His kidneys will not recover completely
This condition is called CKD chronic
kidney disease
But the progession of the disease can be slowed down
Remember
creatinine just indicates function of the kidneys not the reason why the kidneys are getting damaged
He being bp patient, he may be having kidney disease since 9 yrs ,
We can use of tabs to slowed down the kidney disease
Remember most of the kidney patients will be losing protein through the urine which like poison to the kidney
So we need to reduce that loss
Next Steps
to basic urine test - routine/microscopy, urine PCR/ACR(wch ever available at your place)
Health Tips
rest is alrdy explained by my fellow colleagues in the comment section