Pfizer's blockbuster drug Viagra (sildenafil citrate), hitherto approved for use in treatment of erectile dysfunction, may soon acquire a new identity as a "life saving drug" in treating pulmonary arterial hypertension in children.

While the ongoing global clinical trials conducted by Pfizer on the new use of the drug is showing promising results, Indian drug regulators are exploring the possibilities of making the drug legally available for additional indications.

Doctors in various Indian hospitals are already prescribing sildenafil in critical cases.

Though the drug is not meant for other indications, the off-label use of sildenafil, using doctors' discretionary powers, is proving to be "live saving", a National Pharmacovigilance Advisory Committee source informed.

The NPAC, which had put sildenafil citrate under the "focused monitoring" list of drugs, is known to have seen no adverse reactions that suggest further restrictions on the drug.

Further, according to research around the world, sildenafil can work wonders in some life-threatening situations.

Viagra are currently approved as a prescription drug for use in erectile dysfunction and enjoy a domestic market worth Rs 100 crore (Rs 1 billion).