Apr 28, - Table 1. Benzodiazepine Equivalency Approximately Equivalent Oral Doses, mg Time to Peak Level, hours Half-life, hours Alprazolam (Xanax) 0. 15– Lorazepam (Ativan). 1–2. Nitrazepam (Mogadon)*. Furthermore, both drugs are high potency medications that are administered in doses of 1 mg or less. Ativan dosage: mg. Xanax dosage: mg. Comparative dosages alprazolam, diazepam, lorazepam, oxazepam, temazepam, Alprazolam (Xanax ®) The usual dose is 3 mg twice or three times daily.