Groggy! Does anyone take large doses of klonopin (clonazepam) or lorazapam?

Expect no different. If you take high doses (or even low doses) of either medication, it would not be uncommon for you to feel groggy. Both are benzodiazepines and are central nerve system depressants. They are designed to slow down your system and relax you. By so doing, however, they can make you tired, lethargic or sleepy. The higher the dose, the more sedating it becomes. Too high of dose can result in death.