BSN Tracker

losartan

Brand: Cozaar

⚠ BBW Prototype Drug
Drug Class: angiotensin II receptor blocker (ARB)
Drug Family: antihypertensive
Subclass: AT1 receptor antagonist
Organ Systems: cardiovascularrenal

Mechanism of Action

Selectively blocks AT1 receptors, preventing angiotensin II-mediated vasoconstriction and aldosterone release; does not increase bradykinin, so no cough.

AT1 receptor (angiotensin II type 1 receptor)

Indications

  • hypertension
  • diabetic nephropathy in type 2 diabetes
  • heart failure (ACE-I intolerant)
  • LVH reduction
  • Marfan syndrome (off-label)

Contraindications

  • pregnancy
  • concomitant aliskiren use in diabetes or CrCl <60
  • dual blockade with ACE inhibitor (generally avoid)

Adverse Effects

Common

  • dizziness
  • hyperkalemia
  • hypotension

Serious

  • AKI
  • angioedema (rare)
  • teratogenicity

Pharmacokinetics (ADME)

Absorption 33% bioavailability; active metabolite EXP-3174 has 15x more potency
Distribution high protein binding
Metabolism hepatic CYP2C9 and CYP3A4 to active metabolite EXP-3174
Excretion biliary 60%, renal 35%
Half-life 2 hours (losartan), 6-9 hours (EXP-3174)
Onset 1-3 hours
Peak 6 hours
Duration 24 hours
Protein Binding 99%
Vd 34 L

Drug Interactions

Drug / Agent Mechanism Severity
potassium-sparing diuretics additive hyperkalemia major
fluconazole CYP2C9 inhibition reduces conversion to active metabolite moderate
rifampin CYP inducer increases metabolism, reduces efficacy moderate

Nursing Considerations

  1. No cough — use when ACE-I cough is intolerable
  2. Monitor BP, K+, creatinine
  3. Confirm absence of pregnancy; teratogenic
  4. LIFE trial: superior to atenolol for LVH reduction in hypertension

Clinical Pearls

  • First ARB; active via metabolite EXP-3174
  • Only ARB with specific indication for diabetic nephropathy and LVH
  • Uricosuric effect — lowers uric acid (unique among ARBs)

Safety Profile

Pregnancy contraindicated
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.

Angiotensin II Receptor Blocker (ARB) Diabetic Nephropathy In Type 2 Diabetes Heart Failure (ACE-I Intolerant) Hypertension LVH Reduction Marfan Syndrome (off-label)
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