Drop in relapse rate of MS by combination therapy of three different phosphodiesterase inhibitors.

Phosphodiesterase inhibitors (PDEIs), when used in combination, synergistically suppress TNFa production by various cells and also suppress experimental demyelination at very low concentrations. We conducted a pilot study to determine whether the combination of three PDEIs suppresses the relapse of MS at the usual therapeutic doses. Of the 12 relapsing remitting MS, the mean relapse rate/year dropped remarkably (from 3.08+3.32 to 0.92+1.86) after PDEI treatment. Seven out of 12 (58.3%) were relapse-free in the follow up period (499+142 days). The combination of three PDEIs can be safe and useful strategy for the future treatment of MS.