Concerns Switching from Tamsulosin to Tadalafil

Answer

Thanks so much for reaching out to us with your question, it's a good one!

While it might seem like you're getting a much higher dose when switching from 0.8 mg of tamsulosin (generic for Flomax) to 5 mg of tadalafil (generic for Cialis), it's important to know that these are completely different medications from different drug classes. Their effects and how they work in the body are not directly comparable based on milligrams alone.

Different Medications, Different Mechanisms

Tamsulosin is an alpha-1 adrenergic blocker, while tadalafil is a phosphodiesterase-5 (PDE-5) inhibitor. Both are used to treat benign prostatic hyperplasia (BPH), which causes urinary symptoms like weak stream, frequent urination, and urgency. However, they work in very different ways.

• Tamsulosin works by relaxing the smooth muscle in the prostate and bladder neck, improving urine flow. It starts working quickly and is often considered a first-line medication for BPH (i.e., is the first medication used to treat the condition).
• Tadalafil is most commonly known for its use in treating erectile dysfunction, but it's also FDA-approved for daily use to treat BPH. It improves urinary symptoms by relaxing the smooth muscle in the lower urinary tract, although it does not directly shrink the prostate or improve urine flow rate as much as alpha-blockers do.

Why the Switch?

It's not clear, based on your question, exactly what side effects you had on tamsulosin.

You mentioned sensitivity to light, which isn't a common side effect, but of course, everyone can react differently to medication.

It's possible your doctor considered the switch as a precaution due to a rare but real side effect of tamsulosin called intraoperative floppy iris syndrome (IFIS). This can be a concern and PDE-5 inhibitors like tadalafil do not carry this risk.

Regardless, you were switched and that's the reason for your question.

Is 5 mg of Tadalafil Too Much?

Not at all. 5 mg once daily is the standard dose of tadalafil for treating BPH (and for daily erectile dysfunction treatment). It may seem higher than 0.8 mg, but again, they’re not comparable by milligrams alone as they work on entirely different pathways.

Effectiveness and What to Expect

Clinical studies have shown that tadalafil improves urinary symptoms in men with BPH, though not necessarily by increasing urine flow. It's particularly beneficial for patients who also experience erectile dysfunction.

While tamsulosin typically provides quicker relief of urinary symptoms, tadalafil is a great option for many men, especially when side effects or specific risks (like IFIS) need to be avoided.

As with any medication change, make sure you monitor how you feel. Let your doctor know if your urinary symptoms worsen or if you experience side effects like headache, flushing, or nasal congestion, which can occasionally occur with tadalafil.

Summary

Even though the dose numbers in milligrams are quite different, you're not getting 'more medicine', just a different one with a different mode of action.

Both tamsulosin and tadalafil are effective treatments for BPH, and your doctor likely made the change based on your personal medical history.

Thanks again for reaching out!