Polyneuropathies that develop with prolonged use of sulfanilamide drugs are due to their inhibitory effect on the activity of a number of enzymatic systems, leading to chronic hypoxia in both the nerve trunks and the tissues they innervate . Especially often polyneuropathies occur with prolonged use of the anti-TB drug isoniazid , as well as barbiturates. This circumstance dictates the need for prophylactic administration of vitamin WB to all patients receiving isoniazid . The peculiarities of drug polyneuropathies are the predominance of acroparesthesia (less often pain) and motor disorders in the hands, as well as a pronounced neurodystrophic component. Described polyneuropathy in case of poisoning furadoninom , delagilom , emetine and a number of other medicines.