Extracorporeal Removal of Drugs: Peritoneal Dialysis and Hemodialysis

Dialysis removes waste products and drugs via diffusion and filtration into dialysis fluid, with the dialyzer acting as an artificial kidney. Blood or body fluid is equilibrated with dialysis fluid across a semipermeable membrane, allowing waste to diffuse into the dialysate. The dialysate is balanced in electrolytes and osmotic pressure, typically containing water, dextrose, potassium, sodium, chloride, bicarbonate, acetate, and calcium.

In peritoneal dialysis, the peritoneal membrane in the abdomen acts as a filter with a surface area of 1–2 m² for diffusion. A catheter is surgically placed into the peritoneal cavity, where dialysis fluid is instilled and later drained periodically. Peritoneal dialysis is performed at home, enabling self-treatment without a dialysis machine, making it especially suitable for diabetic patients.

Peritoneal dialysis uses the abdominal peritoneal membrane as a filter and is performed at home for self-treatment. Hemodialysis uses a dialysis machine with an artificial membrane and requires vascular access through an arteriovenous fistula or graft. Hemodialysis is more efficient for drug removal, making it preferred for rapid detoxification in overdose or poisoning cases.

Hemodialysis treatment frequency ranges from once every two days to three times a week, with each session lasting 2–4 hours. Factors such as residual renal function, body weight, and muscle mass influence the duration of dialysis and drug dosing. Treatment is typically performed in a dialysis center and is preferred in emergency situations.

For patients with compromised renal function, dosage adjustments of concurrent medications may be necessary during extracorporeal drug removal. Understanding drug clearance and elimination is critical for proper dosing. Factors like residual renal function affect how quickly drugs are removed and how medications should be adjusted during treatment.

Patients with end-stage renal disease or those experiencing drug overdose require extracorporeal methods to eliminate accumulated drugs and metabolites. Hemoperfusion, hemofiltration, and dialysis are the primary techniques to rapidly remove harmful substances without disrupting the patient's fluid and electrolyte balance.

Hemodialysis requires vascular access, often achieved through an arteriovenous fistula or graft. Blood flows from the body to the dialysis machine through this access point, where waste materials are removed by diffusion and ultrafiltration before the blood is returned to the body.