Common use
Cialis is an effective, reversible, selective inhibitor of phosphodiesterase type 5 (PDE 5) specific to cyclic guanosine monophosphate (cGMP). When sexual stimulation causes local release of nitric oxide, inhibition of PDE 5 by Cialis leads to increase of cGMP levels in the cavernous body of penis. It results in relaxation of arterial smooth muscles and blood flow to the tissues of the penis that causes erections. Cialis has no effect when sexual stimulation is absent. Cialis improves erection and lets achieve a successful sexual intercourse. The drug acts during 36 hours. If sexual arousal is present the effect appears even after 16 minutes after the medication was taken.

Dosage and direction
The recommended dose of Cialis is 20 mg it should be taken at least 16 minutes before the sexual activity. The effect persists during 36 hours. Take Cialis once daily and do not exceed the recommended dose.

Precautions
It is preferable not to use Cialis with grapefruit juice, alcoholic beverages, tobacco. If you smoke tobacco and take Cialis concomitantly this may lead to a condition called NAION (sudden optic nerve-related vision loss). Inform your doctor before to take Cialis if you have abnormal penis, including curved penis and birth defects of the penis, had coronary artery disease, arrhythmia, angina, heart attack or heart failure, hypo- or hypertension, bleeding, stomach ulcers, diabetes, hyperlipidemia (excess of lipids in the blood), sickle-cell anemia, liver or kidney failure in history.

Contraindications
Cialis is contraindicated in patients who are using any form of organic nitrate, either regularly and/ or intermittently as it is able to potentiate hypotensive effect of nitrates.

Possible side effects
Most usual side effects of Cialis are facial flushing (reddening), headaches, stomach upset, diarrhea, flu-like symptoms and nausea. In more rare cases low blood pressure, blurred vision and changes in color vision, and abnormal ejaculation may occur. Prolonged erections or priapism (painful erections lasting more than 6 hours) are also possible. If your erection is longer than 4 hours, seek for immediate medical help as it may permanently damage your penis. Aggravation of heart problems in patients with pre-existing heart disease using Cialis was reported.

Drug interactions
Co-administration with medications containing organic nitrates may cause severe hypotension which is dangerous in some cases. Avoid taking Calis with medications such as Erythrityl Tetranitrate, Isosorbide Dinitrate, Isosorbide Mononitrate, Nitroglycerin, Pentaerythritol Tetranitrate. Levels and toxicity of Cialis are increased by erythromycin, ketoconazole (Nizoral), itraconazole (Sporanox), indinavir (Crixivan) and ritonavir (Norvir). Inform your doctor if you are taking Atazanavir, Bunazosin, Clarithromycin, Doxazosin, Erythromycin, Indinavir, Itraconazole, Ketoconazole, Moxisylyte, Nefazodone, Nelfinavir, Phenoxybenzamine, Phentolamine, Prazosin, Saquinavir, Telithromycin, Terazosin, Trimazosin, Urapidil as your Cialis dose may require correction.

Missed dose
Missed dose is not supposed if Cialis is taken for treatment of erectile dysfunction as it s used when needed.

Overdose
Overdose of Cialis causes symptoms described as side effects. Seek for immediate medical help if you by your opinion you took too much of this medication.

Storage
Store at room temperature away from moisture, sunlight, kids and pets in a tight container.

Disclaimer
We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.