Spedra is a treatment for erectile dysfunction that contains the active ingredient avanafil. Compared to other options, it works more quickly, with many men noticing results within just 15 minutes. Like all medicines, ED treatments can cause side effects. The most common include headaches, muscle aches, back pain, flushing, low blood pressure, vision changes, and indigestion. If any of these persist, consult your GP or pharmacist for advice.