Excessive ingestion of lithium causes drowsiness, slurred speech and vomiting, among other symptoms, and poisons the central nervous system, which is dangerous as the required dosage of lithium to treat bipolar disorder is only slightly lower than the toxic dosage.
ɛksˈɛsɪv ɪndʒˈɛstʃən ʌv lˈɪθiəm kˈɔːzᵻz dɹˈaʊsinəs, slˈɜːd spˈiːtʃ ænd vˈɑːmɪɾɪŋ, ɐmˌʌŋ ˈʌðɚ sˈɪmptəmz, ænd pˈɔɪzənz ðə sˈɛntɹəl nˈɜːvəs sˈɪstəm, wˌɪtʃ ɪz dˈeɪndʒɚɹəs æz ðə ɹᵻkwˈaɪɚd dˈoʊsɪdʒ ʌv lˈɪθiəm tə tɹˈiːt baɪpˈoʊlɚ dɪsˈoːɹdɚɹ ɪz ˈoʊnli slˈaɪtli lˈoʊɚ ðɐn ðə tˈɑːksɪk dˈoʊsɪdʒ.