From the Guidelines
Cialis (tadalafil) and Viagra (sildenafil) are both effective treatments for erectile dysfunction, but the most significant difference between them is their duration of action, with Cialis lasting up to 36 hours and Viagra lasting 4-6 hours, as reported in the 2018 erectile dysfunction guideline by the American Urological Association 1. The main differences between these two medications can be broken down into several key points:
- Duration of action: Cialis has a longer duration of action, making it a better option for patients who want to have spontaneous sexual activity without planning ahead.
- Onset of action: Both medications typically start working within 30-60 minutes, but Cialis can be taken with or without food, while high-fat meals can delay and reduce Viagra's effectiveness.
- Dosage: Cialis is available in daily low doses (2.5mg or 5mg) for ongoing treatment or higher doses (10mg or 20mg) for as-needed use, whereas Viagra is typically taken as needed in doses of 25mg, 50mg, or 100mg.
- Side effects: Both medications have slightly different side effect profiles, with Cialis causing back pain and muscle aches more commonly, and Viagra causing vision changes more frequently.
- Mechanism of action: Both medications work by inhibiting the enzyme PDE5, increasing blood flow to the penis during sexual stimulation. It's essential to note that the choice between these medications depends on personal preference, lifestyle, side effect tolerance, and other health conditions, as stated in the guideline 1. Additionally, patients should be informed about the benefits and risks of these medications, and the dose should be titrated to provide optimal efficacy, as recommended by the guideline 1.
From the FDA Drug Label
Tadalafil, USP is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Sildenafil tablets, phosphodiesterase-5 (PDE-5) inhibitor, is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type-5 (PDE-5).
The main differences between Tadalafil (Cialis) and Sildenafil (Niagara) are:
- Molecular formula and weight: Tadalafil has a molecular formula of C22H19N3O4 and a molecular weight of 389.41, while Sildenafil has a molecular formula of 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo [4,3-d] pyrimidin-5-yl)-4- ethoxyphenyl] sulfonyl]-4-methylpiperazine citrate and a molecular weight of 666.7.
- Indications: Although both are PDE-5 inhibitors, the provided drug labels do not directly compare their indications.
- Dosage and administration: The dosage and administration of Tadalafil and Sildenafil are not directly compared in the provided drug labels.
From the Research
Main Differences Between Tadalafil and Sildenafil
- Tadalafil and Sildenafil are both phosphodiesterase type 5 (PDE5) inhibitors used to treat erectile dysfunction (ED) 4, 5, 6, 7.
- Tadalafil is also used to treat the signs and symptoms of benign prostatic hyperplasia (BPH) 5, 6, 7.
- The mechanism of action for Tadalafil in treating BPH is thought to be related to alterations in nitric oxide levels, Rho-associated protein kinase deactivation, and reductions in pelvic atherosclerosis 7.
- Tadalafil has a longer half-life compared to Sildenafil, which may make it more effective for some patients 7.
- Tadalafil has been shown to improve ejaculatory function, erectile function, and sexual satisfaction in men with lower urinary tract symptoms suggestive of BPH and ED 8.
- Common adverse events associated with Tadalafil include back pain, dyspepsia, headache, and dizziness 7.
Comparison of Tadalafil and Sildenafil
- Both Tadalafil and Sildenafil are effective in treating ED, but Tadalafil has the added benefit of treating BPH symptoms 4, 5, 6, 7.
- Tadalafil may be a better option for patients with ED and BPH, as it can address both conditions simultaneously 5, 6, 7.
- The choice between Tadalafil and Sildenafil ultimately depends on the individual patient's needs and medical history 7.