Gabapentin at a low dose of 100 mg has a Tmax (pharmacology) (time to Cmax (pharmacology)) of approximately 1.7 hours, while the Tmax increases to 3 to 4 hours at higher doses. Food does not significantly affect the Tmax of gabapentin and increases the Cmax of gabapentin by approximately 10%. The Tmax of the modified-release dosage (medicine) (IR) formulation of gabapentin enacarbil (as active gabapentin) is about 2.1 to 2.6 hours across all doses (350-2,800 mg) with single administration and 1.6 to 1.9 hours across all doses (350-2,100 mg) with repeated administration. Conversely, the Tmax of the modified-release dosage (medicine) (XR) formulation of gabapentin enacarbil is about 5.1 hours at a single dose of 1,200 mg in a fasted state and 8.4 hours at a single dose of 1,200 mg in a fed state.. Which doses have the longest hours to take Gabapentin, 350-2800 or 350-2100?