Healthcare giant Johnson & Johnson posted a mixed set off results yesterday, with a 16% rise in net income, helped by a one-off payment related to its failed merger with Guidant.

But group revenues were up only slightly as a good performance by its medical devices division struggled to offset the effects of generic competition to some of its prescription drugs.

Net income came in at $3.3 billion, with a $705 million contribution paid by Guidant after the two companies’ proposed merger was broken up by rival suitor Boston Scientific. Group sales were up just over 1% to $12.99 billion, a little shy of a poll of analysts by Thomson First Call which predicted sales of $13.22 billion.

Sales at J&J’s core pharmaceuticals division were down 2.2% compared to the first quarter of 2005, at $5.6 billion, as a result of generic competition to its painkillers Duragesic (fentanyl) and Ultracet (tramadol) and the antifungal Sporanox (itraconazole).

On the plus side, schizophrenia drug Risperdal (risperidone), epilepsy treatment Topamax (topiramate), Concerta (methylphenidate) for attention deficit hyperactivity disorder and Remicade (infliximab) for rheumatoid arthritis and other immune disorders helped offset the decline.

Risperdal sales climbed 21% to $1.01 billion, Topamax rose 16% to $471 million and Concerta came in at $235 million, up 19%. Remicade, which is sold by Schering-Plough in most countries outside the USA, rose 18% compared to a year ago to reach $681 million.

Meantime, US sales of J&J’s Cypher (sirolimus) drug-eluting stent, used to hold open diseased coronary arteries, rose 15% to $366 million and giving it a 47% share of the market, up eight points from a year ago.

This product’s performance contrasts with that of arch-rival Taxus (paclitaxel) from Boston Scientific, which fell 8% in the first quarter, although Boston Scientific claimed in its own results statement that it is no longer losing market share to Cypher.