Tamsulosin + Solifenacin

No, Tamsulosin + Solifenacin doesn't cause retrograde ejaculation. Retrograde ejaculation occurs when there is an abnormal ejaculation, reduced ejaculate volume and ejaculation force, absence of seminal emission and backflow of the seminal fluid from the urethra to the bladder. 

Tamsulosin + Solifenacin blocks receptors in the prostate, prostatic capsule, prostate urethra, and bladder neck. When these receptors are blocked, smooth muscle relaxation occurs in the bladder neck and prostate, decreasing the urinary outflow resistance in men.

Yes, it is safe to use Tamsulosin + Solifenacin. It should be used strictly under a doctor's supervisions and one must comply with all the recommendations. One must not take more or less of Tamsulosin + Solifenacin or take it more or less frequently as per his/her will. In some people, however, Tamsulosin + Solifenacin may cause certain side effects like blurred vision, sleepiness, difficulty in ejaculating, sore throat, weakness, etc. Please inform your doctor if you suffer from any of these side effects. 

Tamsulosin + Solifenacin might be given for the treatment of erectile dysfunction (ED). The exact mechanism of how it works in erectile dysfunction is not known but It is presumed that it works by improving libido, erection, and overall sexual function.

No, Tamsulosin + Solifenacin doesn't cause weight gain. Weight gain can be prevented or managed by eating small, frequent meals and adding some physical activity to the routine.