Used for treatment of CMV retinitis in HIV patients. Toxic effect on kidney function Topically used for intralesional treatment of recurrent laringeal papillomatosis caused by the Human Papilloma Virus, even in infants and children, without side effects. Serum level after intralesional injection varies from 0 to 0.4 mg/L, which is fifty times lower than after intravenous administration. Excretion into breast milk is unknown but absorption by the intestine should be very poor.