How do doctors and pharmacists...?

Question

... determine how many milligrams and doses of medicine you should take?

Answer 1

Age, gender,body weight, side effects,toxicity safety margin and urgency of action jointly decide the dose and mode of administration

Answer 2

doctors particularly take into account what is known as a patient history ie age sex race medications previously taken etc, then they do a diagnosis to identify the cause and provide a treatment such as a drug.

the drug as u can imagine is based on the weight of the patient(and many other factors) as is done in the clinic especially for an anesthetic, hence they often need your wieght when u get admitted, for reasons as to prevent over dose and not to reach the lethal toxic dose.

however, an ordinary gp often prescribes the therapeutic dose based on the common average population(done previously in clinical trials) eg amoxcillin 500mg, and this is most of the time within the therapeutic range and thus makes us better,

hope that helps ;-)

Answer 3

In the US, drugs in development have dose-ranging studies as part of the phase II clinical trials. That gives a large amount of information. Additional information becomes available in post-marketing studies. Then it's just a matter of matching the clinical situation with the drug. Factors like the size of the patient have to be taken into account, and doses have to be adjusted in, for instance, patients with renal failure, but dosing overall tends to be pretty standardized, and we just try to get to about a standard dosage with some level of convenience (for instance, in pediatrics, it's nice for dosages to come out close to a teaspoon or some such that the parent can manage to measure).

Answer 4

These things have been determined by previously done drug trials. All new medications are required by the FDA to have dosing recommendations.

Answer 5

I believe drugs come with instructions. And there is a pharmaceutical dictionary that has pictures of pills and recommended dosages and other relevant informations.