Olmetec Plus

When a single blood pressure medicine is not sufficient to achieve adequate blood pressure control, a combination therapy approach in a single tablet can simplify treatment and support better adherence. Olmetec Plus tablets are a branded prescription combination medicine containing olmesartan medoxomil, an ARB, and hydrochlorothiazide, a thiazide diuretic. Together they lower blood pressure through two complementary mechanisms. A prescription can only be issued following a clinical consultation.

Olmetec Plus is a branded combination prescription medicine manufactured by Daiichi Sankyo. Each tablet contains two active ingredients: olmesartan medoxomil (an angiotensin receptor blocker, or ARB) and hydrochlorothiazide (a thiazide diuretic). This ARB and diuretic combination provides blood pressure control through two different but complementary pathways.

Olmetec Plus is licensed in the UK for the treatment of essential hypertension in adults. It is indicated for patients whose blood pressure is not adequately controlled on olmesartan alone, and as a substitute therapy for patients already taking both components as separate medicines. Three tablet strengths are available, each identified by the doses of olmesartan medoxomil and hydrochlorothiazide it contains. Olmetec Plus is a fixed dose combination and the two components cannot be adjusted independently.

As with Olmetec tablets (the olmesartan-only product), patients taking Olmetec Plus should be aware that olmesartan has been specifically associated with a rare but serious intestinal condition called sprue-like enteropathy. This is covered in detail in the side effects section below. If you develop persistent severe diarrhoea with significant weight loss during treatment, contact your prescriber promptly.

Olmetec Plus lowers blood pressure through the combined actions of its two active ingredients, each working through a different mechanism.

Olmesartan Medoxomil: AT1 Receptor Blockade

Olmesartan medoxomil is a prodrug that is converted in the body to olmesartan, the active form. Olmesartan blocks the AT1 receptor, through which the hormone angiotensin II raises blood pressure by causing blood vessels to narrow and the body to retain sodium and water. By blocking this receptor, olmesartan prevents these effects. Blood vessels remain relaxed and widened, and blood pressure falls. Olmesartan has a long duration of action that supports consistent blood pressure control over 24 hours from a single daily dose.

Hydrochlorothiazide: Thiazide Diuretic

Hydrochlorothiazide acts on the distal convoluted tubule of the kidney, where it reduces the reabsorption of sodium and chloride. This leads to increased urine production and a reduction in the overall volume of fluid circulating in the blood vessels. Lower circulating volume reduces the pressure the heart pumps against, providing a blood pressure lowering effect that is complementary to that of olmesartan.

The combination of AT1 receptor blockade and thiazide diuresis provides additive blood pressure reduction compared to either component taken alone. Delivering both components in a single tablet reduces the number of tablets a patient needs to take each day, which can support adherence to long-term cardiovascular therapy.

Always take Olmetec Plus exactly as your prescriber instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before starting treatment.

• Take one tablet once daily, at approximately the same time each day.
• Olmetec Plus can be taken with or without food.
• Swallow the tablet whole with a glass of water. Do not crush or chew the tablet.
• If you miss a dose, take it as soon as you remember on the same day. If you only remember the following day, skip the missed dose and continue with your normal schedule. Do not take two doses on the same day.
• Do not stop taking Olmetec Plus without speaking to your prescriber first. Blood pressure requires ongoing management and stopping suddenly can cause it to rise again.
• Olmetec Plus contains hydrochlorothiazide, a diuretic that increases urine production. This effect is most noticeable in the first few hours after taking each dose. Taking the tablet in the morning helps ensure this effect occurs during the day rather than disrupting sleep at night. Your prescriber may arrange periodic blood tests to check kidney function, potassium, and sodium levels during treatment. Attend all follow up appointments so your blood pressure and blood chemistry can be safely reviewed.

Olmetec Plus is available in three strengths. The appropriate strength is determined by your prescriber based on your blood pressure, your current or previous treatment with olmesartan alone, and your individual clinical response.

Olmetec Plus 20 mg/12.5 mg Tablets

Each tablet contains olmesartan medoxomil 20 mg and hydrochlorothiazide 12.5 mg. This is typically the first Olmetec Plus strength used in patients stepping up from Olmetec 20 mg alone when further blood pressure reduction is needed. It combines the standard ARB dose with a lower diuretic contribution, allowing a cautious increase in antihypertensive therapy.

