HI Daffodil,
After initial MM diagnosis, I was started on VDT combination, 28 day cycles, and certainly was not fit for (office) work during this time. While I had no major side effects, I was simply too weak to entertain any form of office commute, and my mind would not cope with the usual daily work pressures.
Six cycles were planned, but five was enough to get me on the list for a SCT. And after the SCT it was another 3 months before I was fit for work.
But it all seems to vary greatly for each individual. As you will no doubt see as you browse through the forum and find others advising of how it affected them.