Drug Information Q&A Q14. How long do the effects of a drug last?
Answer
The duration of effect of a drug depends on the type of drug. Therefore, the interval between doses and dosages are determined according to the duration of effect of the drug. To ensure safe and effective treatment, please follow the prescribed dosage and administration.
Explanation
Once a drug enters the body, it is carried throughout the body by the bloodstream.
In order for a drug to work effectively in the target area, the concentration of the drug in the blood (blood concentration) must reach a level that is appropriate for the drug to be effective (effective concentration).
For drugs taken three times a day, while the effective concentration of the active ingredient lasts for 4 to 6 hours after administration, the drug is gradually broken down in the liver or dissolved in the urine and excreted outside the body, causing the concentration in the blood to decrease and the drug to become ineffective. Therefore, it is necessary to take the next dose of the drug 6 to 8 hours after taking it, before the blood concentration drops and the drug loses its effect.
The dosage and administration of a drug is an important rule that must be followed in order to maintain effective blood levels of the drug and to use it safely, in terms of its effective time (the time during which its effective concentration is maintained).
If a drug is taken in excess of the prescribed dosage, the blood concentration of the drug will increase unnecessarily and may even cause harm.
On the other hand, if the dosage is too low, the blood concentration will not rise to an effective level, and the drug will not be fully effective.
Therefore, physicians prescribe the most appropriate dose of a drug that is safe and effective for the patient, taking into consideration the patient's symptoms, weight, age, and other factors. This is called the "appropriate dosage of a drug. It is very important for patients to follow the "proper dosage" prescribed by the doctor or pharmacist.
If a patient takes a drug too early, the next drug may enter the body before the blood concentration of the drug has fully decreased, and the blood concentration may rise too high. As a result, the blood concentration may rise too high, resulting in the same condition as if you had taken a large number of pills. On the other hand, if a patient forgets to take a medicine, the blood concentration of the drug will drop and its effect will not be maintained.
It is important to take the prescribed amount of medication at the prescribed time.
Chart/Column
14｜Effective Concentration of Medicines to be Taken Alone
Recommended contents
-
Let's have fun learning about basic knowledge of drugs and how to use them correctly with Capsule-kun!
-
Information for patients and their families on health conditions and provision of medical care.
-
As people get older, the number of medicines they take increases, causing side effects and making it difficult for them to take their medicines properly.
