ARBs — patient guide

This page covers all the medicines in the ARB (angiotensin II receptor blocker) family. If your medicine’s generic name ends in -sartan, this is your page.

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Find your medicine

Generic name	Common brand names	Strengths	How often
Candesartan	Atacand, Atacand Plus (combo), generics	4 / 8 / 16 / 32 mg	Once daily
Irbesartan	Avapro, Karvea, Karvezide (combo), Coaprovel (combo), generics	75 / 150 / 300 mg	Once daily
Losartan	Cozaar, Hyzaar (combo), generics	25 / 50 / 100 mg	Once daily
Olmesartan	Olmetec, Olmetec Plus (combo), Sevikar (combo), Sevikar HCT (combo), generics	10 / 20 / 40 mg	Once daily
Telmisartan	Micardis, Micardis Plus (combo), Twynsta (combo), generics	40 / 80 mg	Once daily
Valsartan	Diovan, Diovan HCT (combo), Exforge (combo), Exforge HCT (combo), Entresto (combo), generics	40 / 80 / 160 / 320 mg	Once daily
Eprosartan	Teveten	600 mg	Once daily

Generic substitution at the pharmacy. Generics are bioequivalent to the branded versions and work the same. If the pharmacist offers a cheaper generic, that’s fine. Ask if anything looks different on the box and you’re unsure.

Closely related family — ACE inhibitors. Names end in -pril (perindopril, ramipril, lisinopril, etc.). Same renin-angiotensin system, one step earlier in the chemistry. ARBs are commonly chosen when an ACE-I has caused a dry cough — same blood-pressure work, very low cough rate.

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What it treats

ARBs are prescribed for more than just blood pressure. Your reason may be one or more of:

• High blood pressure — the most common reason.
• Heart failure — they help the heart pump more effectively and reduce hospitalisations. Strongest ARB evidence in this setting comes from candesartan (CHARM programme, Lancet 2003).
• After a heart attack — valsartan has the post-MI evidence (VALIANT, NEJM 2003).
• Kidney protection in type 2 diabetes with protein leak (albuminuria) — irbesartan has the strongest evidence (IDNT, NEJM 2001; IRMA-2, NEJM 2001).
• Alternative when an ACE inhibitor causes cough — the most common reason patients are switched into the ARB class.

The mechanism is the same across all these reasons. The goal differs — and that matters: in heart failure, after a heart attack, or in diabetic kidney protection, we usually keep the medicine going even when blood pressure is well controlled, because the drug is doing more than lowering a number.

I’ll tell you which reason applies to you.

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The basics

1. Take it at the same time every day. All ARBs in this list are once daily. Miss a dose? Take the next one — don’t double up.
2. Go to ED if your lips, tongue, throat, or face suddenly swell. Rare on an ARB but not zero. Stop the medicine on the way.
3. Don’t stop on your own. If something feels wrong, message me — we can almost always sort the problem without stopping the medicine.

Everything else — side effects, the blood test you’ll need, the integrative angle — is below.

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What to expect in the first month

Week 1

• You may feel light-headed, especially when you stand up. Normal early on. Stand slowly. Drink enough water.
• You probably won’t feel anything different otherwise. ARBs (like most BP medicines) often don’t have a felt effect.

Week 2

• Get the blood test I ordered (kidney function and potassium).
• Light-headedness should be settling.
• If you have a home BP monitor, take a daily reading at the same time of day.

Weeks 3–4

• The full BP effect builds in.
• We’ll meet to review your readings and the blood test.

When will it start working?

The first dose starts lowering BP within hours, but the full effect builds over 2 to 4 weeks. Don’t be alarmed if home readings don’t drop overnight. We’re aiming for a steady, gentle reduction — not a sudden one. Sudden drops cause the light-headedness; slow ones don’t.

Sick day rules — when to pause

If you have any of these for more than a few hours, pause the medicine and message us:

• Vomiting
• Severe diarrhoea
• Fever where you can’t keep fluids down
• Heavy sweating or heat illness with poor fluid intake

ARBs rely on your body being well-hydrated. When you’re dry, they can stress the kidneys. Restart once you’re eating, drinking, and feeling better — usually 24 to 48 hours. If you’re not sure, message.

