How long shoul i wait before taking 20 mgs of zolpidem after taking3 mgs of xanax (alprazolam)?

Careful mixing drugs: That is a high dose of Xanax (alprazolam). I would advise extreme caution. Immediately stop and seek medical attention urgently. Please do NOT mix these two medication. Talk to your doctor about taking these two meds together and risk of side effects.

Addiction: I am going to speak frankly. You are taking drugs in combination and at such high doses that you must have developed tolerance and addiction. They are not working for you any more. Ever increasing these drugs will not in any way bring you peaceful restorative sleep or any peace and happiness in life. It is time to get your brain clear of these chemicals and to really treat the underlying condition

Interaction: No hard line data to answer that question per the FDA or the manufacturer. If you are worried about drug interactions then, it'd be best not to take one of these agents while on the other AT ALL. However, the interaction is considered minor if monitored carefully. So if you wanted to MAXIMALLY reduce interactions with one another you'd probably place them at least 6 hrs. apart. Your doc's thought?

Xanax (alprazolam): Not advised to take within at least 8 hours. The 3mg. dose is above therapeutic dose.