You can find something called "Sterisol" containing Chlorhexedrine in the bottom shelves of Shopper`s Drugmart or Walgreens (no, I don`t work for them). Mind you, it really only works in combination with flossing. The same red fluid is called "Hexoral" in some European countries.
Peroxide, baking soda, tetracycline. But need to consult your dentist before.

But use of any medication alone will likely be insufficient to effectively treat periodontal (gum) disease.
Effective treatment of periodontal disease is a 3-step process:

1. Correct evaluation and diagnosis by a dental professional, along with initial therapy which may include deep scaling of the root surfaces of the teeth to remove accretions, placement of local antimicrobial therapeutics, prescribing oral medications such as antibiotics or anti-collagenase meds (Periostat), and possibly surgery.
2. Effective and frequent oral hygiene procedures (brushing, flossing, rinsing, etc.)
3. Regular and frequent monitoring and maintenance procedures by your dental professional.

There is no cure for gum disease. However, if diagnosed early, it can be effectively treated and controlled. Talk to your dental professional about the best options for you.