Cindy asked
How fast does Xanax (alprazolam) work? What is the onset of action?
Answer
Xanax (alprazolam) has a relatively fast onset of action compared to other benzodiazpine medications. Xanax will begin to work within 15 to 30 minutes are taking the medication by mouth. Maximum effect from Xanax occurs around 1 to 2 hours after dosing, as this is when peak blood levels of the drug are seen in the body.
Xanax also has a short half-life when compared to other benzodiazepines. In healthy individuals, the average half-life is around 11.2 hours. The half-life is prolonged in the elderly and in those with liver disease. Due to the short half life of the drug, it is often noted as being particularly difficult to discontinue if you have been taking it for long periods of time. Generally, a cautious taper protocol is necessary.
It should be noted that Xanax is also available and administered via IV, although this is mostly done in hospitals. IV administration of Xanax has a much faster onset of action (~1-2 minutes) and studies have shown maximum sedative effects occur less than 30 minutes after IV administration, more than twice as fast than when taken by mouth.
Summary
- When taken by mouth, Xanax beings to work in 15 to 30 minutes.
- When administered via IV, Xanax begins to work in 1 to 2 minutes.
- Maximum sedative effect and peak concentrations of Xanax are reached 1 to 2 hours after oral administration.
- Maximum sedative effect and peak concentrations of Xanax are reached about 30 minutes after IV administration.
