Question

A physician orders Gantrisin (sulfisoxazole) 2 g po tid

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3 days and then 1.5 g tid for the rest of the month. The available medication is sulfisoxazole 500 mg tablets.

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How many tablets should be administered per dose for the medication for the first 3 days?

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How many tablets should be administered per dose when the dose is 1.5 g?

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How many mg of sulfisoxazole will the patient receive per day for the first 3 days?

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How many mg of sulfisoxazole will the patient receive per day for the next 27 days?

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How many grams of sulfisoxazole will the patient receive over the first week?

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How many tablets should be dispensed for the entire month?

Answer 1

Available dose is 500mg per tablet.

1) No. of tablets to be administered per dose for first 3 days = 4 tablets.

This is because 1 tab is 500 mg and to get 2 g per dose, 4 tablets to be given.

2) No. of tablets to be administered per dose when the dose is 1.5 g = 3 tablets.

3) For first 3 days patient is receiving 2 g three times a day.

Therefore, per day patient receives 6 g.

That is, the patient will receive 6000 mg of sulfisoxazole per day for the first 3 days.

4) For the next 27 days patient is receiving 1.5 g per dose 3 times a day.

Therefore, per day patient receives 4.5 g.

That is, patient will receive 4500 mg per day for next 27 days.

5) One week = 7 days.

First 3 days, patient receives 18 g. ( ie, 6 g/ day × 3 days).

Next 4 days, patient receives 18 g. ( ie, 4.5 g/ day × 4 days).

Therefore, over the first week patient receives 36 g of the medication.

6) For first 3 days,

One day patient takes 12 tablets. ( ie, 4 tablets/ dose × 3 times).

Therefore, for 3 days patient takes 36 tablets. ( ie, 12 tablets/ day × 3 days)

For the next 27 days,

One day patient takes 9 tables. (ie, 3 tables / dose × 3times)

Therefore, for 27 days, patient takes 243 tablets. (ie, 9 tables / day × 27 days)

Hence, the no.of tablets to be dispensed for the entire month is 36 +243

= 279 tablets.