Lisinopril (Hydrochlorothiazide) – Patient Information for Australia
Basic Product Information
| International Nonproprietary Name (INN): | Lisinopril and Hydrochlorothiazide |
| Common Australian Brand Names: | Zestoretic®, Prinzide®, generic brands |
| ATC Code: | C09BA03 |
| Available Forms and Strengths: | Tablet – Lisinopril 10 mg/ Hydrochlorothiazide 12.5 mg; Lisinopril 20 mg/ Hydrochlorothiazide 12.5 mg; Lisinopril 20 mg/ Hydrochlorothiazide 25 mg |
| Manufacturers: | AstraZeneca Pty Ltd, Alphapharm Pty Ltd, authorized generic manufacturers |
| Prescription Status (Australia): | S4 – Prescription Only Medicine |
Mechanism of Action
In Simple Terms:Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor. It helps relax blood vessels and reduce blood pressure. Hydrochlorothiazide is a diuretic (“water tablet”) helping your kidneys remove extra salt and water from the body. Together, they lower blood pressure more effectively and reduce strain on the heart and blood vessels.
For Specialists:Lisinopril inhibits ACE, preventing the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. This reduces systemic vascular resistance and aldosterone secretion. Hydrochlorothiazide acts on the distal convoluted tubule to inhibit sodium reabsorption, leading to increased excretion of sodium and water, and a reduction in plasma volume, thus enhancing antihypertensive effects.
Pharmacokinetics
- Absorption: Lisinopril is slowly absorbed (about 25%, unaffected by food). Hydrochlorothiazide’s absorption is about 60–80%.
- Metabolism: Lisinopril is not metabolised; it is excreted unchanged by the kidneys. Hydrochlorothiazide is minimally metabolised and excreted through urine.
- Peak Plasma: Lisinopril: 6–8 hours; Hydrochlorothiazide: 1–5 hours.
- Elimination: Mainly renal (urine).
- Duration of Action: Antihypertensive effect lasts 24 hours for both components.
Use in Everyday Life & Best Practices
In the Australian context, Lisinopril (Hydrochlorothiazide) is commonly prescribed for high blood pressure which helps to prevent strokes, heart attacks, and kidney problems. Your doctor might also prescribe it for heart failure.
- Typical starting dose: 10 mg/12.5 mg once daily, increased by your doctor depending on your response.
- Always take the medication exactly as prescribed and do not stop suddenly unless advised by your doctor.
- Regular monitoring of blood pressure and kidney function is recommended in Australia, usually managed by your local GP or a nurse practitioner.
- Report symptoms like dizziness, cough, excessive urination, or muscle cramps to your healthcare provider.
Dosing in the Morning vs Evening
- Lisinopril/Hydrochlorothiazide is generally taken in the morning to coincide with natural blood pressure rhythms and to avoid sleep disruption due to increased urination.
- Dosing in the evening may increase the need to urinate overnight (“nocturia”), leading to disturbed sleep, which is common in Australian patients reporting to pharmacists.
- Choose a regular time each day, and set a daily reminder if needed for consistency.
Taking With Food or on an Empty Stomach
This medicine can be taken with or without food. Food does not significantly affect absorption of either component. For many Australians, a routine such as taking it after breakfast is recommended for convenience and consistency, particularly for those following an English diet rich in breakfast cereals and fruit.
Interaction Warnings
| Food/Drink/Medication | Interaction/Advice |
|---|---|
| Alcohol | Increases risk of low blood pressure/dizziness. Limit intake. |
| Potassium supplements, salt substitutes | May increase potassium levels. Check with your doctor before using. |
| NSAIDs (e.g. ibuprofen, naproxen) | May reduce effect and increase risk of kidney damage. |
| Other antihypertensives | May increase blood pressure-lowering effect; monitor closely. |
| Diabetes medicines (insulin, metformin) | Monitor for low blood sugar – ACE inhibitors can increase insulin sensitivity. |
| Lithium | Toxicity risk increased. Usually avoided. |
| Anti-gout medicines (allopurinol) | Potential interaction; consult with your doctor. |
Indications
| Indication | Status (Australia) | Notes |
|---|---|---|
| Essential hypertension | Approved | First or second-line therapy |
| Heart failure (with reduced ejection fraction) | Off-label | When appropriate as per specialist recommendation |
| Post-myocardial infarction | Off-label | Specialist directed |
Dosing According to Clinical Indications
| Patient Group | Usual Dose | Maximum Dose | Notes |
|---|---|---|---|
| Adults (hypertension) | 10/12.5 mg once daily | 20/25 mg once daily | Adjust as required, titrate every 2–4 weeks |
| Elderly (over 65 years) | Start at lower dose if possible | As above | Monitor for dehydration & kidney function closely |
| Children & Adolescents | Not recommended | – | Safety/efficacy not established |
| Renal impairment | Avoid if severe (creatinine clearance <30 mL/min) | – | Consult specialist |
Safety Profile & Side Effects
- Common: Dizziness, headache, tiredness, dry cough, increased urination, muscle cramps, stomach upset.
