(Reuters) - Pfizer Inc said a clinical study found its Lyrica nerve pain treatment did not affect sperm production in men taking the pill.

The drugmaker conducted the study of more than 200 men as a requirement of the U.S. Food and Administration for approving Lyrica, which is one of Pfizer's biggest-selling medicines.

Lyrica, also known as pregabalin, is used for diabetic nerve pain, pain after shingles and seizures for epilepsy sufferers, among other conditions. Pfizer last week won a U.S. court case protecting Lyrica's patent that stands to keep generic rivals at bay until 2018.

In a separate study conducted to fulfill European requirements, Pfizer said the trial of patients with anxiety found a low number of symptoms developed after discontinuing Lyrica.