Merck & Co’s earnings have fallen for the second quarter, though the asthma treatment Singulair and the diabetes drug Januvia have performed better than most analysts expected.

Net income came in at $1.56 billion, down 12%, hit by restructuring charges and merger-related expenses, while revenues fell 3% to $5.90 billion. However that would have constituted a rise of 3% were it not for the negative impact of currency.

The bright spot in terms of sales was the performance of Singulair (montelukast). Revenues from the drug have declined over the past year due in part to concerns about a potential link to suicidal behaviour, but second-quarter sales were up 16% to $1.3 billion.

Januvia (sitagliptin) generated $462 million for the quarter, up 38%, while Janumet (sitagliptin plus metformin) brought in $155 million, up 113% from the second quarter last year. Turnover from the recently-launched HIV drug Isentress (raltegravir) reached $172 million, up 123%.

On the negative side, sales of Vytorin (ezetimibe plus simvastatin) and Zetia (ezetimibe) fell 10% to $1 billion, while the cervical cancer jab Gardasil slumped 18% to $268 million. Revenues from the anti-hypertensives, Cozaar (losartan) and Hyzaar (losartan plus hydrochlorothiazide) were down 4% to $906 million, while sales of the osteoporosis drug Fosamax (alendronate) slumped 33% to $277 million, as the loss of patent protection in the USA takes a grip.

Chief executive Richard Clark said that the company “delivered solid operational results”, having made “significant investments to further strengthen our pipeline”. He also looked forward to the forthcoming merger with Schering-Plough, which should close in the fourth quarter and will expand its pipeline and portfolio, leaving Merck “well positioned as a global health care leader”.