What is the days supply for a Z-Pak that contains six azithromycin 250 mg tablets, with directions of 500 mg on the first day, followed by 250 mg once daily until gone?

To calculate the days supply for the Z-Pak containing six azithromycin 250 mg tablets, we can break down the dosage instructions provided. On the first day, the patient is directed to take a total of 500 mg, which is achieved by taking two tablets (each tablet being 250 mg). This means that after the first day, the patient has used up 2 out of the 6 tablets, leaving 4 tablets remaining.

For the subsequent days, the directions specify that the patient should take 250 mg once daily. Thus, with the remaining 4 tablets, the patient can take one tablet each day for the next 4 days.

Putting this all together, the initial day counts as one day of treatment with the remaining tablets allowing for an additional 4 days of treatment. Therefore, the total supply will last for 5 days: 1 day for the initial higher dose and 4 days for the lower daily dose.

This confirms that the correct days supply for the medication is indeed 5 days.