Which antihypertensive medication, Amlodipine, Clonidine, Atenolol, or Telmisartan, is most likely being dialyzed and cleared during Hemodialysis (HD)?

Atenolol is the Medication Being Dialyzed

Atenolol is the antihypertensive agent being cleared during hemodialysis, causing the paradoxical blood pressure increase at the end of dialysis sessions. 1

Why Atenolol is the Culprit

Dialyzability Profile

• Atenolol is highly dialyzable with hemodialysis clearance ranging from 119.5 to 311 mL/min, removing approximately 24% of the drug during a 6-hour treatment session 1
• The half-life of atenolol during hemodialysis is reduced to 4.6 hours compared to its normal prolonged half-life in ESRD patients 1
• Atenolol clearance by hemodialysis has tripled over the past 30 years with improved dialysis technology, making this effect even more pronounced with modern high-efficiency dialysis 1

Clinical Mechanism of Blood Pressure Rebound

• The "rebound" phenomenon occurs when atenolol is removed during dialysis, leading to loss of beta-blockade and subsequent blood pressure elevation toward the end of treatment 1
• This paradoxical hypertension at the end of dialysis is a well-documented consequence of removing dialyzable beta-blockers 1
• Studies specifically note that when hemodialysis was used for atenolol, an increase in blood pressure was observed after treatment in the majority of cases 1

Why the Other Medications Are NOT Being Dialyzed

Amlodipine

• Amlodipine is NOT dialyzable due to extensive protein binding (approximately 93%) and hepatic metabolism 2
• The pharmacokinetics of amlodipine are not significantly influenced by renal impairment or dialysis 2
• Elimination is primarily hepatic with a long half-life of 30-50 hours, making it resistant to dialytic removal 2

Telmisartan

• Telmisartan is NOT dialyzable as the majority is eliminated by biliary excretion, not renal clearance 3
• Patients with renal dysfunction can receive usual doses because the drug is not renally eliminated 3
• The hepatobiliary elimination pathway makes it completely resistant to hemodialysis removal 3

Clonidine

• Clonidine is NOT significantly dialyzable and can be administered once weekly via transdermal patch in noncompliant dialysis patients, demonstrating its resistance to dialytic clearance 4
• The ability to use weekly transdermal dosing confirms that hemodialysis does not meaningfully remove this medication 4

Clinical Management Recommendations

Immediate Solution

• Switch from atenolol to a non-dialyzable beta-blocker such as propranolol or carvedilol to maintain consistent beta-blockade throughout the dialysis session 1
• One retrospective study found that nondialyzable beta-blockers (e.g., propranolol) are associated with lower mortality risk compared to highly dialyzable beta-blockers (e.g., atenolol, metoprolol), possibly due to preserved intradialytic protection against arrhythmias 1

Alternative Approach if Continuing Atenolol

• Administer atenolol after hemodialysis rather than before, using supervised thrice-weekly dosing to ensure consistent drug levels 5, 6
• Studies demonstrate that supervised administration of atenolol (25 mg) following hemodialysis three times weekly effectively controls hypertension without increasing intradialytic hypotension 5
• This approach is particularly valuable for noncompliant patients and takes advantage of atenolol's prolonged half-life in ESRD 5, 7

Important Caveat

• While switching to non-dialyzable agents prevents drug removal, be aware that carvedilol has been associated with higher mortality rates compared to metoprolol in one study, attributed to increased intradialytic hypotension 1
• The key is matching drug dialyzability to the patient's intradialytic blood pressure pattern: avoid non-dialyzable medications if frequent intradialytic hypotension occurs 1