Viagra and Cialis: A Comparison of Two Well-Known Drugs
Gui í a de Salud Masculina
- I. the mechanism of drug action
- II. Matters needing attention in drug use
- Third, adverse drug reactions
Viagra (Viagra, sildenafil) and Cialis (tadalafil) are used to treat erectile dysfunction (ED) in men.
I. the mechanism of drug action
1 、Identical point
Both of them belong to phosphodiesterase 5 (PDE5) inhibitors. PDE5 is abundant in corpus cavernosum smooth muscle cells and can degrade cyclic guanosine monophosphate (cGMP). Under normal circumstances, sexual stimulation causes the release of nitric oxide (NO) in the corpus cavernosum of the penis. NO activates guanosine cyclase and promotes the conversion of guanosine triphosphate (GTP) into cGMP,cGMP. The smooth muscle of the corpus cavernosum is relaxed and blood flows into the cavernous sinus of the penis. As a result, penile erection can be made, and PDE5 inhibitors can increase the concentration of cGMP and enhance penile erectile function by inhibiting the degradation of cGMP by PDE5.
2 、Differences
Action time
Viagra (sildenafil)Sildenafil lasts for a relatively short time and lasts about 4-6 hours. Sildenafil is usually taken as needed about an hour before sexual activity.
Cialis (Tadalafe)Tadalafil is known as a "long-acting" ED drug for a long time, and its effect lasts about 36 hours, which means that patients are likely to have a normal erection whenever they are sexually stimulated within 36 hours after taking the drug, which is relatively more flexible and reduces the sense of urgency in time.
II. Matters needing attention in drug use
1 、intended for
These two drugs are mainly suitable for adult male patients with erectile dysfunction, but both need to be used under the guidance of a doctor.
2 、Contraindication
Common contraindication
-patients who are taking any form of nitrates (such as nitroglycerin, isosorbide mononitrate, etc.) are prohibited because a combination of the two can lead to severe hypotension.
-it is prohibited for those who are allergic to drug ingredients.
Special contraindication
Viagra (sildenafil)Patients with cardiovascular disease should be cautious when using sildenafil, as sildenafil may have a certain effect on blood pressure, and patients with severe hypotension, recent myocardial infarction and unstable angina pectoris are at higher risk.
Cialis (Tadalafe)Tadalafil also needs to be used cautiously in patients with cardiovascular disease, and the use of tadalafil may need to be adjusted or avoided in some special groups, such as patients with severe liver insufficiency.
Third, adverse drug reactions
1 、Common adverse reactions
Viagra (sildenafil)
Headache is a common adverse reaction, the incidence may be about 10%-20%, there may also be facial flushing, nasal congestion, indigestion and other symptoms, most of these adverse reactions are mild to moderate, usually gradually alleviated or disappeared after drug metabolism.
Cialis (Tadalafe)
Tadalafil may also cause headaches, indigestion, back pain and other adverse reactions, the incidence of back pain may be more special than tadalafil, in a certain proportion of patients will occur, but the overall adverse reactions are mostly mild to moderate.
Both drugs should be used under formal medical guidance and should not be used on their own at will to ensure the safety and effectiveness of drug use.