Bosentan an non selective endothelin antagonist is an approved drug for pulmonary arterial hypertension.
Even this drug has not fully proven it’s worth . Meanwhile , a relatively unknown company manufactured sitaxentan a similar molecule with a self claimed selective endothelin blocking property .
Pfizer bought this company and marketed it as Thelien . The liver injury is less than bosentan , they claimed and it was prescribed once a day .The same old story unfolds.physiological endothelin in liver was in appropriately blocked and caused dangerous forms of liver injury.
Only one difference this time , Pfizer self banned this drug and stopped all research activities about this molecule.
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Dr.S.Venkatesan MD 