Cialis vs. Viagra

Cialis and Viagra are oral drugs used to treat impotence and benign prostatic hyperplasia (BPH). They belong to a class of drugs called phosphodiesterase-5 (PDE5) inhibitors, which also includes vardenafil (Levitra, Staxyn ODT), and avanafil (Stendra).

Penile erection occurs when the penis is engorged with blood. Sexual stimulation leads to the production and release of nitric oxide, which activates the enzyme guanylate cyclase. This enzyme causes the production of cyclic guanosine monophosphate (cGMP), which affects the amount of blood delivered and removed from the penis. Cialis and Viagra inhibit an enzyme called phosphodiesterase-5 (PDE5), which destroys cGMP. By preventing the destruction of cGMP, Cialis and Viagra allow it to accumulate, resulting in a prolonged erection.

Side effects of Cialis and Viagra

Cialis

WARNING: If you experience nausea, chest pain, or dizziness during sex while taking Cialis, seek immediate medical help as it may indicate a life-threatening condition.

The most common side effects of tadalafil (Cialis) include facial flushing, headaches, stomach upset, diarrhea, flu-like symptoms, and nausea. Other possible side effects include low blood pressure, blurred vision, changes in color vision, abnormal ejaculation, and priapism (an erection lasting more than four hours that can damage the penis).

Viagra

WARNING: If you experience nausea, chest pain, or dizziness during sex while taking Viagra, seek immediate medical help as it may indicate a life-threatening condition.

About 15% of people taking Viagra experience side effects. The most common ones are facial flushing, headaches, stomach pain, nasal congestion, nausea, dizziness, rash, urinary tract infections, diarrhea, and an inability to differentiate between green and blue colors. Priapism (an erection lasting more than four hours that can damage the penis) is also possible.

Dosage of Cialis vs. Viagra

Cialis

For most individuals, the recommended starting dose of tadalafil (Cialis) is 10 mg per day taken before sexual activity. The dose may be increased to 20 mg or decreased to 5 mg depending on the response and side effects. The effects of tadalafil can last up to 36 hours. The recommended dose for BPH or BPH with erectile dysfunction is 5 mg daily. The dose may need adjustment for patients with reduced kidney or liver function.

Viagra

• The usual recommended dose of sildenafil (Viagra) is 25 to 100 mg taken one hour before sexual activity.
• The maximum dose is 100 mg daily.
• Elderly individuals should start with 25 mg.
• When taken with a high-fat meal, absorption is delayed by one hour.

Drug interactions with Cialis and Viagra

Cialis

The breakdown and elimination of tadalafil (Cialis) can be affected by certain drugs, such as erythromycin, ketoconazole, itraconazole, indinavir, and ritonavir. These drugs may increase tadalafil levels in the blood. Rifampin, carbamazepine, phenytoin, phenobarbital may decrease blood levels of tadalafil, reducing its effectiveness. Tadalafil should not be combined with nitrates or alpha-blocking drugs for high blood pressure or BPH. Combining tadalafil with alcohol may cause a drop in blood pressure. Tadalafil should not be used in patients with bleeding disorders or active ulcers and should not be combined with Adcirca or other PDE5 inhibitors.

Viagra

Viagra can increase the effects of blood pressure-lowering medications and nitrates, which are used for angina. It should not be combined with other PDE5 inhibitors. Cimetidine, erythromycin, ketoconazole, itraconazole, atazanavir, and mibefradil may increase the amount of Viagra in the body. Rifampin may decrease blood levels of Viagra.

Safety of Cialis and Viagra during pregnancy and breastfeeding

Cialis

Tadalafil is not approved for women and has not been evaluated in breastfeeding women.

Viagra

Viagra has not been studied in pregnant women, but extensive testing in animals has shown no negative effects on the fetus. There is also no effect on sperm count or motility in men. Its excretion into breast milk is unknown.

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Summary

Cialis and Viagra are oral drugs used to treat impotence and BPH. They belong to a class of drugs called PDE5 inhibitors, along with vardenafil and avanafil.