On the market is Caverta 100mg. This prescription drug treats erectile dysfunction. It increases blood flow to the penis. It helps men to maintain or achieve an erection. It belongs to the class of drugs called phosphodiesterase 5(PDE 5). Caverta 100 can be taken with or without food. Please follow the instructions of your doctor. Take your medication about an hour before sexual relations. It depends on the individual how long it takes to work. Between 30 minutes and an hour.