This is post-void dribbling, usually few drops of urethral urine leaking out shortly after voiding; not really a medical problem, and no medical solutions. 

Measures I recommend: 

1. wait longer to finish

2. shake or milk out urethral urine

3. small absorptive pad or tissues to soak up urine & prevent wetness & smell

As all investigations are within normal limits, this is just a variant of "being normal"

There is a minute amount of urine remaining in the bulbar urethra, and that should be miked out at the end of micturition.

Like Shomik said, at the end of milking the urine out, a small tissue can be used to wipe out the drops.

However, what must be impressed upon is that this is not a pathological condition necessitating treatment.

First some questions:

Is the dribbling during daytime with or without urinary urgency?

Further urological history? Childhood urological problems?

What is his maximum flowrate? Is flowcurve normal or with a (very) prolonged end?

Is the postmicturition dribbling depending on voiding position (standing or sitting)?

How does the voiding drinking diary look like, including the report of dribbling?

Which prescriptions have been unsuccesful?

Note: 5 drops (is 0,25mL) give already a large wet spot on cotton!

23years old is not a boy, and in addition to the important questions asked by Dr.Peter F W M Rosier ,  how long is his complaint?

all previous are right but i recommend to use parasympatholytics to diminish the unvoluntary detrousal contractions and many cases were controlled on this regimen for 2 ms.

Further  history:

On  diuretics? Could  it  be  a  side  effect  of  diuretics?

Onset  should  be  known  and  the  lifestyle  changes  prior  to  and  immediately  following  onset  investigated.

It  looks more  like  a neurogenic  problem  than  anatomic.

Has the patient been told to press upwards in the perineum behind the scrotum?

Is the uroflow curve normal?

Many questions need to be answered.. .I would do a uroflowmetry, a determination of residual urine by ultra sound, a cystometry ..Ask him to write down for 2 days what really happens day and night. A cystoscopy is unlikely to answer the question.

Prof. Jacques Susset

thanks for your responses...

well there were no history of diuretics, had a complain from few years he barely remember.had advised milking pressur and pads.

UFM was done, qmax was 19ml/sec curze looks ok to me there were slight prolonged ending of micturation.