Losartan

What it is

Losartan is an angiotensin II receptor blocker available on prescription. Rather than preventing angiotensin II from forming, it blocks the receptor it acts on, so vessels stay relaxed and blood pressure falls. It is used for high blood pressure, and it also increases urinary excretion of uric acid, which makes it useful when gout accompanies hypertension.

A usual adult range, not a national label — the dose and the timing differ by country and by product.

Used for

• Hypertension
• Gout

Approved uses differ by country — some of these may be off-label or unapproved where you live.

What to know while taking it

It can be taken with or without food, at a steady time of day. Ibuprofen reduces its effect and adds kidney strain, and spironolactone or potassium and magnesium aspartate supplements can push potassium higher, since losartan itself tends to raise it. Follow-up usually covers potassium, creatinine and eGFR, and uric acid where gout is part of the picture. It is not used in pregnancy, as drugs acting on this system damage the developing kidneys.

When to see a doctor

See a doctor for muscle weakness, tingling or an irregular heartbeat, which can signal high potassium, or for a marked fall in urine output. Fainting, or dizziness that does not pass on standing up slowly, is also worth reviewing. Pregnancy or plans for it are a reason to see a doctor promptly.

Worth knowing

• Can raise potassium
• Not during pregnancy

Markers to watch

• Potassium
• Creatinine
• eGFR
• Uric acid

Nutrients affected

• potassium — raised by (Potassium)