A lot of the discussion related to curbing runaway drug prices in the United States has focused on the importation of drugs from neighboring Canada. But are drugs really less expensive there? Often, the answer is yes. For instance, here are five common medicines that are much cheaper to buy in Canada than in the United States.

Image source: Getty Images.

No. 1: EpiPen

Mylan's (MYL) been on the hot seat since last summer's revelation of regular price increases on the life-saving EpiPen. The treatment for severe allergic reactions has become a staple in schools, businesses, glove boxes, and purses, but its price in the United States has marched steadily higher, until recently.

According to the Elsevier Gold Standard Drug Database, a pair of EpiPens cost $93.88 when Mylan acquired the drug back in 2007. Since then, EpiPen's price increased to $264.50 in 2013, $461 in 2015, and to about $600 last summer. As a result, EpiPen became a billion-dollar blockbuster medicine.

Fortunately, price scrutiny resulting from reports of EpiPen's historical price increases has forced Mylan to launch a cheaper formulation and boost discounts, and that's brought the price of a two-pack down to about what it also costs in Canada. However, prior to Mylan's changes, an EpiPen two-pack cost about one-third of what it cost in the United States, or about $225.

No. 2: Invokana

Johnson & Johnson's (JNJ -2.48%) Invokana is a relatively new, yet top-selling, diabetes medicine used to better control insulin levels. It works by inhibiting sodium glucose co-transporter 2, which reabsorbs glucose in the kidneys. By inhibiting the ability to reabsorb glucose, Invokana allows more glucose to exit the body through urine. Currently, Invokana generates over $1 billion in global sales for J&J, the vast majority of which come from sales in the United States.

According to GoodRx, a 30-tablet supply of Invokana at a 100 mg dose will set you back $411 at Walgreens in the U.S., with a coupon. Meanwhile, a month's supply of that same dose of Invokana in Canada costs about $234.

No. 3: Tecfidera

One of the biggest advances in multiple sclerosis treatment has been the launch of drugs that can be taken orally, rather than via infusion. While there are three top-selling oral MS drugs on the market, the best selling of them is Tecfidera, which is manufactured by Biogen (BIIB -3.17%)

Tecfidera is Biogen's best-selling medicine, and its sales totaled $2.97 billion through the first nine months of 2016. Of that revenue, $2.37 billion was from sales in the United States.

A search on GoodRx reveals that a 60-capsule package of 120 mg Tecfidera costs $6,805.76 at Wal-Mart, or $113 per capsule. Meanwhile, a search on Canada Drugs website reveals that a 42 capsule supply of 120 mg Tecfidera costs $1,177.80, or $28.04 per capsule.

No. 4: Advair

If you suffer from asthma or COPD, you might be prescribed the multibillion-dollar blockbuster Advair Diskus. Advair Diskus is manufactured by GlaxoSmithKline (GSK -1.38%), and with about $1.1 billion in quarterly sales, including $597 million in the U.S., Advair is Glaxo's best-selling product.

In the U.S., patients will pay $386.97 for 1 inhaler of Advair Diskus 250 mcg/50mcg, with a coupon, at Rite Aid, according to GoodRx. Get your prescription filled in Canada, however, and that same dose of Advair Diskus could cost you only $131.87.

No. 5: Januvia

Januvia is another pricey diabetes medicine in the United States that can be bought much cheaper in Canada. Unlike Invokana, Januvia works by inhibiting the activity of the DPP-4 protein to increase insulin production and decrease the production of sugars in the liver. It's often used in combination with metformin, the most widely used diabetes medicine, and Merck & Co. (MRK -0.01%), Januvia's manufacturer, reports Januvia's sales clocked in at $1.5 billion during the the third quarter of 2016. 

In the U.S., filling a one-month prescription for 100 mg of Januvia can cost about $382. However, in Canada, that same one-month supply can be had for $105.03.

Looking forward

It's not clear what changes will be made to lower the high cost of prescription medicine in the U.S., but pushback against sky-high drug prices suggests that Washington could take action, if drugmakers don't self-regulate on pricing. Among the ideas being considered to lower patients' cost is allowing the importation of drugs from lower-cost markets, such as Canada. Whether such a program ever makes its way through Congress is unknown, but it's clear, at least in these instances, that there could be substantial savings to consumers if importation laws pass.