For mild sore throat that leads to cough, I would chew on Ming's Pei Pa Koa Lozenges. It is not a drug, so for me, I guess there is no limit to taking it. It is very effective in relieving, even healing my sore throat that if I chew on one at the onset, the sore throat would not prosper to a full blown cough.
There are other brands, but I especially like Ming's Pei Pa Koa. It tastes rather sweet and minty for a throat lozenge, but it works wonders for me. Sometimes I would chew on it at night just before going to bed. And since I am sleepy, I would snooze with it in my mouth. And it is ok. It is also rather cheap at a dollar per 20-pc pack. But well, price does not really matterif a product works, right?
Just a warning though, I believe this is not for everybody. My husband and I trust pei pa koa, but my parents have experienced adverse reactions and so would not take it anymore. They find that their sore throats worsen with pei pa koa.
Pei pa koa is available in Chinese drugstores, coventional pharmacies, and even supermarkets. I am glad that even though it is alternative, it is not hard to find.