Skip to Content
Is it time for a new insulin treatment? Learn more >>

Losartan Disease Interactions

There are 4 disease interactions with losartan:


Ar Antagonists (Includes Losartan) ↔ Hypotension

Severe Potential Hazard, High plausibility

Applies to: Dehydration, Hyponatremia, hemodialysis

Angiotensin II receptor (AR) antagonists can cause symptomatic hypotension in patients with an activated renin-angiotensin system, such as volume- and/or sodium-depleted patients. Therapy with AR antagonists should be administered cautiously in such patients and in those predisposed to hypovolemic or hyponatremic states (e.g., patients on diuretic therapy, especially if high doses were used or if recently instituted; those on dietary salt restriction; renal dialysis patients). Volume and/or sodium depletion should be corrected prior to initiating therapy with AR antagonists, and the patient should be hemodynamically stable. Ideally, patients at risk for excessive hypotension should initiate AR antagonist therapy under close medical supervision, preferably with a lower dose, and followed closely for the first 2 weeks of treatment and whenever the dosage of AR antagonist or diuretic is increased.


  1. "Product Information. Cozaar (losartan)." Merck & Co, Inc, West Point, PA.
  2. Goldberg MR, Bradstreet TE, McWilliams EJ, Tanaka WK, Lipert S, Bjornsson TD, Waldman SA, Osborne B, Pivadori L, Lewis G, et al "Biochemical effects of losartan, a nonpeptide angiotensin II receptor antagonist, on the renin-angiotensin-aldosterone system in hypertensive patients." Hypertension 25 (1995): 37-46
  3. Tikkanen I, Omvik P, Jensen HA "Comparison of the angiotensin II antagonist losartan with the angiotensin converting enzyme inhibitor enalapril in patients with essential hypertension." J Hypertens 13 (1995): 1343-51
View all 22 references

Ar Antagonists (Includes Losartan) ↔ Chf

Moderate Potential Hazard, Moderate plausibility

Applies to: Congestive Heart Failure

Angiotensin II receptor (AR) antagonists can cause renal impairment in patients whose renal function depends on the activity of the renin-angiotensin-aldosterone system. In addition, symptomatic hypotension can occur in susceptible individuals, which may compromise renal and myocardial perfusion. In patients with severe congestive heart failure (CHF), treatment with AR antagonists has been associated with oliguria and/or progressive azotemia and, rarely, renal failure, myocardial ischemia, and death. Therapy with AR antagonists should be initiated cautiously in patients with severe CHF, especially when accompanied by volume and/or sodium depletion. In patients who experience a decline in renal function, discontinuation of AR antagonist therapy is usually not required provided there is symptomatic improvement of the heart failure and renal deterioration is well-tolerated. Transient hypotension is also not a contraindication to further treatment with AR antagonists, since therapy can usually be reinstated without difficulty after blood pressure stabilizes.


  1. Saine DR, Ahrens ER "Renal impairment associated with losartan." Ann Intern Med 124 (1996): 775
  2. Doig JK, MacFadyen RJ, Sweet CS, Lees KR, Reid JL "Dose-ranging study of the angiotensin type I receptor antagonist losartan (DuP753/MK954), in salt-deplete normal man." J Cardiovasc Pharmacol 21 (1993): 732-8
  3. Holwerda NJ, Fogari R, Angeli P, et al. "Valsartan, a new angiotensin II antagonist for the treatment of essential hypertension: efficacy and safety compared with placebo and enalapril." J Hypertens 14 (1996): 1147-115
View all 27 references

Ar Antagonists (Includes Losartan) ↔ Renal Artery Stenosis

Moderate Potential Hazard, Moderate plausibility

Applies to: Renal Artery Atherosclerosis

In patients with bilateral renal artery stenosis or renal artery stenosis in a solitary kidney, angiotensin II receptor (AR) antagonists may reduce renal perfusion to a critically low level. Increases in serum creatinine or blood urea nitrogen have been reported with ACE inhibitors, a class of drugs that also block the renin-angiotensin-aldosterone system. Although there are no long-term data on the use of AR antagonists in patients with renal artery stenosis, a similar effect should be anticipated. Renal function should be monitored closely for the first few weeks of therapy.


  1. "Product Information. Benicar (olmesartan)." Sankyo Parke Davis, Parsippany, NJ.
  2. "Product Information. Cozaar (losartan)." Merck & Co, Inc, West Point, PA.
  3. "Product Information. Diovan (valsartan)." Novartis Pharmaceuticals, East Hanover, NJ.

Losartan (Includes Losartan) ↔ Renal/Liver Disease

Moderate Potential Hazard, High plausibility

Applies to: Liver Disease, Biliary Obstruction, Renal Dysfunction

Losartan is converted in the liver to an active carboxylic acid metabolite and several inactive metabolites, and both parent drug and metabolites are eliminated by the kidney (35%) as well as by biliary excretion (60%). Dosage adjustments are not necessary in patients with renal impairment unless they are also volume-depleted, in which case therapy should be initiated under medical supervision. In patients with cirrhosis, however, significantly increased plasma concentrations of parent drug and active metabolite have been reported. Therapy with losartan should be initiated cautiously at a reduced dosage (50%) in patients with impaired liver function.


  1. Sachinidis A, Ko Y, Weisser P, Meyer zu Brickwedde MK, Dusing R, Christian R, Wieczorek AJ, Vetter H "EXP3174, a metabolite of losartan (MK 954, DuP 753) is more potent than losartan in blocking the angiotensin II-induced responses in vascular smooth muscle cells." J Hypertens 11 (1993): 155-62
  2. Sica DA, Lo MW, Shaw WC, Keane WF, Gehr TWB, Halstenson CE, Lipschutz K, Furtek CI, Ritter MA, Shahinfar S "The pharmacokinetics of losartan in renal insufficiency." J Hypertens 13 Suppl (1995): s49-52
  3. Ohtawa M, Takayama F, Saitoh K, Yoshinaga T, Nakashima M "Pharmacokinetics and biochemical efficacy after single and multiple oral administration of losartan, an orally active nonpeptide angiotensin II receptor antagonist, in humans." Br J Clin Pharmacol 35 (1993): 290-7
View all 9 references

You should also know about...

losartan drug Interactions

There are 482 drug interactions with losartan

losartan alcohol/food Interactions

There is 1 alcohol/food interaction with losartan

Drug Interaction Classification

The classifications below are a general guideline only. It is difficult to determine the relevance of a particular drug interaction to any individual given the large number of variables.

Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.

Do not stop taking any medications without consulting your healthcare provider.

Disclaimer: Every effort has been made to ensure that the information provided by Multum is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. Multum's information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill, knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2016 Multum Information Services, Inc. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.