The number of deaths suspected to be linked to adverse side-effects of the blood thinner heparin has climbed from 19 to 62, according to the U.S. Food and Drug Administration.

The FDA said Tuesday a review of adverse effects has shown that of the 103 patients who died while using the medication since January 2007, 62 deaths involved allergic reactions or hypotension. The FDA figures referred to heparin made by various manufacturers, including Baxter International.

In February, the FDA warned consumers that lots of heparin produced by Baxter were linked with side-effects including dizziness, difficulty breathing and nausea. Lots of heparin have since been recalled in countries including the U.S., Canada, Germany, France and Japan.

An FDA probe later found Baxter's heparin was tainted with a contaminant known as oversulphated condroitin sulphate.

Drug regulators in China say they have since stepped up checks in the manufacturing of heparin, which is produced from pigs' intestines.

Baxter says it has identified four deaths that may have been linked to recalled lots of heparin.

With files from the Associated Press