Erection happens as a result of sexual stimulation. Due to stimulation, nitric oxide is produced and released in the penis. It helps guanylate cyclase, an enzyme, in production of cyclic guanosine monophosphate (cGMP). cGMP is very important for erec tion because it is the main controlling agent for increase and decrease of blood vessels sizes that bring in and take out blood from their penis. But vessels come back to the normal size and election ends only when phosphodiesterase-5, another enzyme, destroys cGMP. Now, Cilias/Tadalafil can prevent enzyme from destroying cGMP, which results in longer duration of cGMP in the penis. When cGMP is available for longer duration, the erection is sure to stay for longer.
FDA approved Cilias/Tadalafil in November 2003. Most of the users of Cilias/Tadalafil can start it with a dose of 10 mg per day. Doctors recommend taking it just before any sexual activity. That dose is flexible and it can go up to 20 mg per day or go down to 5 mg a day. But dose depends on the response to the patient and any side effects. In general, it is effective up to 36 hours. There is a restriction on the dose for people who are taking other medications that can increase the level of Cilias/Tadalafil in the blood.
In such cases, that dose should not exceed 10 mg in 72 hours. Absorption of Cilias/Tadalafil is not affected by food and so you can take it at any time you like. Erythromycin, ketoconazole (Nizoral), itraconazole (Sporanox), indinavir (Crixivan) and ritonavir (Norvir) do not go well with Cilias/Tadalafil as they reduce its breakdown and elimination. As a result, you may suffer from side effects due to high level of Cilias/Tadalafil in the blood. This can be avoided using a reduce dose of Cilias/Tadalafil. Avoid using Cilias/Tadalafil with nitrates. Nitrates like nitroglycerin, isosorbide dinitrate (Isordil), isosorbide mononitrate (Imdur, Ismo, Monoket), nitroglycerin (Nitro-Dur, Transderm-Nitro) are used in treatment of angina for heart pain.
Nitrates generally increase heart rate and lower blood pressure and this effect can be exaggerated by combination of nitrate and Cilias/Tadalafil. It may also result in heart attack or heart pain.