No, but it's generally recommended and is easy to obtain. However, It's the least important of the SN, anti-emetic, and antacid combo. The normal levels of acid in your stomach convert the sn into nacl(table salt). So by taking the antacid, you're lowering the acid levels in your stomach, thereby decreasing the amount of sn that gets "lost".
Sn isn't something to mess around with FYI, so please only attempt if you're absolutely sure that you want to die. Best wishes.