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Tap any section below to expand the detail.

How does it work?

ARBs block the receptor that the hormone angiotensin II binds to (the AT1 receptor). Angiotensin II normally tightens your blood vessels and tells the kidneys to hold onto salt and water. Block its receptor and the vessels relax, the BP drops, and the heart and kidneys do less mechanical work.

ACE inhibitors act one step earlier in the same system — they block the enzyme that makes angiotensin II. ARBs let the enzyme do its job but stop the hormone from doing its job at the receiver end. Same downstream effect on BP. The reason ARBs don’t cause the dry cough is that the ACE enzyme also breaks down a substance called bradykinin in the airways — when you block ACE, bradykinin builds up and tickles the cough reflex in some people. ARBs leave that part alone.

The lowering of pressure inside the kidneys’ filtering units is why ARBs slow kidney damage in diabetes — they’re doing structural protection, not just BP control.

Side effects in detail

Common (usually mild)

• Light-headedness on standing, especially in the first 1 to 2 weeks. Stand up slowly. Stay hydrated.
• Higher potassium on blood tests. Usually mild in healthy kidneys. Higher risk if you have chronic kidney disease, take a potassium-sparing diuretic (spironolactone, eplerenone, amiloride), use potassium-based salt substitutes, or take potassium supplements.
• Small rise in creatinine (a kidney function blood test). A modest rise after starting is expected and reflects how the drug works. A rise of more than around 30% from baseline may mean we need to reduce the dose, stop, or investigate. I watch these numbers — you don’t need to.
• Headache or fatigue in the first weeks, usually settling.
• Dry cough — uncommon on an ARB. If you’re getting one, it’s more likely to be something else (post-viral, reflux, asthma) — tell me and we’ll sort it out.

Uncommon

• Mild rash.
• Slight rise in liver enzymes (relevant mostly for valsartan and irbesartan in people with existing liver impairment).

Olmesartan-specific — uncommon but worth knowing

• Sprue-like enteropathy. A coeliac-disease-like bowel reaction — chronic diarrhoea, weight loss, sometimes villous atrophy on a biopsy. Months to years after starting. Reversible on stopping olmesartan. First described by Rubio-Tapia et al. (Mayo Clin Proc 2012). If you’re on olmesartan and have unexplained chronic diarrhoea, mention it.

Bilateral renal artery stenosis — important contraindication

• ARBs reduce pressure inside the kidney’s filtering units. That’s protective in most settings. In bilateral renal artery stenosis (narrowing of both kidney arteries) the kidneys are already under-perfused, and adding an ARB can precipitate acute kidney injury. The frontmatter lists this in the class-specific contraindications. If you have known renal artery disease, vascular imaging history, or your creatinine rises sharply after starting, message us — we will investigate.

Rare but serious — go to ED

• Angioedema. Sudden swelling of the face, lips, tongue, or throat. Less common with ARBs than ACE inhibitors but documented — the Makani et al. Am J Cardiol 2012 meta-analysis puts the absolute risk lower than ACE inhibitors but not zero. If you’ve had angioedema on an ACE-I previously, there’s roughly a 2 to 10% chance of it recurring on an ARB; we’ll discuss whether it’s still worth trying. Stop the medicine and get to ED.
• Severe dizziness or fainting.
• Sharp drop in urine output, or new significant swelling of ankles or face.

Drugs, food, and alcohol

Tell me or your pharmacist before combining with:

