Does chronic use of Losartan (angiotensin II receptor antagonist) require tapering when discontinuing?

Losartan Discontinuation: No Tapering Required

Losartan does not require tapering when discontinuing after chronic use. Unlike medications that cause significant withdrawal syndromes, losartan can typically be stopped abruptly without adverse effects related to discontinuation.

Understanding Losartan Pharmacology

Losartan is an angiotensin II receptor blocker (ARB) with the following pharmacological properties:

• Rapid absorption, reaching maximum concentrations 1-2 hours after administration 1
• Converted to active metabolite E-3174, which has a half-life of 6-9 hours 1
• Linear, dose-proportional pharmacokinetics that don't substantially change with repetitive administration 1

These properties contribute to losartan's favorable discontinuation profile, as it doesn't cause rebound hypertension or withdrawal symptoms when stopped abruptly.

Evidence on Discontinuation

Unlike many other medication classes, there is no specific guideline recommending tapering of losartan or other ARBs when discontinuing. This contrasts with:

1. Medications requiring tapering:

   • Benzodiazepines: Require gradual tapering to prevent withdrawal symptoms including rebound anxiety, hallucinations, seizures, and rarely death 2
   • Proton pump inhibitors: May benefit from tapering to prevent rebound acid hypersecretion 2
   • Cholinesterase inhibitors like donepezil: Require tapering over 2-4 weeks to prevent acute cognitive decline and withdrawal symptoms 3
   • Biologics for ankylosing spondylitis: Abrupt discontinuation can lead to relapses in 60-74% of patients 2

2. Losartan's discontinuation profile:

   • No evidence of withdrawal syndrome
   • No rebound hypertension documented in clinical studies
   • No tapering recommendations in major clinical guidelines or drug information resources 4, 1, 5, 6

Clinical Approach to Losartan Discontinuation

When discontinuing losartan:

1. Monitor blood pressure: While tapering is not required, monitoring blood pressure after discontinuation is prudent to ensure it remains controlled, especially if another antihypertensive is being substituted.

2. Consider underlying condition: If losartan is being used for conditions beyond hypertension (e.g., heart failure, diabetic nephropathy), ensure appropriate alternative therapy is instituted if needed.

3. Patient education: Inform patients to report any significant symptoms after discontinuation, though these are not expected with losartan.

Important Considerations

• Special populations: No special discontinuation protocols are needed for elderly patients or those with mild to moderate renal dysfunction 5
• Pregnancy: Losartan should be avoided in pregnancy, particularly in the second and third trimesters due to risk of fetal toxicity 1
• Combination therapy: If losartan is used with other medications that do require tapering (e.g., beta-blockers), those medications should be tapered according to their specific protocols

Conclusion

Unlike many other medication classes that require careful tapering to prevent withdrawal syndromes or rebound effects, losartan can be discontinued without a formal tapering schedule. This is due to its pharmacokinetic profile and lack of documented withdrawal or rebound phenomena in clinical studies.