Sales of Gilead Sciences' (Nasdaq: GILD) antiviral drugs have slowed considerably from their heyday a few years ago; the HIV and hepatitis B drugs grew by just 9% in the third quarter. Hypergrowth can't last forever.

Fortunately, Gilead looks like it might have a few tricks still up its sleeve that could boost sales. Or at least stabilize the decelerating growth.

The biotech launched its newest HIV treatment, Complera, this month, and the drug is off to a solid start, with $19 million in sales in the first seven weeks or so on the market. The drug, which combines Gilead's Truvada with Johnson & Johnson's (NYSE: JNJ) Edurant, provides Gilead better economics than its top-selling Atripla, which Gilead has to share with Bristol-Myers Squibb (NYSE: BMY).

Gilead also has a Quad regimen that's passed a pair of phase 3 trials. Yesterday the company said it had submitted the Quad for Food and Drug Administration approval, so Gilead could have another revenue-boosting drug on the market as early as April of next year.

Part of the Quad pill is a boosting agent called cobicistat, which Gilead is licensing out separately to earn a little extra cash on the side. Earlier this week, Gilead signed up Bristol-Myers to combine its already-approved Reyataz with cobicistat. The deal follows a similar one with Johnson & Johnson back in June. Cobicistat will compete directly with Abbott Labs' (NYSE: ABT) boosting agent Norvir, but the pair of deals seem to endorse cobicistat as the likely long-term winner.

And then there are Gilead's heart drugs, which are growing much faster than the antiviral segment. In the third quarter, Letairis and Ranexa were both up more than 30% year over year. At this point, neither drug is a blockbuster, and combined they only make up about 8% of sales, which makes it hard to move the revenue needle. If they keep growing at this pace though, they'll have a significant impact soon enough.

Gilead's never going to get to the 30% year-over-year growth that was typical a few years ago; that kind of growth would require the addition of over $2 billion in sales annually. But I wouldn't write off the company as a growth story just yet either.

Keep track of Gilead's launch of Complera and the FDA decision on the Quad pill by adding Gilead to the Fool's free My Watchlist service.