Mexiletine Antacids

ADM INI STERI NG TOCAIN IDE AN D M EXILETIN E Tocainide and mexiletine are administered at 8-hour intervals and with food (or an antacid) to prevent gastrointestinal upset. In addition, administering tocainide with food may offer some protection gainst toxicity because the absoq> tion rate is slowed in the presence of food. 

Mexiletine interacts with antacids, but the interaction is unlikely to be clinically important (48). 

The rate of absorption of mexiletine is slowed by the antacid al-masilate and atropine and hastened by metoclopramide, but the extent of the absorption is unaltered. 

The antacid almasilate (Gelusil), given one hour before a single 400-mg dose of mexiletine, resulted in a slight delay in absorption (time to maximum concentration prolonged from 1.7 to 2.9 hours), but had no effect on the extent of absorption in healthy subjects. ... 

Herzog P, HoltermUller KH, Kasper W, Meinertz T, Trenk D, Jahnchen E. Absorpticn of mexiletine after treatment with gastric antacids. BrJ Clin Pharmacol ( 9S2) 14,746-7. 

When digoxin was given with 30 mL of an aluminium/magnesium hydroxide antacid and mexiletine, the digoxin AUC was approximately halved. As mexiletine , (p.931) does not appear to interact with digoxin the interaction was attributed to the antacid. ... 

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