I am 59 (weight 158) and was having big problems with flow and frequency. Started Flomax about 3 months ago. The flomax worked great but I noticed the side effects immediately (dizzy/light headed/trouble sleeping). After about 3 weeks I began taking it every other day which helped reduce the side effects but didn't hurt urine flow etc. Still the dizziness etc was too much sometimes so I opened the capsules and took 1/4 to 1/3 dose. This is working best for me. Almost no dizziness and urine flow is still good.
P.S. Watch out using flomax in 100 degree heat. The heat seemed to magnify the dizziness factor and ringing in the ears.