• Anti-inflammatories (ibuprofen/Nurofen, diclofenac/Voltaren, naproxen, celecoxib). Combined with an ARB they can stress the kidneys — especially if you’re also on a diuretic (“triple whammy”). Occasional use is usually fine; regular use needs a conversation. Paracetamol is fine.
• Potassium supplements, salt substitutes (LoSalt, NoSalt, many “low-sodium” salts — most are potassium chloride), and potassium-sparing diuretics (spironolactone/Aldactone, eplerenone, amiloride). All can push potassium too high in combination with an ARB.
• An ACE inhibitor. Combining an ARB with an ACE inhibitor causes more harm than benefit — the ONTARGET trial (NEJM 2008) settled this. We switch, we don’t combine.
• Aliskiren (a direct renin inhibitor) — avoid the combination if you have diabetes or an eGFR under 60.
• Sacubitril/valsartan (Entresto). If you switch between Entresto and an ACE inhibitor, there must be a 36-hour gap because combining them causes serious angioedema risk. Switching between Entresto and another ARB doesn’t need a washout (Entresto already contains valsartan). Your cardiology team will manage the switch.
• Lithium — ARBs can raise lithium blood levels. Your level will be checked more often if both are on board.
• Trimethoprim (alone or as Bactrim) — short courses are usually safe with monitoring; the additive risk is hyperkalaemia, particularly in older adults or chronic kidney disease.

Food. No specific food restrictions. Don’t ultra-restrict salt unless we’ve planned it — you can drop BP too far.

Alcohol. Light to moderate amounts are okay. Heavy drinking makes BP control unpredictable and worsens light-headedness.

Monitoring — what blood tests and when

• Blood test 1 to 2 weeks after starting or after a dose change. Checks kidney function and potassium.
• BP check 2 to 4 weeks after starting.
• Then annually with your routine review, unless something changes.
• Message us if you: start a new medicine (including over-the-counter or supplements), get a gastro illness, start a new diet, or feel persistently dizzy.

Stopping or pausing

Don’t stop without talking to me first.

• If side effects are the problem, we usually swap medicines rather than stop. There are good alternatives — and within the ARB class, swapping between agents is reasonable if one isn’t suiting you.
• Sick day rules (above) — a 24 to 48 hour pause during gastro or heat illness is reasonable and part of normal use.
• Before surgery, your anaesthetist may or may not ask you to hold a dose. Follow their instructions.
• Stopping cold turkey can let BP rebound, and if the medicine is protecting your heart or kidneys you lose that protection regardless of what your BP looks like.

Pregnancy and breastfeeding

ARBs are not safe in pregnancy, particularly after the first trimester. They can harm the baby’s kidneys, reduce the amniotic fluid, and affect skull and lung development.

• Planning a pregnancy: tell me before trying. We swap to a pregnancy-safe BP medicine first — usually labetalol, methyldopa, or nifedipine, depending on the situation.
• Already on an ARB and just found out you’re pregnant: contact me as soon as possible. Don’t panic, but don’t take the next dose until we’ve talked.

Breastfeeding. ARBs are generally avoided during breastfeeding — there’s less safety data than for some older BP medicines. We’ll usually switch to a lactation-safe alternative.

If you’re on a combination tablet

Many ARBs come pre-combined with a second drug — a water tablet (thiazide), a calcium-channel blocker, or both. If your tablet name is one of these, you’re on more than just an ARB:

• Atacand Plus = candesartan + hydrochlorothiazide (water tablet)
• Karvezide / Coaprovel = irbesartan + hydrochlorothiazide
• Hyzaar = losartan + hydrochlorothiazide
• Olmetec Plus = olmesartan + hydrochlorothiazide
• Sevikar = olmesartan + amlodipine (a calcium-channel blocker)
• Sevikar HCT = olmesartan + amlodipine + hydrochlorothiazide (three drugs)
• Micardis Plus = telmisartan + hydrochlorothiazide
• Twynsta = telmisartan + amlodipine
• Diovan HCT = valsartan + hydrochlorothiazide
• Exforge = valsartan + amlodipine
• Exforge HCT = valsartan + amlodipine + hydrochlorothiazide
• Entresto = sacubitril + valsartan (heart failure, started by cardiology)

Everything on this page applies to the ARB portion of your combination tablet. The other drug has its own side effects and considerations — for example, hydrochlorothiazide can lower potassium and magnesium (the opposite direction to the ARB), and amlodipine can cause ankle swelling. Ask me, and I’ll get you the relevant page when it’s ready.

Special note on Entresto. Mandatory 36-hour gap when switching to or from an ACE inhibitor — combining them causes serious angioedema risk. Switching between Entresto and another ARB doesn’t need a washout.

