It's better to adjust the toothed cog inside the drum than it is to tighten the cable at the handbrake.
Pull out the drum or the rotor (if you have rear disc) and there is a cog in the centre that you turn with a screwdriver or something and tighten it that way. I found my old drums used to loosen up after 2 weeks and I just got sick of adjusting them (hence the disc conversion). I got to 90,000km and the leading shoes still had 3mm of meat on them.