Colistin monotherapy versus combination of colistin with a β-lactam or rifampicin for the treatment of serious infections in the ICU due to multidrug-resistant Gram-negative bacteria

The resistance of Gram-negative strains in the ICU is a growing problem. Recent studies suggest in-vitro synergy of colistin with β-lactams and colistin with rifampicin against these strains. However, there is controversy on the efficacy of the drug provided either as monotherapy or in combination with these drugs in critically ill patients.