- Occasional: Rash, changes in kidney function, elevated blood potassium, low blood sodium, lightheadedness on standing.
- Rare but Serious: Swelling of face/lips/tongue (angioedema), severe allergic reactions, jaundice, irregular heartbeat.
Australian regulatory authorities (Therapeutic Goods Administration, TGA) recommend immediate medical help if you experience swelling of the tongue or face, severe rash, or difficulty breathing.
Guidelines for Proper Use
- Have your blood pressure and kidney function tested regularly as advised by your GP or pharmacist.
- Aim to take the medication at the same time each day for best control.
- Unless instructed otherwise, drink normal amounts of water; avoid dehydration or excessive salt intake.
- Be cautious in hot weather, during illnesses causing vomiting/diarrhoea, or when fasting (as may occur in certain Australian religious or cultural settings), as the risk of dehydration is increased.
- If you miss a dose, take it as soon as you remember unless it’s almost time for the next dose. Do not double up.
Alternative Treatment Options
- Other ACE inhibitor combinations (e.g. perindopril/indapamide, ramipril/hydrochlorothiazide): Similar efficacy and reimbursed on the Pharmaceutical Benefits Scheme (PBS).
- ARB (Angiotensin receptor blocker) combinations (e.g. irbesartan/hydrochlorothiazide): Suitable for patients intolerant to ACE inhibitors. Less cough; comparable blood pressure control.
- Calcium channel blockers (e.g. amlodipine): Also first-line; no effect on potassium or renal function but may cause swelling of ankles.
- Beta-blockers (e.g. metoprolol): Used when indicated for heart disease; less effective for hypertension alone.
Legal, Registration, and Reimbursement Status in Australia
- Registration: Registered with the TGA for treatment of hypertension.
- Prescription Requirements: S4 medication—prescription required from a medical or nurse practitioner.
- Availability: Listed on the PBS (Pharmaceutical Benefits Scheme) for eligible patients, allowing subsidised access across Australia.
- Recalls & Warnings: Monitor TGA Consumer Medicines Information (CMI) for updates.
Latest Research & Clinical Guidance (2022–2025)
- Current local guidance (Australian Therapeutic Guidelines: Cardiovascular, 2023 update) continues to recommend ACE inhibitor/thiazide combinations as standard first- and second-line antihypertensive therapy, especially for adults failing monotherapy (Therapeutic Guidelines, 2023).
- Randomised controlled data (Gupta et al., Lancet 2023) suggests combination therapy at low doses improves adherence and reduces cardiovascular risk compared to monotherapy escalation.
- Special consideration: Elderly and chronic kidney disease patients should be monitored closely per recent European and Australian guideline consensus (Williams et al., Hypertension 2023; National Heart Foundation of Australia, 2022).
Availability and Delivery
| Pack Size | Tablets per Pack | Indicative Price (PBS subsidised) | Private Price Range |
|---|---|---|---|
| 30 | 30 | AUD $6.70 (concession) | AUD $10–$19 |
| 60 | 60 | AUD $13.40 (concession) | AUD $18–$32 |
| City | Pharmacy Pickup | Express Delivery |
|---|---|---|
| Sydney | Same day | 1 business day |
| Melbourne | Same day | 1 business day |
| Brisbane | Same day | 1–2 business days |
| Perth | 1 business day | 2 business days |
| Hobart | 1 business day | 2 business days |
| Darwin | 1–2 business days | 2–3 business days |
Frequently Asked Questions (FAQ)
- Q: Can I drink alcohol while taking Lisinopril (Hydrochlorothiazide)?
A: Small amounts may be tolerated but alcohol can increase the risk of side effects such as dizziness. Ask your doctor or pharmacist for individual advice. - Q: Do I need regular blood tests?
A: Yes. Blood tests to check kidney function and electrolyte levels are recommended before starting and periodically during treatment. - Q: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember unless it is almost time for your next scheduled dose. Do not take a double dose. - Q: Can I take this medicine if I am pregnant or planning pregnancy?
A: No. Neither Lisinopril nor Hydrochlorothiazide should be taken during pregnancy. Consult your doctor for safer alternatives. - Q: Are there any special precautions for use in summer or during heatwaves in Australia?
A: Yes. This medicine can increase the risk of dehydration. Drink plenty of fluids, avoid excessive heat, and watch out for symptoms like dizziness, fainting, or confusion.
