Losartan - um bloqueador do receptor de angiotensina
Cozaar
Revisado por Sid DajaniÚltima atualização por Michael Stewart, MRPharmSLast updated 2 Fev 2025
Atende aos diretrizes editoriais
- BaixarBaixar
- Compartilhar
- Language
- Discussão
- Versão em Áudio
- Add to preferred sources on Google
Take losartan once each day. You can take your doses either before or after a meal.
Any side-effects are usually mild, and can include feeling dizzy or light-headed.
Some painkillers can interfere with losartan and increase the risk of side-effects, so ask a pharmacist for advice before you buy any medicines 'over the counter'.
Do not drink grapefruit juice whilst taking losartan. It can interact with the medicine and alter its effect.
Clinical author's note: Michael Stewart 15/11/2018: Following an MHRA update, new advice has been added to this leaflet for people also taking the blood pressure medicine hydrochlorothiazide. Hydrochlorothiazide is only available in the UK in combination with other medicines used to treat high blood pressure. It may be available on its own in other countries. For more information see the warning below in 'can this medicine cause problems?' or view the Alerta MHRA.
At a glance
Losartan is a medicine often prescribed for high blood pressure, heart failure, or kidney disease linked to diabetes.
It works by blocking a substance in your body called angiotensin II, which helps lower blood pressure.
Take losartan once a day, at the same time each day, with or without food.
Tell your doctor if you are pregnant, breastfeeding, or have kidney, heart, or liver problems.
Common side effects can include feeling tired or dizzy when standing up.
Avoid certain anti-inflammatory painkillers and salt substitutes while taking this medicine.
If you are taking losartan with hydrochlorothiazide, protect your skin from the sun.
Neste artigo:
Video picks for Tratamento e prevenção de doenças cardíacas
Continue lendo abaixo
About losartan
Tipo de medicamento | Um antagonista do receptor de angiotensina II |
Usado para | High blood pressure; heart failure; kidney disease associated with diabetes |
Também chamado de | Cozaar®; |
Disponível como | Comprimidos |
Losartan is an angiotensin receptor blocker. It is also called an angiotensin-II receptor antagonist, or an AIIRA. You will have been prescribed losartan for one of the following reasons:
To lower blood pressure if your pressão arterial muito alta (hipertensão).
To help your heart if it is not beating as well as it should (insuficiência cardíaca).
To help protect your kidneys if you have kidney disease associated with type 2 diabetes mellitus.
Losartan works by blocking the effect of a substance in your body called angiotensin II. Angiotensin II causes your blood vessels to narrow and also leads to the production of another substance called aldosterone, which increases the amount of fluid in your blood. By preventing the action of angiotensin II, losartan reduces how much work your heart has to do and lowers your blood pressure. It also has a protective effect on your kidneys.
You may be prescribed losartan to take on its own, or alongside other medicines to help your condition. There is a combination tablet available called Cozaar-Comp® which contains losartan with a diuretic called hydrochlorothiazide. This combination tablet can be prescribed to people with high blood pressure to help reduce the total number of tablets that need to be taken each day.
Before taking losartan
Voltar ao conteúdoSome medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking losartan it is important that your doctor knows:
Se você está grávida ou amamentando.
If you know you have a blockage of the artery which supplies blood to your kidneys, a condition called renal artery stenosis.
Se você tiver algum problema com suas válvulas cardíacas ou músculo cardíaco.
Se você tem um problema com o funcionamento do seu fígado.
Se você estiver tomando outros medicamentos. Isso inclui quaisquer medicamentos que você esteja tomando e que estejam disponíveis para compra sem receita médica, bem como medicamentos fitoterápicos e complementares.
Se você já teve uma reação alérgica a um medicamento ou se teve qualquer outro tipo de reação alérgica.
Continue lendo abaixo
How to take losartan
Voltar ao conteúdoBefore you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about losartan and will provide you with a full list of the side-effects which you could experience from taking it.
