Medications that cause "vivid dreams"

[pkbites]

When I went to India I had to take anti-malaria medicine. The pharmacist warned me that one of the more common side effects were "vivid dreams".

Vivid dreams, indeed! That stuff gave me the craziest, whacked out dreams EVER.
I've had some real doozies in my life, but the dreams those pills gave me put anything Stephen King or Clive Barker ever wrote to shame. They were a real hoot.

I've noticed recently some meds being advertised that state the side effects also being vivid dream.

My questions are, what is in some medication that causes such dreams. And, would it be feasible to market a pill whose sole purpose was to cause such dreams?