[1] The Federal Investigation Agency carried out an inquiry into the incident, and identified the factory of Efroze Chemicals in Karachi as the producer of the Isotab tablets contaminated with pyrimethamine.
In mid-January 2012, several cardiac patients registered with the Punjab Institute of Cardiology (PIC) started showing up at different public and private hospitals in Lahore after having a sudden drop in platelets and white blood cells and bleeding from different parts of the body.
[2] Suspect drugs included Isotab (isosorbide mononitrate), Lipitor (atorvastatin calcium), Cardiovestin (simvastatin), Alfagril (clopidogrel), Concort (amlodipine), and Soloprin (aspirin).
[7] As the death toll exceeded one hundred, the Lahore High Court ordered respondents involved in the case to file their replies by the 30 January 2012.
[8] Tests performed by the British Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom indicated that one of the five suspected drugs - Isotab - was contaminated.
[9] Tests done at the Central Drugs Laboratory in Karachi also verified the presence of pyrimethamine used in certain combinations to treat malaria in a sample of the Isotab tablet (20 mg).
[12] Moreover, the World Health Organisation issued a global drug safety alert (no.125) calling for increased vigilance on the use of Isotab manufactured by Efroze Chemicals.