Somdev has been struggling since winning the Delhi Open challenger title and failed to cross the first round hurdle in five consecutive tournaments on the ATP tour.
Also sliding in the ATP ranking ladder was India's second best singles player, Yuki Bhambri, who lost four spots to be 153.
The tall and big serving Saketh Myneni though jumped seven places to be 262.
In the doubles, Leander Paes continued to be India's best ranked player and the only one in top-10 at number nine. Davis Cupper Rohan Bopanna was next best at number 14.
Left-handed Delhi boy Divij Sharan suffered a loss of four places to take the 71st spot this week.
In the WTA rankings, Sania Mirza maintained her eighth rank in the doubles chart.