The US pharmaceuticals company Merck has announced a rise in its second-quarter profits of 5%, a slower rate of increase than in previous quarters.

But the results were in line with expectations following the profits warning Merck issued on 22 June.

Net income rose to $1.82bn from $1.72bn in the same quarter last year, and earnings per share came in at 78 cents.

Profits have been hit by disappointing sales of its Vioxx arthritis treatment and by the strength of the dollar, which has lowered the value of sales in countries with weaker currencies.

Not fast enough

Sales of Voixx reached $725m in the quarter. That's a 53% rise from the second quarter in 2000, but analysts had been hoping for faster growth this year.

Sales of Merck's biggest selling drug Zocor - a cholesterol treatment - were up 5% on the previous year to $1.36bn.

Analysts are concerned that sales of Merck's main five drugs are not rising fast enough to compensate for a number of patent expirations.

Merck's shares hit an all time high in November last year, but have since fallen back nearly 30%. The stock dropped nearly 9% when the company issued its profits warning last month.