- Alternative therapies such as vitamins, acupuncture, and visualization techniques will be permitted. Herbal medications should be avoided. Patients should report the use of these therapies; alternative therapies will be recorded. [AS PER AMENDMENT 8/7/98: Due to the likelihood of IDV increasing the concentrations of sildenafil (Viagra) when coadministered, it is suggested that subjects who use viagra take the lowest dose (25 mg, i.e., half the typical dose).]