Losartan Uses, Side Effects & Interactions

Losartan is an angiotensin II receptor blocker (ARB) which is used to relax the blood vessels in order to help lower blood pressure in the body. Instead of working at a muscular or tissue level, this medication blocks the natural substances created by the body that tighten the blood vessels. It may take up to 3-6 weeks before Losartan can take its full effects, so be sure to take your medication regularly to help ensure that it starts working as quickly as possible. Do not stop taking your medication once you start feeling better, as this can cause your symptoms to return at a more severe rate.

Indications and Usage

Losartan is sold under the name Cozaar. Losartan is used to treat high blood pressure, usually as a combination of medications and treatments to help reduce the likelihood of heart attack or stroke. In some cases, this medication may be used to treat kidney problems or diabetes. This medication is usually prescribed in tablet form, but your pharmacist can offer an alternative if your child is unable to swallow the pill. In most cases, patients will be started on a low dose, which is increased as necessary to manage your condition.

Losartan Dosage

For Adults

Adults treating hypertension are typically given initial of 25 mg. Doses may be increased up to 100 mg per day as necessary. Those with depleted intravascular volume will also be limited to 25 mg per day. Hypersensitive patients and those who are using this medication to treat type II diabetes will be given 50 mg per day in conjunction with other medications to help manage their condition.

For Children

Children over 6may be given up to 50 mg per day to help treat hypertension. Those under the age of 6 should not use Losartan.

Children with severe kidney issues may not be able to take Losartan as the medication cannot be cleared from their system efficiently. Talk to your doctor about this risk before your child starts using this medication to help avoid a serious reaction.

For Pregnant Women

Pregnant womenshould not use Losartan due to the increased risk of birth defects in their child. Those who are breastfeeding may also need to avoid this medication due to the risk of passing the drug to their child. Talk to your doctor about these concerns if you become pregnant while on Losartan.


Usual Dosage

Special Dosage

Hypertension is treated with 50 mg daily, or 25 mg in those with depletion of intravascular volume

Adult doses range from 25-100 mg per day depending on the condition requiring treatment.

Children over 6 are to be given 50 mg per day, and should not be given more than 100 mg per day. Hypersensitive patients and those treating diabetes should be limited to 50 mg per day. Losartan is not to be taken by those who are pregnant, breastfeeding, or children with serious kidney issues

Losartan Side Effects

Side effects for those suffering from Losartan are not very common. The most regularly reported side effect of this medication is an increase in infections such as colds or the flu which occurs in up to 8 percent of users. Other side effects reported more commonly include dizziness in up to 3 percent of users, nasal congestion in 2 percent and back pain in 2 percent of patients. These side effects are not serious and will only need to be reported to your doctor if they begin to interfere with your ability to function.

Types of Side Effects


Common Side Effects

Infection, dizziness, nasal congestion, and back pain.

Common Side Effects for Those with Diabetic Nephropathy

Diarrhea, fatigue, anemia, increase in potassium levels, low blood pressure and weight gain

Serious Side Effects

Unexplained rash, itching, blisters or peeling skin


Dizziness, fainting, fast or slow heartbeat


Because of the dizziness and light headedness that is associated with Losartan, patients should take care when moving around or getting up from a resting position. Take the time to steady yourself to help make sure that you do not fall and injure yourself. You should not drive nor do any tasks that require your full attention until you know how severely these side effects will affect you. Do not drink alcohol while on Losartan as this can make these side effects worse.

You should not take diuretics, lithium, celecoxib, aspirin, or NSAIDs while using Losartan. These medications can negatively interact with your medication, and may increase the effects of the medication to an unsafe level. Let your doctor know about any medications or over the counter products you are taking, including supplements that may include potassium to help avoid a potentially dangerous reaction once you start your prescription.

Same Category