Take losartan once each day, exactly as your doctor tells you to. There are several different strengths of tablet available. When you first start treatment your doctor may gradually increase the strength of the tablets to suit your condition. Each time you collect a fresh supply, it's a good idea to check the strength on the packet to make sure they are what you are expecting.
Try to take losartan at the same time of day each day. For most people this will be in the morning. Taking your doses at the same time each day will help you to remember to take losartan regularly.
Swallow the tablet whole with a drink of water. You can take losartan either before or after a meal.
Se você esquecer de tomar uma dose, tome-a assim que se lembrar. Se não se lembrar até o dia seguinte, pule a dose esquecida. Não tome duas doses ao mesmo tempo para compensar uma dose esquecida.
Obtendo o máximo do seu tratamento
Voltar ao conteúdoTry to keep your regular appointments with your doctor. This is so your progress can be monitored. Your doctor may want you to have some blood tests from time to time to check on your kidneys, and also how much potassium is in your blood.
If you buy any medicines, check with a pharmacist that they are suitable to take with losartan. This is because some anti-inflammatory painkillers (such as aspirin and ibuprofen) can interfere with the way it works, and also may increase the risk of side-effects.
É muito importante que você siga quaisquer orientações dietéticas e de estilo de vida que tenha recebido do seu médico, como manter uma alimentação saudável, não fumar e praticar exercícios regularmente.
If you drink alcohol, ask your doctor for advice. Your doctor may recommend that you do not drink alcohol while you are on losartan because it will increase the risk of side-effects, such as feeling dizzy or faint.
Procure evitar substitutos de sal que contenham potássio. Isso porque os substitutos podem aumentar a quantidade de potássio no seu sangue, o que pode causar problemas.
If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking losartan. This is because your blood pressure may drop too low if you are given some anaesthetics.
Treatment with losartan is usually long-term unless you experience an adverse effect. Continue to take the tablets regularly, unless you are advised otherwise by your doctor.
Continue lendo abaixo
Can losartan cause problems?
Voltar ao conteúdoAlong with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with losartan. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.
Common losartan side-effects (these affect fewer than 1 in 10 people) | O que posso fazer se passar por isso? |
Feeling tired, or dizzy and light-headed when you stand up (due to low blood pressure) | Levantar-se e se mover mais lentamente deve ajudar. Se começar a se sentir tonto, sente-se por alguns minutos antes de se levantar novamente |
Changes in the amount of potassium in your blood | You will have blood tests from time to time to check for this |
Se você também estiver tomando hidroclorotiazida em combinação com este medicamento:
Estudos sugerem que tomar doses mais altas de hidroclorotiazida por longos períodos de tempo pode aumentar o risco de certos tipos de câncer de pele.
Informe o seu médico se você já foi tratado para câncer de pele antes.
Informe seu médico sobre qualquer nova pinta ou alteração em pintas existentes, ou marcas preocupantes na sua pele.
Use protetor solar sob luz solar intensa. Não use camas de bronzeamento.
Se você sentir quaisquer outros sintomas que acha que podem ser devido ao medicamento, fale com seu médico ou farmacêutico para mais conselhos.
How to store losartan
Voltar ao conteúdoMantenha todos os medicamentos fora do alcance e da vista das crianças.
Store the tablets in a cool, dry place, away from direct heat and light.
Informações importantes sobre todos os medicamentos
Voltar ao conteúdoInformações importantes sobre todos os medicamentos
Nunca tome mais do que a dose prescrita. Se suspeitar que você ou outra pessoa possa ter tomado uma overdose deste medicamento, vá imediatamente ao departamento de emergência do hospital local. Leve o recipiente com você, mesmo que esteja vazio.
Este medicamento é para você. Nunca o dê a outras pessoas, mesmo que a condição delas pareça ser a mesma que a sua.
Não guarde medicamentos vencidos ou indesejados. Leve-os à sua farmácia local, que se encarregará de descartá-los para você.
Se você tiver alguma dúvida sobre este medicamento, pergunte ao seu farmacêutico.
