Losartan is one of the most commonly prescribed medications worldwide. The FDA approved this medicine for the treatment for hypertension (high blood pressure) in adults and some children. People with type 2 diabetes who have high blood pressure also benefit from its kidney-protecting properties. The drug blocks angiotensin II, a natural chemical that tightens blood vessels. This blocking action reduces vasoconstriction, so blood pressure drops.

What is Losartan?

Losartan tablets belong to the angiotensin II receptor blocker (ARB) family. 

This prescription medication helps blood flow smoothly through your body by relaxing blood vessels. It acts as an angiotensin II receptor blocker that stops certain natural substances from constricting your blood vessels resulting in lowering blood pressure. It comes in 12.5mg, 25mg, 50mg, and 100mg strengths.

How Does Losartan Work?

The medication targets AT1 receptors in blood vessels, heart, kidneys, and adrenal glands by blocking angiotensin II from binding to them. This action stops blood vessels from narrowing and reduces aldosterone production, which helps widen blood vessels and lower water retention.

Uses of Losartan

Doctors prescribe this medicine to treat high blood pressure in adults & children above 6 years. It protects the kidneys in patients who have type 2 diabetes and hypertension. The medication also lowers stroke risk in patients with high blood pressure and left ventricular hypertrophy.

How & When to Take Losartan

• You should take one losartan tablet daily, with or without food. 

• Take the whole losartan tablet with a glass of water. Do not crush or chew the tablet.

• Take the medicine at the same time each day.

• Always take the exact dose as prescribed by your doctor.

• Do not stop the medicine in between as discontinuing may cause adverse reactions.

Side Effects of Losartan

Common side effects:

• Dizziness 

• Headaches

• Upper respiratory infections

• Muscle or joint pain

• Nausea 

• Diarrhoea.

Serious reactions:

• Facial/throat swelling

• Breathing difficulties

• Kidney problems.

Dosage for Losartan

Treatment for high blood pressure in adults begins with 50 mg daily and may increase to 100 mg depending on blood pressure response. 

Children between 6-16 years who have hypertension receive doses based on their weight - typically 0.7 mg/kg daily (not exceeding 50 mg).

Can We Take Losartan Daily?

Losartan needs daily intake to keep blood pressure under control effectively. Blood pressure often drops within the first week, but patients experience the medication's full benefits after 3-6 weeks of consistent use.

Precautions 

• Your doctor needs to know about:

• Any medication allergies

• Plans to become pregnant or breastfeed (not safe during pregnancy)

• Existing liver or kidney issues

• Diabetes 

• Heart conditions.

• Avoid potassium supplements and excessive salt during the treatment

• Avoid quick sitting or standing from a lying position to prevent dizziness

• Avoid alcohol as it increases the risk of low blood pressure and dizziness. 

What If You Missed a Dose?

You should take the missed dose when you remember it unless your next scheduled dose is approaching. Skip the forgotten dose and stick to your regular schedule in that case. Taking two doses together is never recommended.

What If You Overdose?

An overdose can cause dizziness, drowsiness, and palpitations. Contact emergency services immediately if you suspect an overdose. 

Caution With Other Drugs: Interactions

Several medications interact with losartan. 

• Alcohol

• ACE inhibitors like lisinopril or enalapril 

• Aliskiren

• Antifungals like ketoconazole or fluconazole

• Certain contraceptive pills

• Cyclosporine

• Lithium 

• NSAIDs like aspirin or ibuprofen

• Other angiotensin II receptor blockers

• Potassium supplements 

• Rifampin

• Salt substitutes 

• Trimethoprim.

Losartan vs Lisinopril

Blood pressure medications losartan and lisinopril work differently though they target the same system. Lisinopril belongs to the angiotensin-converting enzyme (ACE) inhibitor class, while losartan is an angiotensin II receptor blocker (ARB).

Each medication's effect on the renin-angiotensin system follows distinct mechanisms:

• Lisinopril blocks the body's production of angiotensin II, which prevents blood vessels from constricting

• Losartan blocks angiotensin II from binding to receptors and keeps vessels from narrowing

Both medicines lower systolic blood pressure effectively - lisinopril reduces it by approximately 20.2 mmHg and losartan by 17.2 mmHg. Research shows lisinopril substantially improves insulin sensitivity, though losartan doesn't share this effect.

Lisinopril helps patients recover after heart attacks and treats heart failure. Losartan reduces stroke risk in patients with high blood pressure and left ventricular hypertrophy, and it treats diabetic nephropathy.

Both medications share common side effects like cough, dizziness, fatigue and diarrhoea. All the same, research suggests that taking losartan twice daily might help patients achieve lower systolic blood pressure compared to once-daily doses.

FAQs

1. What is losartan used for?

   Doctors prescribe losartan to manage high blood pressure in adults and children over six years old. This medicine reduces stroke risk in patients with hypertension and left ventricular hypertrophy. Patients with type 2 diabetes can benefit from its ability to treat kidney disease when they also have high blood pressure.

2. How does losartan help control blood pressure?

   Losartan works as an angiotensin II receptor antagonist by blocking natural chemicals that constrict blood vessels. Blood vessels relax and widen as a result, which helps blood flow smoothly through the body. Patients usually see full results after 3-6 weeks.

3. Can losartan protect the kidneys in diabetes?

   Losartan is an effective way to protect the kidneys in patients with type 2 diabetes. The medicine reduces protein loss through the kidneys and lowers high blood pressure, which slows disease progression. Research trials confirm that it effectively prevents end-stage renal disease.

4. What time should I take Losartan tablets?

   Take losartan once daily at the same time each day. New patients should consider taking it before bedtime since dizziness can occur. You can take this medication with or without food.

5. What are the common side effects of losartan?

   Common reactions:

   • Dizziness when standing up

   • Headaches

   • Nausea

   • Diarrhoea

   • Muscle or joint pain.

6. Who should avoid taking losartan?

   Pregnant women should not take losartan because it can harm unborn babies. The medication isn't safe for people with severe liver problems, those with losartan allergies, or diabetic patients taking aliskiren.

7. Can losartan cause dizziness or low blood pressure?

   Losartan can cause dizziness or low blood pressure (hypotension). This happens especially when you have to stand up quickly. If you feel dizzy:

   • Lie down immediately to avoid fainting

   • Sit until the sensation passes

   • Stand up gradually when recovering

   • Avoid driving or using machinery.

   Your body will adjust to the medication and these symptoms typically improve. Dehydration, vomiting, diarrhoea, or excessive sweating can make these effects worse.

8. Can I take losartan with other blood pressure medicines?

   Losartan works well with calcium channel blockers (like amlodipine) and thiazide diuretics. Doctors often prescribe triple therapy that combines these medications for resistant hypertension. But you should avoid taking losartan with:

   • ACE inhibitors

   • Direct renin inhibitors

   • Potassium-sparing diuretics.

9. Is losartan safe during pregnancy?

   No you must avoid losartan throughout pregnancy. The medicine can harm unborn babies, particularly during the second and third trimesters. It reduces amniotic fluid levels, which can affect the foetus and lead to:

   • Kidney damage

   • Lung development problems

   • Growth restriction.

   Women need to stop taking losartan as soon as they find out they're pregnant.

10. What should I do if I miss a dose of losartan?

    You should take the missed dose when you remember, unless it's almost time for your next scheduled dose. After that, continue with your regular schedule. Never take a double dose to make up for a missed pill.