Can tamsulosin (alpha-blocker) and tadalafil (phosphodiesterase type 5 inhibitor) be taken together?

From the Guidelines

Taking tamsulosin and tadalafil together is not recommended due to the higher side effect risk, as stated in the 2021 AUA guideline for the management of lower urinary tract symptoms attributed to benign prostatic hyperplasia 1. When considering the use of these medications, it's crucial to weigh the potential benefits against the risks, particularly the increased risk of side effects.

• Tamsulosin is an alpha-blocker commonly used to treat benign prostatic hyperplasia (BPH) symptoms.
• Tadalafil, on the other hand, may be prescribed for erectile dysfunction or BPH, depending on the dosage. The combination of these medications can lead to enhanced side effects, primarily due to their pharmacological properties.
• It's essential for healthcare providers to carefully evaluate the medical history and current condition of the patient before deciding on such a combination. Given the guidance from the 2021 AUA guideline, the combination of tamsulosin and tadalafil should be avoided, if possible, to minimize the risk of adverse effects 1. In clinical practice, if a patient is already on one of these medications and the other is deemed necessary, the healthcare provider might consider alternative treatment options or closely monitor the patient for potential side effects, adjusting the treatment plan as needed.
• Patient education on recognizing and reporting side effects, such as dizziness or lightheadedness, is also crucial. Ultimately, the decision to use tamsulosin and tadalafil together should be made with caution and under the guidance of a healthcare professional, taking into account the latest clinical guidelines and the individual patient's health status 1.

From the FDA Drug Label

Caution is advised when alpha adrenergic blocking agents including Tamsulosin Hydrochloride Capsules are co-administered with PDE5 inhibitors. Alpha adrenergic blockers and PDE5 inhibitors are both vasodilators that can lower blood pressure. Concomitant use of these two drug classes can potentially cause symptomatic hypotension

Tadalafil is a PDE5 inhibitor. The use of tamsulosin and tadalafil together may cause symptomatic hypotension. Therefore, caution is advised when taking these two medications together 2.

From the Research

Combination Therapy of Tamsulosin and Tadalafil

• The combination of tamsulosin and tadalafil has been studied for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) with or without erectile dysfunction (ED) 3, 4, 5, 6.
• Studies have shown that the combination of tamsulosin and tadalafil can improve LUTS, erectile function, and quality of life compared to monotherapy 4, 5, 6.
• The efficacy and safety of tadalafil alone or in combination with tamsulosin for the management of LUTS/BPH and ED have been evaluated, and the results suggest that daily tadalafil, in particular 5 mg, is safe and effective in treating LUTS/BPH and ED 5.

Efficacy of Combination Therapy

• A meta-analysis of 12 randomized controlled trials (RCTs) found that the combination of tadalafil and tamsulosin was more effective in improving total International Prostate Symptom Score (IPSS), maximum flow rate (Qmax), and quality of life (QoL) compared to monotherapy 4.
• Another study found that the combination of tamsulosin and tadalafil improved LUTS, erectile function, and patient QoL more than tamsulosin monotherapy with a comparable safety profile 7.
• The combination of tamsulosin and tadalafil has been shown to be effective in improving IPSS voiding, Qmax, and QoL, but the benefits of combination therapy for ED remain unclear 4.

Safety of Combination Therapy

• The safety of the combination of tamsulosin and tadalafil has been evaluated, and the results suggest that the combination is well-tolerated with an acceptable adverse events rate 5, 6.
• A study found that the adverse reactions in the combined treatment group were significantly higher than those in the monotherapy group, but none of the 12 RCTs reported serious adverse events 4.
• The combination of tamsulosin and tadalafil has been shown to be safe and effective, but further RCTs are required to provide more direct evidence 3.