Off-label corner — losartan and gout

Losartan has a mild uric-acid-lowering effect — modest, but real. This isn’t a TGA-approved use, and losartan is not a substitute for proper urate-lowering medicines (allopurinol, febuxostat) if you have established gout. But if you need a BP medicine and you happen to have gout or borderline-high uric acid, choosing losartan rather than a different ARB is sometimes worth the small extra nudge. The evidence is summarised in BMJ Best Practice.

This is a choice, not an imperative. If we go with losartan for this reason, we’ll discuss the trade-off — losartan has the shortest half-life in the class, so dosing timing matters slightly more.

Cost

All ARBs in this list are on the PBS. From 1 January 2026, the PBS co-payment is:

• General patient: up to $25.00 per script
• Concession card holder: up to $7.70 per script

Generic versions cost the same as branded ones at PBS pricing and work the same. Your actual charge may be lower if your medicine costs less than the co-payment (under-co-payment medicines), or higher if you choose a brand with a price premium. Confirm with your pharmacist — they can show you the exact price for your script and tell you the cheapest option in stock. Eprosartan (Teveten) supply has been intermittent in Australia; if it’s not available, we’ll swap to another ARB on the PBS.

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The integrative view

Most of the patients I see want to do everything they reasonably can in addition to taking the medicine. This section is the longer version of that conversation. It overlaps substantially with what I’d say on an ACE inhibitor — the BP-lowering lifestyle levers are the same regardless of which renin-angiotensin medicine you’re on. The differences specific to being on an ARB are in the last block.

Two principles. First: ARBs work, and the evidence is solid. Lifestyle changes also work. Combined, they work better than either alone. Second: medicines aren’t always permanent. If you genuinely change your eating, movement, weight, and alcohol, your dose may come down — sometimes off entirely for BP-only patients. We do that together, with monitoring, not on your own.

Strong evidence — these reliably lower BP

These are interventions where the data is solid enough that I’d suggest them to any patient on an ARB for blood pressure. Effect sizes are in mmHg systolic so you can see the magnitude — a small dose of medicine moves BP by around 5 to 10 mmHg, so stacking several of these is genuinely equivalent.

• DASH-style eating pattern (NEJM 1997). Vegetables, fruit, whole grains, lean protein, low saturated fat, low added sodium. Expected effect: around 6 to 11 mmHg systolic.
• Sodium reduction below 2 g/day (about 5 g salt). Read labels — most sodium hides in processed food, not the saltshaker. Effect: 5 to 6 mmHg, more if you’re salt-sensitive.
• Aerobic exercise. 150 minutes per week of brisk walking, cycling, swimming, or equivalent. Effect: 5 to 7 mmHg.
• Resistance training. 2 to 3 sessions per week. Adds another 2 to 4 mmHg on top of aerobic.
• Weight loss. Roughly 1 mmHg per kilogram lost, sustained.
• Reducing alcohol. Each standard drink per day above 1 to 2 adds 1 to 2 mmHg of BP. Cutting back: 3 to 4 mmHg of room to work with.
• Treating sleep apnoea if you have it. Effects vary but can be large. Snoring plus daytime tiredness plus observed pauses in breathing — worth a sleep study.

Moderate evidence — likely helpful

• Magnesium-rich foods (leafy greens, nuts, seeds, legumes, dark chocolate). Real BP benefit, particularly if intake has been low. Food first; supplements only when there’s a specific reason — for example, if you’re on a combination tablet with hydrochlorothiazide, which lowers magnesium.
• Stress reduction practices — meditation, slow breathing (around 6 breaths per minute), yoga. About 2 to 5 mmHg over months of practice.
• Hibiscus tea, 2 to 3 cups daily. Several studies show around 3 to 7 mmHg systolic reduction. Roughly equivalent to a small dose of an ARB.
• Aged garlic (specifically aged, not raw culinary garlic). Some meta-analyses show 5 to 10 mmHg systolic reduction. Talk to me before starting if you’re on blood thinners — garlic supplements can affect bleeding.
• Dietary nitrate — beetroot juice, leafy greens (spinach, rocket). 4 to 5 mmHg.

