Products that are regulated by Health Canada as a drug are not subject to the provisions of WHMIS pertaining to MSDS and labeling (see the excerpt below).  Products in this category will have appropriate labelling and package inserts.

...the provisions of this regulation in respect of a supplier label and a material safety data sheet do not apply where the controlled product is an ...drug or food within the meaning of the Food and Drug Act (Canada).   (section 2.(2)b.)

Excerpt from: Workplace Act: Workplace Hazardous Materials Information Service Regulation, B.C. Reg. 258/88

Application

2.(1) This regulation applies to employers and workers in respect of controlled products used, stored or handled at a place of employment.

(2) Notwithstanding subsection (1), the provisions of this regulation in respect of a supplier label and a material safety data sheet do not apply where the controlled product is an

1. explosive within the meaning of the Explosives Act (Canada),
2. cosmetic, device, drug or food within the meaning of the Food and Drug Act (Canada),
3. control product within the meaning of the Pest Control Products Act (Canada),
4. prescribed substance within the meaning of the Atomic Energy Control Act (Canada), or
5. product, material or substance packaged as a consumer product and in quantities normally used by the consuming public.

(3) Notwithstanding subsection (1), this regulation does not apply where the controlled product is

1. wood or a product made of wood,
2. tobacco or a product made of tobacco,
3. a manufactured article, or
4. being transported or handled pursuant to the requirements of the Transportation of Dangerous Goods Act (Canada) or the Transport of Dangerous Goods Act.

(4) Notwithstanding subsection (1), this regulation does not apply to a hazardous waste except that the employer shall ensure the safe storage and handling of a hazardous waste generated at that place of employment through the combination of any mode of identification and worker education.