Coadministration has not been studied. Terazosin is extensively metabolized in the liver possibly via CYP3A4 and concentrations may increase due to inhibition of CYP3A4. For patients already taking nelfinavir, start terazosin at the lowest dose (e.g. 1 mg daily) and increase dose slowly based on tolerance until an effective dose is reached. For patients already taking terazosin, monitor blood pressure and reduce terazosin dose as needed if hypotension occurs on starting nelfinavir.