There is speculation as to the effect of time travel when in space. Some people say that to mitigate the space shift, you need to drink beer.. Lots of beer.. and nuts. There isn’t much you can do for time travel disorientation though because if you are traveling forward in time, you took the medicine too long ago for it to have much effect.

Traveling ‘back in time’, didn’t make the medicine more effective (it wasn’t) but you didn’t suffer the side-effects until you resumed your normal time sphere. Of course, the farther back in time you traveled, the more seriously detrimental the side-effects would be if you were ever to get back to your normal time zone.

That is probably why the High Mouse didn’t tell Flandip and Tobin they were going back in time 4.5 billion years earlier than needed. They didn’t need to arrive to Earth that early, however, The High Mouse felt that adding the 4.5 billion years to the report was more impressive than writing .5 billion years. He had always hated decimals.