How to reduce creatinine levels in blood ?

There are many reasons for increased creatinine and urea levels in the blood. Urea and creatinine are the endotoxins usually caused by reduced excretion of the protein metabolism end products via urine.
Creatinine is a substance that is produced during the body's natural activity (metabolism).
It is usually excreted (got rid of) from the body through the kidneys. If the kidneys start to become diseased, for whatever reason, the level of creatinine rises in the blood stream.
It is the level in the blood stream that is usually measured in renal function tests and I presume that it is this level that you are referring to.
The normal level of creatinine is usually 60 to 110 micromoles per litre but the exact figures can vary from lab to lab.
Having a low level of blood creatinine indicates nothing more than an efficient and effective pair of kidneys.
A further test of kidney function is to collect all the urine passed over a period of twenty-four hours and then to compare the amount of creatinine in the blood to the level in the blood stream (creatinine clearance test).
This can look at the efficiency of the kidneys and is only usually done if there is an indication of a problem with renal function.
In normally functioning kidneys, the level of creatinine in the urine compared to the blood should be high as it is being passed out efficiently.
Conversely, if the level in the urine is low, with a high blood creatinine level, this in an indication of a problem, for which a consultant physician is usually involved.
I hope that this information helps you understand the significance of a low creatinine level.