Patients w/ epilepsy, history of convulsion or predisposing factors for epilepsy. Avoid concomitant use of other N-methyl-D-aspartate (NMDA)-antagonists, eg, amantadine, ketamine or dextromethorphan. Carefully monitor patient whose urine pH may be increased by factors eg, drastic changes in diet, massive indigestion of alkalising gastric buffers; renal tubulary acidosis, severe UTI w/ proteus bacteria. Closely supervise patients w/ recent MI, uncompensated CHF (NYHA III-IV), or uncontrolled HTN. May affect ability to drive or operate machinery. Not recommended in patients w/ severe hepatic impairment. Pregnancy. Do not breastfeed during therapy. Paed patients.