A nurse is teaching a patient about the use of sildenafil (Viagra) for erectile dysfunction. Which statement by the patient indicates understanding of the teaching?

This drug may cause me to have an erection one week after taking it.

I should take this drug 1 minute before sexual activity.

If my erection lasts longer than 6 hours, I should contact my provider.

If I have chest pain with sildenafil, I can use my nitroglycerin as prescribed.