Does a contacts prescription need to be changed to switch brands?

I'm in AcuVue Advance -6.00 in both eyes. 8.7BC and 14.0 DIA.

I'm looking at other more comfortable brands like Air Optix, for instance. They have a lower water content which will keep my eyes from drying out as much due to the environment that I work in.

Would I have to get my eye doctor to change the brand name on the prescription I order to buy some online? I just had an exam about 2 months ago, but was just starting my new job and didn't know what effect it would have on my contacts.
Added (1). I don't think they carry the brand that I am looking for in their office. Any advice on that without getting a new one?

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