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Old 07-15-2012
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Drug Drug dose, half life, and efficacy

A 500 mg dose of a drug has therapeutic efficacy for 6hr. If the half life of the drug is 8h, for how long the 1g dose be effective?

A. 8h
B. 12h
C. 14h
D 16h
E. 24h

pls explain how you got to the answer as well because this problem is driving me nuts
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Old 07-15-2012
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14 hours I guess?
8 hours till there's only 500 mg of the drug in the body and from then on, 6 more hrs as mentioned in the question stem.
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Old 07-15-2012
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C- 14 hours
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Old 07-16-2012
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plz can somebody explain:sorry:
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Old 07-16-2012
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Quote:
Originally Posted by curiousmind View Post
plz can somebody explain:sorry:
The half-life of the drug is 8 hrs, so it takes 8 hrs for a 1000-mg dose to become half (500 mg) and as the question mentions, a dose of 500 mg is effective for 6 hrs.
Therefore, the dose will have a therapeutic effect for 6 more hours.That means it will be therapeutic for (8+6= 14) hours overall.
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