Have a healthy Spring Festival
Floxacin antibacterial drugs mainly include levofloxacin, moxifloxacin and ciprofloxacin, which belong to quinolone antibacterial drugs, which act on the DNA of sensitive bacteria, inhibit the activity of topoisomerase, the key enzyme required for the replication, transcription, repair and reorganization of bacterial DNA and exert bactericidal activity, floxacin antibacterial drugs have certain advantages in respiratory tract infections, urinary tract infections, abdominal and pelvic infections, but different varieties in infectious diseases The clinical status and indications are also different, such as moxifloxacin is unique in respiratory tract infections, but the effect of urinary tract infections is not good.
Floxacin drugs are concentration-dependent antimicrobial drugs, that is, their antibacterial effect is related to the highest blood concentration that can be obtained, therefore, this type of drug usually advocates the total daily dose to be given at one time in order to obtain a higher peak concentration, such as levofloxacin and moxifloxacin are administered once a day, but ciprofloxacin needs to be administered 2-3 times a day, why is this?
To understand this problem, we must first know several pharmacokinetic parameters, such as blood peak concentration (Cmax), area under the curve (AUC), drug half-life (T1 2), etc., drugs administered once a day, in addition to having a high blood peak concentration (Cmax) and area under the curve (AUC), must also meet two conditions: first, the half-life is long enough, and second, it is necessary to have a long enough post-antibiotic effect (PAE), so as to ensure that even if the drug is administered once a day, It can also play a good sterilizing effect.
The half-life of a drug is the time it takes for the plasma drug concentration to drop by half, and the length of the drug can reflect the speed of drug elimination in the body.
The so-called post-antibiotic effect refers to the effect that the bacterial growth is still continuously inhibited for a certain period of time when the concentration of antibiotics in the body is lower than the minimum inhibitory concentration (MIC) or completely eliminated by the body, which is the unique response of antimicrobial drugs to pathogenic microorganisms. Generally speaking, after the removal of antibiotics, some bacteria are not completely killed, but they are in a state of being blinded and comatose, that is, they are "disabled", and such bacteria are not lethal to the human body.
Levofloxacin and moxifloxacin have a long half-life, levofloxacin has a half-life of 6-8 hours, moxifloxacin has a half-life of about 12 hours, and ciprofloxacin has a shorter half-life of only 4 hours, levofloxacin and moxifloxacin also have a longer PAE, so they only need to eat once a day, while ciprofloxacin needs to be eaten 2-3 times a day, which is the reason.