LosartanLosartan Potassium

About Losartan

Losartan blocks the receptor for angiotensin II, a hormone that tightens blood vessels, so vessels relax and blood pressure falls. The label covers high blood pressure in adults and children 6 and older; lowering the risk of stroke in people with high blood pressure and left ventricular hypertrophy (a thickened heart wall), although there is evidence that this benefit does not apply to Black patients; and kidney disease in type 2 diabetes with a history of high blood pressure, a raised blood creatinine and a lot of protein in the urine. Adults usually start at 50 mg once a day (25 mg if they may be low in fluid, for example on a diuretic, or have mild to moderate liver impairment), up to 100 mg once a day; children start at 0.7 mg per kg, up to 50 mg. For stroke risk, hydrochlorothiazide is added and the doses raised step by step. Kidney impairment alone needs no dose change.

The boxed warning is fetal toxicity: drugs acting on the renin-angiotensin system can injure and kill a developing baby, so losartan is stopped as soon as pregnancy is detected. It must not be taken by anyone allergic to it or with aliskiren in diabetes, and combining it with other drugs that block this system, such as an ACE inhibitor, is generally avoided. Blood pressure can drop too far in people low in salt or fluid, and kidney function and potassium can change, so both are checked periodically. Angioedema (swelling of the face, lips, tongue or throat that can block the airway) has been reported, sometimes in people who had it with an ACE inhibitor, and in June 2025 the Cozaar label added swelling of the intestine. In high blood pressure, dizziness, upper respiratory infections, a stuffy nose and back pain were the most common side effects; in diabetic kidney disease, tiredness, low blood pressure, anemia, high potassium and low blood sugar were among them.

Arbli, a 10 mg per mL suspension approved in March 2025, is labeled for the same uses and doses as the tablets, and the Cozaar label tells pharmacists how to make a 2.5 mg per mL suspension from tablets. It is not known whether losartan passes into breast milk; the Arbli label advises against breastfeeding during treatment and for 2 days after the last dose. Some lots of losartan and of the hydrochlorothiazide combination were recalled in 2018 and 2019 for nitrosamine impurities, and the FDA advised patients to keep taking their medicine until the pharmacist could replace it. Losartan with hydrochlorothiazide (Hyzaar and generics) is a separate prescription for high blood pressure, not for starting treatment unless it is severe, and for stroke risk with a thickened heart wall; it is not started in liver impairment, and its use in children is not established. The hydrochlorothiazide adds warnings: it is not for people who make no urine; it can lower potassium, sodium and magnesium and affect blood sugar, cholesterol, uric acid (gout) and calcium; sudden decreased vision or eye pain can signal a glaucoma that, untreated, can cause permanent vision loss; it can worsen lupus; and it is linked to non-melanoma skin cancer, so sun protection and skin checks are advised.

Taking Losartan

How to take it

Usually once a day, with or without food, at about the same time each day, though some people take it twice a day. Shake Arbli for 20 seconds before each dose and measure it with an oral syringe or dosing cup; shake a pharmacy-made suspension before each use too.

If you miss a dose

Take it as soon as you remember, unless it is almost time for the next dose; then skip the missed dose and carry on as usual. Do not take a double dose.

Storage

Tablets at room temperature, tightly closed, protected from light and moisture, not in a bathroom. Arbli at room temperature in its original bottle, protected from light, used within 60 days of opening; a pharmacy-made suspension in the refrigerator, used within four weeks.

Interactions to know about

Potassium supplements, potassium salt substitutes and other medicines that raise potassium add to the risk of high potassium, and it raises lithium levels. NSAIDs such as ibuprofen and naproxen can blunt its effect and strain the kidneys. It is not taken with aliskiren in diabetes, combining it with an ACE inhibitor or another ARB is generally avoided, and rifampin lowers its levels.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Losartan differs from pharmacy to pharmacy

Generic losartan has many makers and costs pharmacies little, so much of a quote is the dispensing fee and markup, which differ between pharmacies. A prescription that names Cozaar or Hyzaar and blocks substitution is priced as a brand.

Arbli has no generic, so it is priced as a brand. A suspension the pharmacy mixes from tablets keeps only four weeks in the refrigerator, so it is filled more often than tablets.

Ways to pay less for Losartan without insurance

• Ask for generic losartan tablets, and make sure the prescription does not block substitution.
• Ask whether losartan is on the pharmacy’s flat-price generic list, and compare more than one pharmacy.
• If you take 100 mg a day, ask the prescriber to write it as one 100 mg tablet rather than two 50 mg tablets, and ask for a ninety-day supply once your dose is stable.
• If Arbli is prescribed, ask the prescriber whether tablets or a pharmacy-made suspension would suit, and ask the maker whether a savings program applies to someone paying cash.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Losartan

1. 1.When will my potassium and kidney function be checked?
2. 2.Should I avoid potassium supplements, salt substitutes or ibuprofen with it?
3. 3.What should I do if I become pregnant or plan to?
4. 4.If my losartan is ever recalled, should I keep taking it until you can replace it?

Related medications