Yes, you can overdose on azithromycin. This commonly occurs when trying to make up for a skipped dose. If you miss a dose, you can take it when you remember. But if it is close to the next dose, skip it to avoid taking a double dose. An increased level of azithromycin can worsen side effects like diarrhea or irregular heart rhythm. If you have already taken an overdose of azithromycin, contact your healthcare provider, your local poison control center, or call 9-1-1.