Health stocks were mixed on relatively light news Monday, with one regulatory-inspired exception.

Big pharma stocks were both up and down -- but not by much -- pushing the Amex pharmaceutical index down about 0.59, or 0.2%, at 317.17. Component King Pharma ( kg) continued a second trading day of rebounding from its earnings damage last week. The stock added 36 cents, or 3.4%, to $11.07.

On the biotech side, the Amex and Nasdaq biotechnology indices gained 1.1% and 0.9%.

A component of the Nasdaq index, Cardiome Pharma ( CRME), was creamed after the company announced receipt of an "approvable" letter for the intravenous version of its Vernakalant, an experimental drug for irregular heart rhythm.

The company said it could take several months to respond to the letter, in which the FDA asked for safety data from ongoing and completed trials. Regulators could require an additional trial, although Cardiome said it is optimistic that won't be the case. The stock was falling $2.55, or 21.3%, to $9.40.

Elsewhere, Enzon Pharmaceuticals ( ENZN) said it is exploring strategic alternatives for its specialty pharmaceutical business. The company said it might sell the entire business or one or more of its products, and its manufacturing facility in Indiana.

Enzon said it has received confidential interest in all or parts of the specialty pharmaceutical business, and is evaluating the sale process. It previously announced it would spin off its biotech business. Shares were up 4 cents to $8.80.

In earnings, Obagi Medical ( OMPI) edged past Street expectations for its recent quarter but scaled back guidance. The company said it earned 20 cents a share on revenue of $27.8 million, while analysts polled by Thomson Reuters had expected 19 cents a share on $27.2 million.

Obagi also set new guidance that implies a full-year profit outlook of between 72 and 77 cents a share, vs. previous guidance of between 94 and 98 cents a share. However, Obagi shares were trading up 19 cents, or 2%, at $9.69.

Then, in analyst actions, Brean Murray downgraded Halozyme Therapeutics ( HALO) to hold from buy. The stock flirted with the flat line on Monday.

Also, on the small-cap side, CIBC downgraded Labopharm ( DDSS) to sector underperform from sector perform. That stock was off by 8 cents, or 6.4%, at $1.17 on light-but-average volume.