24 January 2012 Last updated at 07:14 ET

Police investigate Pakistan heart drug deaths

The Pakistani pharmaceuticals market is intensely competitive

At least 36 people with cardiovascular problems have died in a Lahore hospital over the past three weeks because of faulty drugs, Pakistani officials say.

Police have arrested the owners of two local pharmaceutical firms that supplied the drugs to the government-owned Punjab Institute of Cardiology.

Neither of the two firms have commented on the allegations.

Doctors believe one or more of at least four drugs given to patients at the institute directly led to their deaths.

The drugs were purchased at competitive rates and were allegedly offered to patients free of cost.

"More than 100 patients brought to various hospitals in Lahore for suspected drug reactions have all been recently under treatment at Punjab Institute of Cardiology, and were given these drugs," Punjab provincial Health Secretary Jehanzeb Khan said on Monday.

Dr Javed Ikram of the Allama Iqbal Medical College - one of the biggest medical colleges in the country - told the BBC that the drug reaction was initially marked by rapid depletion of bone marrow, white cells and platelets - causing bleeding and death.

The BBC's M Ilyas Khan in Islamabad says the Pakistani pharmaceuticals market is intensely competitive, with local companies competing with multinationals for hospital contracts.

This is thought to be the first time that drugs provided by Pakistani companies are alleged to have been below standard, our correspondent says adds.

Officials say they have sealed off one pharmaceutical firm and are sending the four drugs for testing abroad to determine which one of them caused the reaction, and why.

In a statement the Pakistan Medical Association urged the government to buy life-saving drugs from other suppliers.

Hospital sources told BBC if they do not buy drugs from the lowest bidder, they can be taken to court by local pharmaceutical companies and even be issued with an injunction against all future purchases.