Olmetec Plus 20 mg/25 mg Tablets

Each tablet contains olmesartan medoxomil 20 mg and hydrochlorothiazide 25 mg. This strength provides the same olmesartan dose as the 20 mg/12.5 mg tablet but with a higher diuretic dose. It is used when the 20 mg/12.5 mg strength has not achieved adequate blood pressure control, and where increasing the diuretic component is the preferred next step rather than increasing the olmesartan dose.

Olmetec Plus 40 mg/12.5 mg Tablets

Each tablet contains olmesartan medoxomil 40 mg and hydrochlorothiazide 12.5 mg. This strength provides the maximum olmesartan dose combined with the lower diuretic dose. It is used in patients who have been on Olmetec 40 mg alone and require the addition of a diuretic component for further blood pressure reduction. All dose adjustments are made by your prescriber. Do not change your strength without medical advice.

The maximum daily dose of olmesartan in Olmetec Plus is 40 mg and the maximum hydrochlorothiazide is 25 mg. Do not take more than one Olmetec Plus tablet per day. If blood pressure remains inadequately controlled, your prescriber may consider adding a third antihypertensive agent such as a calcium channel blocker rather than exceeding these doses.

Olmetec Plus can cause side effects from either of its active components. The information below is based on the current UK SmPC and MHRA guidance. Refer to the Patient Information Leaflet for the full list.

Common Side Effects (may affect up to 1 in 10 people)

• Dizziness, particularly on standing up quickly. The diuretic component can reduce circulating volume, increasing this risk.
• Low potassium levels (hypokalaemia) from the hydrochlorothiazide component. Symptoms include muscle cramps, weakness, and palpitations. Regular blood tests help to detect and manage this.
• Raised blood uric acid levels, which may trigger gout in susceptible patients
• Raised blood glucose levels, which may be relevant for patients with or at risk of diabetes

Uncommon Side Effects (may affect up to 1 in 100 people)

• Low sodium levels (hyponatraemia), which can cause fatigue, confusion, and headache
• Raised blood potassium levels (hyperkalaemia) from the olmesartan component, particularly in patients with kidney disease
• Increased frequency of passing urine, particularly in the first hours after each dose
• Nausea or abdominal discomfort
• Skin reactions including rash or sensitivity to sunlight

Important: Olmesartan and Sprue-Like Enteropathy

Olmesartan has been associated with a rare but serious intestinal condition known as sprue-like enteropathy. This applies to all olmesartan-containing medicines including Olmetec Plus. The condition causes severe, persistent diarrhoea with significant weight loss and can develop months or years after starting treatment. The MHRA issued a Drug Safety Update in 2013 highlighting this risk.

If you develop persistent severe diarrhoea combined with significant weight loss while taking Olmetec Plus, contact your prescriber promptly so that the cause can be investigated. Do not stop your blood pressure medicine without first seeking medical advice. If olmesartan-related enteropathy is confirmed, stopping the medicine typically leads to improvement.

Serious Side Effects: Seek Urgent Medical Attention

Go to your nearest accident and emergency department or call 999 immediately if you experience:

• Angioedema: sudden swelling of the face, lips, tongue, or throat. This is rare but potentially life threatening. Seek emergency help immediately.
• Signs of severe dehydration such as extreme thirst, very dark urine, confusion, or fainting, which may indicate excessive diuretic effect
• Signs of severe electrolyte disturbance such as muscle weakness, confusion, or an irregular heartbeat

Report any suspected side effect to your prescriber, pharmacist, or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Olmetec Plus May Be Suitable If You:

• Are an adult aged 18 or over with a confirmed diagnosis of essential hypertension
• Are already taking olmesartan alone (Olmetec) and your blood pressure needs further reduction with the addition of a diuretic
• Are already taking olmesartan and hydrochlorothiazide as separate medicines and wish to simplify to a single combination tablet
• Are already prescribed Olmetec Plus and require a repeat prescription through an online prescribing service

Olmetec Plus Is Not Suitable If You:

