ACE inhibitors — patient guide

This page covers all the medicines in the ACE inhibitor family. If your medicine’s name ends in -pril, this is your page.

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Find your medicine

Generic name	Common brand names	Strengths	How often
Perindopril (arginine)	Coversyl Arginine	2.5 / 5 / 10 mg	Once daily
Perindopril (erbumine)	Coversyl, generics	2 / 4 / 8 mg	Once daily
Ramipril	Tritace, Ramace, generics	1.25 / 2.5 / 5 / 10 mg	Once daily
Enalapril	Renitec, generics	5 / 10 / 20 mg	Once or twice daily
Lisinopril	Zestril, Prinivil, generics	5 / 10 / 20 mg	Once daily
Quinapril	Accupril, generics	5 / 10 / 20 mg	Once or twice daily
Fosinopril	Monopril, generics	10 / 20 mg	Once daily
Trandolapril	Gopten, Odrik	0.5 / 1 / 2 / 4 mg	Once daily
Captopril	Capoten, generics	12.5 / 25 / 50 mg	2–3 times daily

Perindopril note: Coversyl Arginine and ordinary Coversyl/generic perindopril are not the same numbers but are the same drug. 5 mg arginine = 4 mg erbumine. If your pharmacist swaps brands, the milligrams may change but the dose hasn’t. Ask if you’re unsure.

Closely related family — ARBs. Names end in -sartan (irbesartan, telmisartan, candesartan…). Same mechanism, almost no cough. Often used as a back-up if an ACE-I causes cough.

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What it treats

ACE inhibitors 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.
• After a heart attack — they protect the heart muscle from further damage.
• Kidney protection in diabetes — they slow kidney damage even if your BP is fine.

The mechanism is the same in all of these. The goal is different, and that matters: in heart failure, post-heart-attack, or diabetic kidney protection, we usually keep the medicine going even if BP is well-controlled, because the drug is doing more than lowering a number.

I’ll tell you which situation you’re in.

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The basics

1. Take it at the same time every day. Most ACE-Is are once daily; captopril is 2–3 times. 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 (less than 1 in 200) but serious. Stop the medicine on the way.
3. Don’t stop on your own. If something feels wrong, message me — we can almost always fix 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 standing up. Normal in the first week. Get up slowly. Drink enough water.
• You probably won’t “feel” anything different otherwise. BP medicines often don’t have a felt effect.
• A small number of people develop the cough this early.

Week 2

• Get the blood test I ordered.
• Light-headedness should be settling.
• If you have a home BP monitor, take a daily reading at the same time each day.

Weeks 3–4

• The medicine’s full BP effect kicks in.
• We’ll meet to review your readings and tests.

When will it start working?

The first dose starts lowering BP within hours, but the full effect builds over 2–4 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

ACE inhibitors 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 24–48 hours. If you’re not sure, message.

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Tap any section below to expand the detail.

How does it work?

ACE inhibitors block an enzyme called angiotensin-converting enzyme. That enzyme normally produces a hormone (angiotensin II) which tightens your blood vessels and tells the kidneys to hold onto salt and water. Blocking it relaxes the vessels, drops the BP, and reduces strain on the heart and kidneys.

The same effect lowers pressure inside the kidneys’ filtering units, which is why these drugs slow kidney damage in diabetes — they’re doing structural protection, not just BP control.

Side effects in detail

Common (usually mild)

• Dry, tickly cough. 10–20%. Can start anywhere from a few days to several months after starting. Doesn’t mean the medicine isn’t working. Best fix is swapping to an ARB.
• Light-headedness on standing, especially in the first 1–2 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 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 ~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.

Uncommon

• Metallic taste or reduced taste — often improves with time.
• Mild rash.

Rare but serious — go to ED

• Angioedema. Sudden swelling of face, lips, tongue, or throat. Affects roughly 1 in 200 to 1 in 1000 people per Makani et al. Am J Cardiol 2012 meta-analysis. The risk is higher in people of African descent. There’s also a rarer form that affects the bowel — unexplained severe abdominal pain on an ACE-I should be mentioned to us. 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 ACE-I, 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.
• Sacubitril/valsartan (Entresto) — used in heart failure. There must be a 36-hour gap when switching between this and an ACE-I, because combining them causes serious angioedema risk. Your cardiologist or I will manage the switch.
• Lithium — your ACE-I can raise lithium blood levels.
• Other BP medicines in the same family — ACE-Is aren’t usually combined with ARBs or with aliskiren.

