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Why Is The Maximum Daily Dose Of A Drug The Same For A Small Or Large Person?
Question: Why is the maximum daily dose of a drug the same for a small or large person? For instance, 300 mg Zantac per day is the maximum recommended daily dose for 100 or a200 lb person.
Brief Answer:
Information
Detailed Answer:
Hello and welcome,
There are a number of factors that determine how a drug is metabolized and distributed. Dosages for many medications for children and adults differ because of body weight. And some medications differ in adults based on body weight, such as IV lidocaine. So it really is based on the type of drug and what happens to it in the body. And dosing usually decreases in the elderly or people with liver or kidney function impairment because of slower metabolism.
What we were taught in pharmacology in medical school is that for some medications, as long as the person is an adult, dosing generally doesn't need to change for someone who is obese because that increase in weight is due to fat tissue, and that doesn't change the distribution of the medication. So we don't increase a dose for someone who is overweight. But we might decrease the dose for a very small person who is the size of a child.
Regards
Information
Detailed Answer:
Hello and welcome,
There are a number of factors that determine how a drug is metabolized and distributed. Dosages for many medications for children and adults differ because of body weight. And some medications differ in adults based on body weight, such as IV lidocaine. So it really is based on the type of drug and what happens to it in the body. And dosing usually decreases in the elderly or people with liver or kidney function impairment because of slower metabolism.
What we were taught in pharmacology in medical school is that for some medications, as long as the person is an adult, dosing generally doesn't need to change for someone who is obese because that increase in weight is due to fat tissue, and that doesn't change the distribution of the medication. So we don't increase a dose for someone who is overweight. But we might decrease the dose for a very small person who is the size of a child.
Regards
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Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
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