Timing of Famotidine After Mylanta
You can take famotidine immediately—there is no required waiting period after taking Mylanta.
Why No Waiting Period Is Necessary
The concern about timing between antacids and other medications typically relates to absorption interference through chelation or pH-dependent absorption mechanisms. However, famotidine does not require a waiting period after antacid administration for the following reasons:
Pharmacokinetic Profile of Famotidine
- Famotidine begins raising gastric pH within 30 minutes of administration and reaches peak plasma concentrations at 2.5 hours 1
- The onset of acid inhibition occurs approximately 35 minutes after famotidine administration 2
- Famotidine's acid-inhibiting effects last approximately 6 hours, making twice-daily dosing effective 3
Complementary Mechanisms of Action
- Mylanta (aluminum/magnesium hydroxide antacid) works immediately by neutralizing existing stomach acid, while famotidine works by blocking future acid production at the parietal cell level 1
- These are complementary rather than competing mechanisms—the antacid provides immediate symptom relief while famotidine prevents further acid secretion 4
- In fact, hydrotalcite (a similar antacid) was shown to relieve reflux symptoms faster than famotidine within the first 45 minutes, with both showing equal efficacy between 60-120 minutes 4
Practical Clinical Approach
Optimal Dosing Strategy
- Take famotidine 1 mg/kg/day divided in 2 doses (or standard adult dose of 20 mg twice daily) 1
- For nighttime acid suppression, famotidine before bedtime is particularly effective at controlling nocturnal acid breakthrough 3
- Early evening dosing (immediately after dinner) provides longer duration of secretory inhibition (10.1 hours) compared to late evening dosing (7.1 hours) 5
Important Limitations to Consider
- All H2-receptor antagonists including famotidine develop tachyphylaxis within 6 weeks of continuous use, significantly limiting their effectiveness for long-term therapy 6, 7
- PPIs are more effective than famotidine for treating esophageal GERD syndromes and healing esophagitis 6, 7
- Standard-dose famotidine is ineffective for preventing NSAID-related gastric ulcers, though it reduces duodenal ulcers 6, 7
When Famotidine Is Specifically Preferred
If you are on dual antiplatelet therapy (aspirin plus clopidogrel), famotidine is strongly preferred over PPIs because it does not interfere with clopidogrel's antiplatelet activity 6, 3, 7
For short-term symptom relief or on-demand therapy, famotidine's rapid onset (35 minutes) makes it useful when immediate effect is needed alongside the antacid 7, 2
Common Pitfall to Avoid
Do not continue famotidine beyond 6 weeks without reassessing efficacy due to tachyphylaxis development—if long-term therapy is anticipated, choose a PPI instead 6