Sorry to be a buzzkill, but there is no definitive answer to who-is-the-most-reactive-element-amongst-all, because it takes two to tango. One could ask which element is the most reactive with Sodium? The answer then is Fluorine, not Caesium. Or, perhaps you want to know which element is the most reactive with Nitrogen. Its Lithium! Shocker!
1 Day 1: reduce dosage of amitriptyline to 75 mg/day. 2  Day 8: reduce dosage of amitriptyline to 50 mg/day. 3  Day 15: reduce dosage of amitriptyline to 25 mg/day. 4  Day 22: reduce dosage of amitriptyline to 10 mg/day. Day 8: reduce dosage of amitriptyline to 50 mg/day. 2  Day 15: reduce dosage of amitriptyline to 25 mg/day. 3  Day 22: reduce dosage of amitriptyline to 10 mg/day. 4  Day 29: stop administration of amitriptyline.
Initial Dosage for Adults: For outpatients 75 mg of amitriptyline HCl a day in divided doses is usually satisfactory. If necessary, this may be increased to a total of 150 mg per day. Increases are made preferably in the late afternoon and/or bedtime doses.