Medications can affect creatinine by (1) reducing kidney filtration/perfusion, causing a true increase, or (2) altering tubular secretion, increasing the measured level. Common examples include NSAID pain relievers (risk increases with dehydration or long-term use), certain antibiotics and contrast agents in susceptible patients, and predictable small shifts after starting some blood pressure medications. The key is not to stop drugs on your own; instead, review timing, dose, hydration status, comorbidities, and urine findings with a clinician—especially if the rise is rapid or symptoms appear.