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.
Amitriptyline is a tricyclic antidepressant that is widely used to treat chronic neuropathic pain (pain due to nerve damage). It is recommended as a first line treatment in many guidelines. Neuropathic pain can be treated with antidepressant drugs in doses below those at which the drugs act as antidepressants.