Recently, my friend developed a chronic illness. He faced an unaffordable cost for a medication available through his Medicare Part D drug plan. Then he discovered international shopping.

His doctor diagnosed him with an irregular heart beat called "atrial fibrillation," which increases his risk of forming a blood clot in his heart that could float to his brain causing a stroke. To mitigate this risk, his doctor prescribed an anticoagulant, commonly known as a "blood thinner."

The doctor wrote a prescription for Eliquis—which is a brand name for apixaban: to be taken twice a day for the rest of his life.

The doctor suggested an alternative legacy "blood thinner," Coumadin—a brand of warfarin, which also reduces clots, but is dangerous if not carefully used. Warfarin first came into commercial use in 1948 as a rat poison. In 1954, it was approved for medical use in the United States. The World Health Organization lists it as an essential medicine, but it is dangerous—take too much and one can bleed to death.

Available beginning 2012, the benefit of apixaban is not inferior to warfarin, but can be safer and less hassle to use. Unlike apixaban, warfarin requires a blood test at least once a month to verify the correct dose.

A change in diet and concomitant use of other medication can alter the effect of warfarin requiring a dose adjustment. My friend chose to take apixaban.

Under the Medicare Part D prescription drug plan, a 2-week supply, 28 doses of apixaban costs $308. The out-of-pocket cost to my friend $216.16, $15.44 per day: $432 a month. Medicare D pays its share: $196.80 per month

He shopped around and found a pharmacy in a G-7 (highly developed) country that sells a 12-week supply, 168 doses of apixaban for $171: $2.04 per day: $61.20 per month -- an amazing 87 per cent savings!

For my friend, $61.20 per month is much more affordable than $432/month. He receives apixaban by mail every two months.

If he lives ten more years, his willingness to shop internationally will save him $44,461. By not using his Part D plan, Medicare will save $23,616 over 10 years.

So, if you are in the market for medications, shop internationally.

~ Dr. Jerry Rogan