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.

Generic substitution at the pharmacy. Generic versions are bioequivalent — they work the same. If the pharmacist offers a cheaper generic, that’s fine. The exception is the Coversyl Arginine vs Coversyl/generic perindopril issue mentioned at the top — the numbers look different but the dose is the same.

Monitoring — what blood tests and when

• Blood test 1–2 weeks after starting or after a dose change. Checks kidney function and potassium.
• BP check 2–4 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.
• Sick day rules (above) — a 24–48 hour pause during gastro or heat illness is reasonable.
• 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

ACE inhibitors are not safe in pregnancy, particularly after the first trimester. They can harm the baby’s kidneys and development.

• Planning a pregnancy: tell me before trying. We swap to a pregnancy-safe BP medicine first.
• Already on one 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. Some ACE-Is (enalapril, captopril) have the most safety data and are usually okay. We’ll choose case by case.

If you’re on a combination tablet

Many ACE-Is come pre-combined with a second drug. If your tablet name is one of these, you’re on more than just an ACE-I:

• Coversyl Plus = perindopril + indapamide (a “water tablet”)
• Coversyl Plus LD = lower-dose version of the above
• Coveram = perindopril + amlodipine (a calcium-channel blocker)
• Triplixam = perindopril + indapamide + amlodipine (three drugs)
• Tribenzor / Sevikar HCT — olmesartan combinations (these are ARBs, not ACE-Is)

Everything on this page applies to the ACE-I portion of your combination. The other drug has its own side effects and considerations — ask me, and I’ll get you the relevant page when it’s ready.

Cost

Most ACE inhibitors 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.

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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.

Two principles. First: ACE inhibitors work, and they’re well-evidenced. Lifestyle changes also work. Combined, they work better than either alone. Second: medicines aren’t always permanent. For BP, if you genuinely change your habits, your dose may come down or come off — but we do it 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 recommend them to any patient on an ACE-I for BP. Effect sizes are in mmHg systolic so you can see the magnitude — a small dose of medicine moves BP by ~5–10 mmHg, so several of these stacked together is genuinely equivalent.

• DASH-style eating pattern (NEJM 1997). Vegetables, fruit, whole grains, lean protein, low saturated fat, low added sodium. Expected effect: ~6–11 mmHg systolic.
• Sodium reduction below 2 g/day (~5 g salt). Read labels — most sodium is hidden in processed food, not the saltshaker. Effect: 5–6 mmHg, more if you’re salt-sensitive.
• Aerobic exercise. 150 minutes/week of brisk walking, cycling, swimming, or equivalent. Effect: 5–7 mmHg.
• Resistance training. 2–3 sessions/week. Adds another 2–4 mmHg on top of aerobic.
• Weight loss. Roughly 1 mmHg per kg lost, sustained.
• Reducing alcohol. Each standard drink per day above 1–2 adds 1–2 mmHg of BP. Cutting back: 3–4 mmHg of room to work with.
• Treating sleep apnoea if you have it. Effects vary but can be large. Snoring + daytime tiredness + 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 if there’s a specific reason.
• Stress reduction practices — meditation, slow breathing (~6 breaths/minute), yoga. ~2–5 mmHg over months of practice.
• Hibiscus tea, 2–3 cups daily. Several studies show ~3–7 mmHg systolic reduction. Roughly equivalent to a small dose of an ACE-I.
• Aged garlic (specifically aged, not raw culinary garlic). Some meta-analyses show 5–10 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). 4–5 mmHg.

Limited or emerging evidence

• Fish oil, high dose (3+ g EPA/DHA daily). 2–4 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 recommendations I’d make 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 ACE inhibitor

• Zinc. ACE inhibitors can increase the body’s excretion of zinc. Whether that matters clinically is debated. Symptoms worth mentioning to me: persistent taste changes, slow wound healing, frequent minor infections, brittle nails. If you have those, we can check a level. Don’t routinely supplement zinc without checking — too much zinc causes copper deficiency.
• 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 ACE-I they can push potassium too high. Check with me before using.
• Hydration. Stay genuinely hydrated. ACE-Is + dehydration is what makes you light-headed and stresses your kidneys.

Earning a lower dose

ACE inhibitors 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 ACE-I 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 — cough, dizziness on standing, taste changes — note when they started and how often.
• 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.