CVS Caremark Corp., the largest provider of prescription drugs in the U.S., is planning to raise cash in four parts to help fund its $2.1 billion takeover of specialty infusion services provider Coram LLC.

CVS may issue three-, five-, 10- and 30-year debt as soon as today, according to a person with knowledge of the offering. Proceeds will be used to pay back commercial paper and general corporate purposes, including the buyout, the person said, who asked not to be identified because terms aren’t set.

CVS, which also runs the second-largest U.S. drugstore chain, agreed to buy the provider from Blackstone Group LP’s Apria Healthcare Group Inc. on Nov. 27, the Woonsocket, Rhode Island-based company said in a statement. With the deal, CVS will enter the business of providing therapies such as antibiotics, nutrition and pain medicine to patients intravenously.

The company last tapped the bond market in November 2012, issuing $1.25 billion of 2.75 percent notes due Dec. 1, 2022, according to data compiled by Bloomberg. The securities traded on Nov. 29 at 93 cents on the dollar to yield 3.67 percent, according to Trace, the bond-price reporting system of the Financial Industry Regulatory Authority.

The deal would be the largest for CVS since buying Longs Drug Stores for about $2.8 billion in 2008, beating the largest drugstore chain Walgreen Co. in a bidding contest.