ANAHEIM, Calif. (AP) — Questcor Pharmaceuticals Inc. said Tuesday that its net income nearly doubled in the fourth quarter on an increase in prescriptions of its H.P. Acthar Gel, which is used to treat several autoimmune and inflammatory diseases.

Questcor said its sales increased because more physicians prescribed Acthar as a treatment for nephrotic syndrome, a kidney condition. The company also started selling the injectable gel as a treatment for rheumatology conditions. However it said prescriptions for multiple sclerosis decreased compared to the third quarter — although they improved compared to last year.

The company said it shipped 6,330 vials of Acthar gel during the fourth quarter, up 88 percent from a year ago.

Net income grew to $61.9 million, or $1.03 per share. A year ago it reported net income of $31.6 million, or 48 cents per share. Earnings were $1.09 per share, if one-time items are excluded. Revenue more than doubled to $160.5 million from $75.5 million.

Analysts expected net income of 93 cents per share and revenue of $142.2 million, according to FactSet.

Questcor reported net income of $197.7 million, or $3.14 per share, for all of 2012. It earned $79.6 million, or $1.21 per share, in 2011. Revenue climbed to $509.3 million from $218.2 million.

Shares of Questcor lost more than half their value in mid-September after health insurer Aetna Inc. said it planned to stop covering all uses of Acthar except infantile spasms. It said there is not enough clinical evidence that Acthar is more effective than steroids in treating other conditions. Aetna's announcement caused Wall Street to worry that other insurers will also reduce their coverage of Acthar and diminish Questcor's revenue.

However the stock has since recovered most of its losses, up 83 percent since Sept. 27.

Questcor shares fell $1.98, or 6.1 percent, to $30.68 in after-hours trading. The stock rose 5.2 percent to close at $32.66 in the regular session.