Oral Medications for Erectile Dysfunction
How and When to Take the Medications
- Take 50 mg of Viagra one hour before you are ready to engage in sexual activity.
- Viagra works best 30 minutes to four hours after taking the pill.
- Viagra also works best on an empty stomach. Do not take the pill after a high-fat meal.
- If you do not achieve an erection with sexual stimulation, you can increase the dosage of your medication the next time sexual activity is planned. After surgery, most men require doses of 100 mg, or more, of Viagra.
- Within eight to 12 hours, Viagra is almost completely eliminated from the body.
- Take 10 mg of Levitra 30 minutes to one hour before you are ready to engage in sexual activity.
- Levitra works best 30 minutes to four hours after taking the pill.
- If you do not achieve an erection, you may need to increase the dosage. Consult your doctor.
- Levitra cannot be used with some medications. These include Flowmax, Hytrin and Cardura.
- Take 10 mg of Cialis at least two hours before you are ready to engage in sexual activity.
- Cialis can be taken on a full stomach following meals and the effect of medication may last up to 36 hours.
- If you do not achieve an erection on 10 mg, higher dosages can be taken, though you must consult your doctor regarding higher doses.
- Cialis cannot be used with some other medications. These include Hytrin and Cardura. Flomax in doses of 0.4 mg is well tolerated.
- The most common side effects of oral medications for erectile dysfunction include headache, facial flushing and upset stomach.
- A small number of patients taking Viagra or Levitra may complain of a "blue cast" to their vision, sensitivity to light or blurred vision.
- Cialis does not cause visual side effects. However, back pain and joint aches can occur with Cialis.
Important Things to Remember
- Although Viagra, Levitra and Cialis have been shown to be effective in many men with erectile dysfunction, they are not effective in patients who have a prostatectomy, unless a nerve-sparing approach was used.
- These medications must not be used with medications containing nitrate, such as nitroglycerin, Nitrostat, Nitro-Bid, Nitro-Dur, Isordil and Ismo, or Deponit.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.
Drugs Reported to Cause Priapism
In one-third of the cases, the cause of priapism is unknown. A variety of medications or recreational drugs also can lead to priapism. Find a list here.
Erectile Dysfunction Causes
The greatest medical risk factors for erectile dysfunction include diabetes mellitus, heart disease, and hypertension. Learn more here.
Patient Guide to Penile Injections
Although you probably find the idea of injecting something into your penis unappealing, many men are highly satisfied with this therapy. Learn why here.