Optimer Pharmaceuticals has received US Food and Drug Administration (FDA) approval for Dificid (fidaxomicin) tablets for the treatment of Clostridium difficile-associated diarrhoea people aged 18 years or older.

The approval of the antibacterial drug is based on results from two randomised, multicentre, double-blind trials which demonstrated its efficacy.

The studies were conducted in North America and enrolled 1,164 adults. They showed that 88% of patients who received the drug experienced a clinical response, compared to 86% of vancomycin-treated patients.

The adverse events seen included nausea, vomiting, abdominal pain, gastrointestinal haemorrhage, anaemia and neutropaenia.

Clostridium difficile-associated diarrhoea is a bacterial infection in the lining of the gut that can cause severe diarrhoea, inflammation of the colon and, in some cases, death.