3 to 26.9 hours. It is important to realize that half-life is a figure that is an estimate of the time it takes for the concentration or amount in the body of that drug to be reduced by exactly one half (50%). After four to five half-lives, 97% of a drug has cleared from the body, and the drug is no longer considered to be having any effect. However, this does not mean that it won’t be detectable by a drug test, as this depends on how specific and sensitive the drug test is.
If we use the average half-life of Xanax, which is 11.2 hours, then the following is estimated for a 1mg dose of Xanax:
- 11.2 hours after administration, 0.5mg remains
- 22.4 hours minutes after administration, 0.25mg remains
- 33.6 hours after administration, 0.125mg remains
- 44.8 hours after administration, 0.063mg remains
- 56 hours after administration, 0.0315mg remains.
In theory, we can see that after 56 hours (2.3 days), almost all the original Xanax dose (slightly less than 97%) has been eliminated in people whose Xanax half life is 11.2 hours. However, in some people, the half-life of Xanax is 26.9 hours. In these people, it will take approximately 134.5 hours (5.6 days) for almost 97% of a dose of Xanax to be eliminated.
Xanax Safety Information
Xanax may increase the risk of serious or life-threatening breathing problems, sedation, or coma if used along with certain medications. Tell your doctor if you are taking or plan to take certain opiate medications for cough such as codeine (in Triacin-C, in Tuzistra XR) or hydrocodone (in Anexsia, in Norco, in Zyfrel) or for pain such as codeine (in Fiorinal), fentanyl (Actiq, Duragesic, Subsys, others), hydromorphone (Dilaudid, Exalgo), meperidine (Demerol), methadone (Dolophine, Methadose), morphine (Astramorph, Duramorph PF, Kadian), oxycodone (in Oxycet, in Percocet, in Roxicet, others), and tramadol (Conzip, Ultram, in Ultracet). Your doctor may need to change the dosages of your medications and will monitor you carefully. If you take Xanax with any of these medications and you develop any of the following symptoms, call your doctor immediately or seek emergency medical care immediately: unusual dizziness, lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness. Be sure that your caregiver or family members know which symptoms may be serious so they can call the doctor or emergency medical care if you are unable to seek treatment on your own.
Xanax may be habit forming. Do not take a larger dose, take it more often, or for a longer time than your doctor tells you to. Tell your doctor if you have ever drunk large amounts of alcohol, if you use or have ever used street drugs, or have overused prescription medications. Do not drink alcohol or use street drugs during your treatment. Drinking alcohol or using street drugs during your treatment with Xanax also increases the risk that you will experience these serious, life-threatening side effects. Also tell your doctor if you have or have ever had depression or another mental illness.
Xanax may cause a physical dependence (a condition in which unpleasant physical symptoms occur if a medication is suddenly stopped or taken in smaller doses), especially if you take it for several days to several weeks. Do not stop taking this medication or take fewer doses without talking to your doctor. Stopping Xanax suddenly can worsen your condition and cause withdrawal symptoms that may last for several weeks to more than 12 months. Your doctor probably will decrease your Xanax dose gradually. Call your doctor or get emergency medical treatment if you experience any of the following symptoms: unusual movements; ringing in your ears; anxiety; memory problems; difficulty concentrating; sleep problems; seizures; shaking; muscle twitching; changes in mental health; depression; burning or prickling feeling in hands, arms, legs or feet; seeing or hearing things that others do not see or hear; thoughts of harming or killing yourself or others; overexcitement; or losing touch with reality.