Drug Interactions of PDE5 inhibitors (Viagra, Levitra, Cialis)

The most common interactions associated with these medications are:

• nitrates- such as nitroglycerin by lowering blood pressure too much
• CYP3A4 inhibitors such as cimetidine, grapefruit juice, efavirenz, erythromycin, ketoconazole, itraconazole, retonavir, saquinavir, mibefradil Because impotence medications are broken down by a CYP3A4 enzyme, medications that make these enzyme less effective or less available can cause the side effects of Viagra, Levitra or Cialis to increase. If any the above medications are taken with impotence medications, lower doses of the impotence medications should be used and possibly reduced frequency, such as every two to three days.
• Medicines for high blood pressure, such as alfuzossin, doxazosin, prazosin, tamsulosin, or terazosin lower blood pressure. Care needs to be taken that blood pressure is not lowered too much by using lower doses of impotence medications

Online Medications

Men often desire treatment but frequently do not wish to go to their physicians to discuss impotence. Viagra, Levitra and Cialis are also relatively expensive and rarely covered by drug plans. As a result numerous websites have sprung up offering to sell these medications online at much lower prices and without a prescription. Counterfeit black-market medications often do not contain the ingredients they claim or the dosages they claim; this frequently puts the buyer?s health at risk.

Penile Suppositories and Injections

Alprostadil may be injected directly into the penis or administered by inserting a pellet form into the urethra to be absorbed into the corpus spongiosum. Alprostadil is effective in 50-80% of men, regardless of the cause of erectile dysfunction. This medication is sometimes chosen when oral medications have not produced the desired response or when a patient is unable to use these medications for other reasons. Alprostadil works even in the absence of mental sexual arousal. It works by directly stimulating the receptors that allow the smooth muscles in the blood vessels to relax; this allows increased blood flow to the penis to produce an erection. Alprostadil usually begins to work within 5 to 10 minutes and intercourse is generally recommended within 10 to 30 minutes. Alprostadil should not be used more than once in a 24 hour period, with injections limited to 3 times weekly or less.

Side effects of penile suppositories/injections

• Bleeding at the site of injection
• Pain at the site of injection
• Bruising or clotted blood in the area of the injection. This is usually caused by an incorrect injection.
• Penile scarring
• Painful erection

Contact your doctor if any of the following side effects occur

• Prolonged erection (lasting more than 4-6 hours, or if pain persists)
• Erectile curvature
• Swelling in or pain of the testes
• Dizziness
• Faintness
• Pelvic pain
• Flu-like symptoms