What could be the cause of burning when urinating and frequent urge to the toilet?

Alexander: Hello! I have a burning sensation when urinating and frequent urge. Bought 5 days ago pills sildenafil North Star (prod. Leningrad. region), blue, 100 mg. Everything was fine, took 1 tablet, day before yesterday accidentally drank 2 tablets. Now often run to the toilet, there was a burning sensation. Today went rarely. May take? What do you think? Urine is normal color, there is no selection, the partner constant. I'm 33. Thank you.

The answer of the doctor-doctor: Hello, Alexander! Burning may be associated with inflammation of the reproductive system, urolithiasis. I recommend to pass urinalysis, total smear+PCR+secret of the prostate, to perform ultrasound prostate, bladder and kidney problems and to consult a urologist in person. I wish you health!