I was on Tamsulosin for 10 years (2014-2023); the thought came to me that if Tamsulosin (0.4 mg capsule) relaxed muscles in my prostate and bladder, then it might also result in other “non-urinary-related” effects elsewhere in my body. So, I did some digging……

One side-effect that never occurred to me was that Tamsulosin (an alpha-blocker, used to treat urinary issues such as BPH), can result in deterioration of sleep quality (obstructive events, apneic episodes, and sleep-disordered breathing) due to the relaxing of muscles in the throat and airway.
> Moran 2016: “Reversible Exacerbation of Obstructive Sleep Apnea by Tamsulosin,” Respir Med Case Rep. 2016 Oct 14;19:181–186.

If you search further, you’ll find other possible side-effects of alpha‑blockers, due to their action on alpha‑1 adrenergic receptors, leading to vasodilation and smooth muscle relaxation: low blood pressure, dizziness, headaches, fatigue, and abnormal or retrograde ejaculation, and more.