Insomnia, hyperactivity, stress, anxiety Valerian causes addictive effects in some patients taking barbiturates. it possibly potentiates (1) sedative effects of catnip, hops, Kona, kava, and passionflower and (2) the sedative effects of alcohol. do not give to patients who are pregnant or breast-feeding. evidence of toxicity includes difficulty walking, hypothermia, and increased muscle relaxation. possible adverse reactions include hepatotoxic effects upon withdrawal