Asymptomatic period followed by delayed toxicity can suggest MAO-I toxicity
urine immunoassays and mass spectroscopy can fail to detect MAOI (patients taking selegiline will test positive for methamphetamine)
consider ECG and chemistry panel in MAOI overdose patients who are obtunded
Monoamine oxidase inhibitor toxicity
Intoxications
Synthetic cathinone toxicity
Amphetamines
Tricyclic antidepressant toxicity
Antimuscarinics
Mescaline toxicity
Methylxanthine toxicity 