Limited or emerging evidence

• Fish oil, high dose (3+ g EPA/DHA daily). 2 to 4 mmHg. The bigger reason to take it is cardiovascular protection more broadly.
• CoQ10 — mixed evidence for BP itself. More relevant if you’re also on a statin.
• L-theanine, ashwagandha, hawthorn — weak evidence. Not interventions I’d recommend on the data alone, but I won’t talk you out of them if they’re already part of your routine.

Specific to being on an ARB

• Potassium. A normal-potassium diet (including bananas, avocados, tomatoes, potatoes) is fine and good for you. The thing to avoid is potassium-based salt substitutes like LoSalt or NoSalt — combined with an ARB they can push potassium too high. Same precaution as ACE inhibitors. Check with me before using.
• Zinc. The evidence that ARBs cause clinically meaningful zinc loss is weaker than the equivalent ACE-inhibitor evidence. Symptoms worth mentioning to me: persistent taste changes, slow wound healing, frequent minor infections, brittle nails. If those appear, we can check a level. Don’t routinely supplement zinc without checking — too much zinc causes copper deficiency.
• Hydration. Stay genuinely hydrated. ARBs plus dehydration is the combination that makes you light-headed and stresses your kidneys.
• Combination-tablet considerations. If you’re on an ARB-with-hydrochlorothiazide combination (Atacand Plus, Karvezide, Hyzaar, Olmetec Plus, Micardis Plus, Diovan HCT, etc.), the thiazide is doing its own thing — lowering magnesium and potassium and modestly raising uric acid. That changes the picture: leafy-green magnesium becomes more relevant, the no-potassium-salt-substitute rule still applies (ARB direction dominates), and if you have a gout tendency we’ll watch for flares.

Earning a lower dose

ARBs aren’t permanent for everyone. If you genuinely change your eating, movement, weight, and alcohol intake, your BP may drop enough that we can reduce the dose — sometimes off entirely. This is a goal worth aiming for.

Two caveats:

• We do this together, with regular home BP monitoring. Not on your own.
• If you’re on the ARB for heart failure, after a heart attack, or for diabetic kidney protection, we usually keep it going regardless of BP, because the drug is doing more than treating a number. I’ll tell you which group you’re in.

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Track these between now and your next visit

• Home BP readings — daily for the first 2 weeks, then a couple of times a week. Same time of day.
• Any new symptoms — dizziness on standing, headache, taste changes, swelling, or (if you’re on olmesartan) any new pattern of loose bowels.
• Anything new you’ve bought over the counter (painkillers, supplements, salt substitutes).

Bring the list to your review appointment.

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This is general information, not personal medical advice. Every patient is different. Decisions about your medicines — which one, what dose, when to stop, what to combine with — are made with the doctor who prescribed them. If anything on this page appears to contradict advice from your treating doctor, follow your doctor; they have context about your situation that this page cannot.

Reading this page does not establish a doctor-patient relationship with Dr Hoebing Lo. If you are not a current patient, please discuss your medicines with your own GP, specialist, or pharmacist.

About the integrative content. The lifestyle, dietary, and complementary recommendations on this page summarise current published research. Effect sizes are approximations from clinical studies — your individual response will vary, and real-world results are commonly smaller than trial results because day-to-day life differs from study conditions. Supplements and herbal products are not interchangeable with prescribed medication and can interact with it. Talk to your doctor and pharmacist before starting any new supplement, herbal product, or significant change in diet.

Currency. This page reflects clinical practice as of the last-reviewed date. Medicine evolves; specific details may date between reviews. Pricing shown is indicative; confirm with your pharmacist.

No commercial relationships. Dr Hoebing Lo has no financial or commercial relationship with the manufacturer of any medicine, brand, or supplement mentioned on this page.

Emergencies. If you have sudden swelling of face, lips, tongue, or throat; difficulty breathing; chest pain; or severe dizziness or fainting, call 000 or go to your nearest emergency department. Do not wait, and do not message us first.