Avanafil (Stendra), tadalafil (Cialis), and vardenafil (Levitra) are other ED medications that are available in the United States. All of these increase blood flow to the penis. The drugs, when used in conjunction with sexual stimulation, have the potential to produce an erection strong enough to start and end sexual activity. Staxyn, a sublingual form of Levitra that dissolves quickly, is another option.