My 10 month old daughter, in her early months, trialed erythromycin for its side effect of making the stomach empty faster. It worked well for awhile, but she was subsequently diagnosed with eosinophilic gastro. and stopped all meds. She has always been a poor eater, and her MAX intake is 20 oz. Most days she gets more along the lines of 18.

Currently she is taking zithromax for an ear infection. Since starting it, she has wanted a bottle every 2 1/2 hours and is taking close to 30 oz. Which is wonderful for her, especially since she is failure to thrive. BUT, her pepcid was also recently increased. So I guess my question is does zithromax have the same side effect on gastric emptying as erythromicin? I know that they are in the same family of drugs, so I am trying to figure out if her sudden increase in appetite is related to the antibiotic, or her pepcid increase.
Thanks in advance!

Melissa, these are both macrolide antibiotics and although the side effects on the stomach for the zithromax are lighter than the older erythromycin, it is still a possibility. I have a call in to Pfizer to double check this. Either way I'll let you know. The erythromycin would probably do this much better.
Graham Ph.C.

On speaking with pfizer's medical information research team, they tell me that they have no concrete evidence that zithromax increases gastric emtying rate or any of the physiological markers to indicate that it can do this. It does admit however that there was a study that showed a possibility of this.
Good question, Graham Ph.C.