• Are pregnant or planning to become pregnant. Olmesartan is contraindicated in pregnancy. ARBs cause serious harm to the developing baby, particularly in the second and third trimesters, including kidney damage and foetal death. Contact your prescriber immediately if you become pregnant while taking Olmetec Plus.
• Are breastfeeding
• Have severe kidney impairment or are on dialysis
• Have severe liver disease or biliary obstruction
• Have low potassium or low sodium levels that have not been corrected
• Have diabetes or moderate to severe kidney impairment and are also taking aliskiren
• Have a known allergy or hypersensitivity to olmesartan medoxomil, hydrochlorothiazide, sulfonamide-derived medicines, or any excipient listed in the SmPC
• Are under 18 years of age

Tell your prescriber about all medicines you take. Interactions for Olmetec Plus include those from both the olmesartan and hydrochlorothiazide components:

• Lithium: olmesartan can increase lithium blood levels, and hydrochlorothiazide may further increase this risk. The combination with lithium is generally not recommended.
• Potassium supplements, potassium-sparing diuretics (such as spironolactone or amiloride), and potassium-containing salt substitutes: these can raise blood potassium to dangerous levels when combined with the olmesartan component.
• NSAIDs such as ibuprofen: regular use can reduce the blood pressure lowering effect of Olmetec Plus and increase the risk of kidney problems and electrolyte disturbances, particularly in older patients.
• Aliskiren: contraindicated in combination with olmesartan in patients with diabetes or significant kidney impairment.
• Antidiabetic medicines including insulin: hydrochlorothiazide may raise blood glucose levels, potentially reducing the effectiveness of antidiabetic treatment.
• Digoxin: hydrochlorothiazide induced low potassium can increase the risk of digoxin toxicity. Potassium monitoring is particularly important in patients taking both.
• Colesevelam: colesevelam reduces the absorption of hydrochlorothiazide. The SmPC advises that Olmetec Plus should be taken at least four hours before colesevelam.

Your prescriber will review all current medicines during the clinical assessment before any prescription is considered.

Olmetec Plus is a Prescription Only Medicine. The clinical consultation is the essential first step. A prescription will only be issued if a registered prescriber concludes, based on their individual assessment of your circumstances, that Olmetec Plus is clinically appropriate for you.

During your online consultation with Pharmacy Planet, a registered prescriber will review the information you provide. This includes your blood pressure history, your current antihypertensive treatment, kidney function and electrolyte results where available, and any other relevant medical information. The prescriber will assess whether Olmetec Plus is appropriate for your combination therapy needs, which strength is suitable, and whether the online service is appropriate for your situation.

If you are being managed for hypertension by your GP or a specialist, please keep them informed of all medicines prescribed through online services. Coordinated care supports safe and effective BP regulation and cardiovascular therapy.

• Store below 30°C.
• Store in the original packaging to protect from moisture.
• Keep out of the sight and reach of children.
• Do not use after the expiry date printed on the packaging.
• Do not dispose of medicines via household waste or wastewater. Return unused or out of date tablets to your pharmacist for safe disposal.
• Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

The table below compares combination tablets that contain two active ingredients in a single dose. These are prescribed when a single medicine does not provide adequate blood pressure control.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.

Pharmacy Planet is a GPhC-registered online pharmacy providing access to prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, clinical accuracy, and responsible prescribing.

We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service. Every prescription is reviewed and dispensed by qualified healthcare professionals. We provide clear, factual information to help patients understand their antihypertensive medication and make informed decisions about their combination therapy and cardiovascular therapy.

If you have questions about Olmetec Plus or any other medicine, our pharmacy team is available to help. We are committed to transparent, patient centred care.

References

1. Electronic Medicines Compendium (eMC). Olmetec Plus 20 mg/12.5 mg, 20 mg/25 mg and 40 mg/12.5 mg film-coated tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed May 2026.
2. National Institute for Health and Care Excellence (NICE). Hypertension in adults: diagnosis and management. NICE guideline NG136. https://www.nice.org.uk/guidance/ng136. Accessed May 2026.
3. NHS. High blood pressure (hypertension). https://www.nhs.uk/conditions/high-blood-pressure-hypertension. Accessed May 2026.
4. Joint Formulary Committee. British National Formulary (BNF). Olmesartan medoxomil with hydrochlorothiazide. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed May 2026.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Drug Safety Update: Olmesartan medoxomil (Olmetec, Olmetec Plus, Sevikar, Sevikar HCT): severe enteropathy. https://www.gov.uk/drug-safety-update. Accessed May 2026.
6. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed May 2026.