This disclosure generally relates to catheters, methods of enhancing the patency of an intravascular catheter and compositions, methods, devices and kits relating to the infusion of a catheter lock solution into an indwelling catheter. Disclosed compositions, methods, devices and kits aid in diminishing the effects of microbial infection in catheters and occlusion of the catheters. A representative lock solution includes about 10% sodium citrate and about 1.5% benzyl alcohol. The solution has a density approximating the density of blood for retention of the solution in a catheter during the lock period.