Europe is at a precipice, as voters across the continent have shown they are fed up with the existing political order and its prescription of austerity.

France's conservative government, led by Nicolas Sarkozy, was thrown out of power two weeks ago by Francois Hollande's left-leaning Socialist Party. Over the weekend, Angela Merkel's center-right Christian Democratic Union suffered its worst defeat in local elections since World War II. And Greece appears to be headed for a fresh general election, as its fractious political parties seem incapable of forming a coalition government.

For the first time, European leaders are even talking openly about a fissure in the continent's monetary union. Belgium's central-bank president told the Financial Times: "I guess an amicable divorce -- if that was ever needed -- would be possible, but I would still regret it." And his Irish counterpart echoed the sentiment: "Things can happen that are not imagined in the treaties … but [a Greek exit] can be managed. … It is not necessarily fatal, but it is not attractive."

For investors, the significance of such an eventuality cannot be overstated. If the monetary union fractures, an epidemic of currency devaluations will almost certainly ensue, causing American-made goods to increase in price on a relative basis, thereby driving down the continent's demand for them. In the pharmaceutical industry specifically, the following five companies will be among those feeling the biggest impact, as all of them look to Europe for a considerable portion of their sales.

Company

European Exposure (Percent of Net Sales)

Market Cap (Billions)

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Merck (NYSE: MRK) 29%* $116 Add
Johnson & Johnson (NYSE: JNJ) 26% $175 Add
Pfizer (NYSE: PFE) 24% $170 Add
Abbott Laboratories (NYSE: ABT) 22%** $97 Add
Bristol-Myers Squibb (NYSE: BMY) 17% $56 Add

Sources: All geographic sales figures other than Johnson & Johnson's are from the respective companies' most recently filed annual reports. Johnson & Johnson's are from the company's most recent quarterly report. Market cap data is from Yahoo! Finance.
*Merck's European division includes sales from the Middle East and Africa.
**Abbott Labs sales figures are from Germany, the Netherlands, Italy, France, Spain, and the United Kingdom.

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Fool contributor John Maxfield has no financial stake in any of the companies mentioned in this article. The Motley Fool owns shares of Johnson & Johnson and Abbott Laboratories. Motley Fool newsletter services have recommended buying shares of Johnson & Johnson and Pfizer and creating a diagonal call position in Johnson & Johnson. The Motley Fool has a disclosure policy. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. Try any of our Foolish newsletter services free for 30 days.