Ronny Gal, an analyst at Sanford C. Bernstein & Company, estimated in a note on Monday that Mylan’s overall revenue per epinephrine auto-injector prescription would be reduced by around 25 percent, to about $280, because of the introduction of the generic.

A couple of factors are expected to limit that revenue decline. The term EpiPen is so familiar that many doctors write prescriptions for it by name, rather than for a generic epinephrine auto-injector. While pharmacists in many states will be able to substitute the generic version, some are almost sure to sell the branded version instead, leaving Mylan with higher revenue.

In addition, Mr. Fein said, insurers might have negotiated deals with Mylan that make the brand-name version less expensive for them than the generic. “It’s going to depend on your particular insurance plan, and the kind of deal they have negotiated,” he said.

Consumers might also have incentives to use the brand-name drug in some cases because most of them would have no co-payments if they use a savings card being offered by Mylan. They might face a co-payment, albeit a relatively small one, for the generic product.

Despite the lower revenue from releasing the generic, Mr. Gal said the move could be good for Mylan shareholders by easing the downward pressure on the company’s stock. After falling more than 10 percent last week, Mylan shares were up slightly on Monday.



It is not uncommon for brand-name companies to introduce a generic version of their own product — known as an authorized generic, in part to try to retain some sales once generic competition arrives. But the generic industry and some other critics say the practice undermines the economics of the generic business and ultimately can lead to higher costs for consumers and insurers.

A study by the Federal Trade Commission several years ago found that some generic manufacturers agreed to delay the introduction of their generic product by years if the brand-name company promised not to introduce an authorized generic.