Relatar efeitos colaterais de um medicamento ou vacina
Se você sentir efeitos colaterais, pode relatá-los online através do Yellow Card website.

Inseguro sobre misturar medicamentos?
Verifique possíveis interações entre medicamentos, suplementos e alimentos antes de tomá-los juntos.
Perguntas frequentes
How does losartan actually help my heart if it's not beating well?
Losartan works by blocking the effects of a substance in your body called angiotensin II. Angiotensin II narrows your blood vessels and also increases the amount of fluid in your blood by triggering the production of aldosterone. By preventing angiotensin II from acting, losartan reduces the effort your heart has to make, which helps if your heart isn't beating as effectively as it should.
Can I switch the time of day I take my losartan if my routine changes?
It is recommended to take losartan at the same time each day to help you remember to take it regularly. While for most people this is in the morning, the article doesn't specify if changing the time is problematic, but it does say if you forget a dose, take it as soon as you remember, unless it's nearly the next day. Consistency is the key.
Is it safe to use salt substitutes if I'm trying to reduce my salt intake while on losartan?
No, you should try to avoid salt substitutes that contain potassium. Losartan can affect the amount of potassium in your blood, and these substitutes would further increase potassium levels, which could lead to problems.
What should I do if I notice any new skin changes, especially if I'm taking the combination tablet?
If you are taking losartan in combination with hydrochlorothiazide, you should tell your doctor about any new or changed moles or worrying marks on your skin. Studies suggest that higher doses of hydrochlorothiazide over long periods may increase the risk of certain skin cancers. It's also important to use sunscreen in strong sunlight and avoid sunbeds.
How long will I need to take losartan?
Treatment with losartan is usually considered long-term. You should continue to take the tablets regularly unless your doctor advises you otherwise, for example, if you experience an adverse effect.
If I feel dizzy when I stand up after taking losartan, what should I do?
If you experience dizziness or light-headedness when you stand up, which can happen due to low blood pressure, try getting up and moving more slowly. If you start to feel dizzy, sit for a few minutes before you attempt to stand up again.
Leitura adicional e referências
- Manufacturer's PIL, Cozaar® 12.5 mg, 25 mg, 50 mg and 100 mg Film-Coated Tablets; Organon Pharma (UK) Limited, The electronic Medicines Compendium. Dated December 2022.
- Medicamentos Completo BNF 89ª Edição; Associação Médica Britânica e Sociedade Real de Farmácia da Grã-Bretanha, Londres.
Continue lendo abaixo
About the authorView full bio

Michael Stewart, MRPharmS
Gerente de Revisão de Folhetos de Medicamentos – Contratado, Farmacêutico
BPharm (Hons), MRPharmS
Michael é um farmacêutico comunitário atuando nas Midlands e em South Yorkshire, com mais de 20 anos de experiência em aconselhamento sobre medicamentos e condições médicas. Ele tem uma sólida formação em treinamento em saúde, tendo produzido e ministrado cursos de treinamento para equipes de farmácia e funcionários de ambientes de cuidados residenciais, incluindo enfermeiros. Ele também contribuiu para conselhos consultivos de farmácia para o manejo de condições de baixa gravidade na comunidade.
About the reviewer

Sid Dajani
Sultan Dajani qualified at the London School of Pharmacy in 1994 and became the youngest elected member of the Royal Pharmaceutical Society council since its founding in 1842.
Histórico do artigo
As informações nesta página são escritas e revisadas por clínicos qualificados.
Próxima revisão prevista: 2 Fev 2028
2 Fev 2025 | Última versão

Pergunte, compartilhe, conecte-se.
Navegue por discussões, faça perguntas e compartilhe experiências em centenas de tópicos de saúde.
Inscreva-se no boletim informativo do Patient
Sua dose semanal de conselhos de saúde claros e confiáveis - escritos para ajudá-lo a se sentir informado, confiante e no controle.
By subscribing you accept our Política de Privacidade. Você pode cancelar a inscrição a qualquer momento. Nunca vendemos seus dados.