What are the effects of taking Tadalafil (Cialis) 20 milligrams every 3 days?

From the Guidelines

Taking Cialis 20 mg every 3 days is not a standard dosing regimen and lacks substantial research support, therefore, it is not recommended without consulting a healthcare provider. Cialis (tadalafil) is typically prescribed for erectile dysfunction at doses ranging from 5-20 mg, with varying administration schedules depending on intended use. For on-demand use, it's often taken before anticipated sexual activity, while for daily therapy, lower doses (2.5-5 mg) are typically used 1. The 20 mg dose taken intermittently every 3 days is not a standard regimen in clinical guidelines. Tadalafil has a long half-life of approximately 17.5 hours, which means it remains active in the body for 36-72 hours, which may be why some consider an every-third-day dosing schedule. However, this approach lacks substantial research support. Some key points to consider when taking Cialis include:

• The American College of Physicians recommends that clinicians initiate therapy with a PDE-5 inhibitor in men who seek treatment for erectile dysfunction and who do not have a contraindication to PDE-5 inhibitor use 2.
• Treatment with an oral PDE-5 inhibitor demonstrated statistically significant and clinically relevant improvements in sexual intercourse and erectile function in patients with ED.
• The choice of a specific PDE-5 inhibitor should be based on the individual preferences of men with erectile dysfunction, including ease of use, cost of medication, and adverse effects profile 2. Patients should consult their doctor before adopting any specific dosing schedule, as factors like age, kidney function, liver health, and medication interactions can affect appropriate dosing. Side effects may include headache, indigestion, back pain, muscle aches, flushing, and nasal congestion.

From the FDA Drug Label

5. 10 Concomitant Use of Potent Inhibitors of Cytochrome P450 3A4 (CYP3A4)

Tadalafil is metabolized predominantly by CYP3A4 in the liver. The dose of tadalafil tablets for use as needed should be limited to 10 mg no more than once every 72 hours in patients taking potent inhibitors of CYP3A4 such as ritonavir, ketoconazole, and itraconazole [see Drug Interactions (7. 2)].

The FDA drug label does not provide information on taking Cialis 20 mg every 3 days. However, it does mention that the dose of tadalafil tablets for use as needed should be limited to 10 mg no more than once every 72 hours in patients taking potent inhibitors of CYP3A4.

• The label does not explicitly address the dosage of 20 mg every 3 days.
• The recommended dosage for patients without potent CYP3A4 inhibitors is not provided in the given text.
• Therefore, no conclusion can be drawn regarding the safety and efficacy of taking Cialis 20 mg every 3 days 3.

From the Research

Research on Taking Cialis 20 mg Every 3 Days

• There are no studies that directly investigate the effects of taking Cialis 20 mg every 3 days 4, 5, 6, 7, 8.
• However, a study on the efficacy and safety of tadalafil once daily found that tadalafil 2.5 or 5 mg once daily was effective and safe for the treatment of erectile dysfunction, with a favorable risk-benefit balance 6.
• Another study compared the use of tadalafil daily vs on-demand for erectile dysfunction and found that patients taking tadalafil daily for 12 weeks scored higher in International Index for Erectile Dysfunction-Erectile Function domain scores, although the difference may not be clinically significant 5.
• A long-term safety and tolerability study of tadalafil found that tadalafil was safe and well tolerated for patients with erectile dysfunction, with no consistent pattern of serious adverse events assessed as causally associated with tadalafil administration 8.

Dosage and Frequency

• The studies found that tadalafil 2.5 or 5 mg once daily was effective and safe for the treatment of erectile dysfunction 6.
• Tadalafil 10 or 20 mg taken as needed up to once daily for 18 to 24 months was also found to be safe and well tolerated 8.
• However, there is no direct evidence on the effects of taking Cialis 20 mg every 3 days, and the optimal dosage and frequency for this regimen are unclear 4, 5, 6, 7, 8.