Pfizer has reported a major rise in sales for the first quarter, thanks to the contribution of Wyeth, but like at Merck & Co, charges from that acquisition pushed the drug giant’s earnings down.

Net profit fell 26% to $2.03 billion, while turnover came in at $16.75 billion, an increase of 54%, and 48% of that rise was due to Wyeth products. Sales of Pfizer’s own drugs actually slipped 1%.

Biopharmaceutical sales leapt 44% to $14.51 billion and revenues from the cholesterol blockbuster Lipitor (atorvastatin) edged up 1% to $2.76 billion, though US sales fell 10% to $1.31 billion, hit by competition from other statins, notably the generic version of Merck & Co’s Zocor (simvastatin). Generic competition also hurt the blood pressure treatment Norvasc (amlodipine), which fell 23% to $368 million.

On the positive side, sales of Lyrica (pregabalin), for epilepsy, fibromyalgia and neuropathic pain, increased 6% to $723 million, while the kidney cancer treatment Sutent (sunitinib) jumped 28%% to $259 million. The COX-2 inhibitor Celebrex (celecoxib) inched up 1% to $570 million and the erectile dysfunction drug Viagra (sildenafil) brought in $479 million, up 5%, while the glaucoma drug Xalatan (latanoprost) had sales of $422 million (+4%). The smoking cessation drug Chantix/Champix (varenicline) rose 7% to $189 million.

The figures were boosted by a number of Wyeth products, notably the antidepressant Effexor (venlafaxine), which contributed $716 million, the pneumococcal disease vaccine Prevnar ($286 million) and the arthritis and psoriasis therapy Enbrel (etanercept; $802 million outside North America). Wyeth’s antibiotic Zosyn/Tazocin (piperacillin/tazobactam) brought in $264 million, while the Premarin (conjugated oestrogens) range of hormone replacement therapies contributed $256 million to Pfizer’s coffers.

Pfizer’s new ‘diversified’ division, which includes animal and consumer health products, plus nutritional items and capsules for drugs made by Wyeth, saw revenues climb 210% to $2.14 billion. US healthcare reforms reduced first-quarter revenues by $56 million.

The latter effect will impact sales by about $300 million this year, said chief financial officer Frank D’Amelio, but he noted that the company is sticking by its earnings forecast of $2.10-$2.20 per share, with revenues expected to be $67-$69 billion. However, for 2012, Pfizer is targeting turnover of $65.2-$67.7 billion, down $800 million on a previous guidance.