How and when: Overdosage can cause hyperthyroidism,
thyroid dysfunction, tremors, irritability, hot flushes, tachycardia, insomnia and arterial hypertension.
Plasma caffeine levels are usually in the range of 2-10 mg/L in coffee drinkers, 12-36 mg/L in neonates receiving treatment for apnea,
and 40-400 mg/L in victims of acute Overdosage.