MICARDIS® PLUS / MICARDIS® HCT

Telmisartan + Hydrochlorothiazide
Available strengths: 40/12.5 mg, 80/12.5 mg, 80/25 mg

Medical Description

MICARDIS PLUS (telmisartan/hydrochlorothiazide) is a fixed-dose combination antihypertensive medicine containing telmisartan, an angiotensin II receptor blocker (ARB), and hydrochlorothiazide (HCTZ), a thiazide diuretic.

It is indicated for the treatment of hypertension (high blood pressure) when blood pressure is not adequately controlled with telmisartan alone or when combination treatment is clinically appropriate. The two components lower blood pressure through complementary mechanisms: telmisartan blocks the effects of angiotensin II, while hydrochlorothiazide promotes renal sodium and water excretion.

WHO recognizes combination therapy using an ARB and a thiazide/thiazide-like diuretic as an established approach to pharmacological treatment of hypertension. Single-pill combinations can also simplify treatment regimens.

Available Strengths

The official prescribing information identifies these three fixed-dose combinations.

Indications

MICARDIS PLUS is used for:

• Treatment of arterial hypertension in adults.
• Patients whose blood pressure is insufficiently controlled with telmisartan monotherapy.
• Patients who require combination treatment with an ARB plus a thiazide diuretic.
• Patients already receiving the individual components at appropriate doses who may be switched to the corresponding fixed-dose combination.

Mechanism of Action

1. Telmisartan — Angiotensin II Receptor Blocker

Telmisartan selectively blocks the AT₁ receptor, preventing angiotensin II from exerting its major pressor effects.

Angiotensin II normally causes:

• Vasoconstriction
• Increased peripheral vascular resistance
• Aldosterone secretion
• Sodium and water retention

By blocking AT₁ receptors, telmisartan reduces angiotensin-II-mediated vasoconstriction and aldosterone activity, resulting in vasodilation and reduced blood pressure.

2. Hydrochlorothiazide — Thiazide Diuretic

Hydrochlorothiazide increases renal excretion of sodium and water, reducing extracellular fluid volume and contributing to a reduction in blood pressure.

With continued treatment, the antihypertensive effect also involves a reduction in peripheral vascular resistance.

Combination Effect

The two components act through different physiological pathways:

Telmisartan → blocks angiotensin II → reduces vasoconstriction and aldosterone effects

Hydrochlorothiazide → increases sodium/water excretion → reduces fluid volume

Their complementary actions provide greater blood-pressure reduction than either component may provide alone in appropriately selected patients.

Clinical Benefits

When appropriately prescribed, MICARDIS PLUS may:

• Lower elevated blood pressure.
• Provide complementary antihypertensive activity.
• Improve blood-pressure control when monotherapy is insufficient.
• Combine two prescribed antihypertensive agents into one daily tablet, which may simplify treatment.
• Help reduce the long-term cardiovascular risks associated with uncontrolled hypertension.

Effective treatment of hypertension is associated with reductions in cardiovascular complications including stroke and heart disease.

Dosage & Administration

MICARDIS PLUS is generally administered once daily, with the exact strength selected according to the patient's previous treatment and blood-pressure response.

• 40/12.5 mg: Telmisartan 40 mg + HCTZ 12.5 mg.
• 80/12.5 mg: Telmisartan 80 mg + HCTZ 12.5 mg.
• 80/25 mg: Telmisartan 80 mg + HCTZ 25 mg.

The prescribing information allows substitution of appropriately titrated individual components with the corresponding fixed-dose combination. Patients inadequately controlled with telmisartan 80 mg may be switched to 80/12.5 mg once daily, with further adjustment according to clinical response.

Administration:

• Take once daily at approximately the same time each day.
• MICARDIS PLUS may be taken with or without food.
• Swallow the tablet with water.
• Do not change the strength or discontinue treatment without medical advice.

Important Warnings & Precautions

Pregnancy
Telmisartan acts directly on the renin-angiotensin system and can cause serious fetal injury or death. MICARDIS PLUS should be discontinued as soon as pregnancy is detected and medical advice should be sought promptly.

Hypotension and dehydration
Patients who are volume-depleted because of excessive diuresis, vomiting, diarrhea, excessive sweating, or inadequate fluid intake may be particularly susceptible to symptomatic hypotension.

Kidney function
Renal function should be monitored in susceptible patients. The prescribing information states that usual treatment may be followed when creatinine clearance is >30 mL/min; MICARDIS PLUS is not recommended in more severe renal impairment because thiazide diuretics may be less effective and other diuretic strategies may be more appropriate. 

Electrolyte abnormalities
Hydrochlorothiazide may cause hypokalemia, hyponatremia and hypomagnesemia, whereas telmisartan may increase serum potassium. Periodic electrolyte monitoring may therefore be appropriate.

Hepatic impairment
Patients with biliary obstructive disorders or hepatic insufficiency require particular caution. The prescribing information recommends initiating treatment with the 40/12.5 mg combination under close medical supervision in such patients and does not recommend MICARDIS PLUS in severe hepatic impairment. 

Diabetes and uric acid
Hydrochlorothiazide may affect glucose metabolism and increase serum uric acid. Patients with diabetes or gout/hyperuricemia may require additional monitoring.

Possible Adverse Effects

Possible adverse effects include:

• Dizziness or lightheadedness
• Headache
• Fatigue
• Hypotension
• Increased urination
• Electrolyte disturbances
• Increased uric acid
• Changes in blood glucose

Less common but potentially serious adverse reactions include:

• Hyperkalemia or significant electrolyte abnormalities
• Renal impairment or acute kidney injury
• Severe hypotension
• Angioedema
• Hypersensitivity reactions
• Rare hydrochlorothiazide-associated acute myopia or secondary angle-closure glaucoma

Patients should seek urgent medical attention if swelling of the face, lips, tongue, or throat or difficulty breathing occurs.

Important Drug Interactions

Inform the physician or pharmacist about all medicines and supplements being used.

Important interactions include:

• Aliskiren — concomitant use with renin-angiotensin-system blockers is particularly important in patients with diabetes.
• ACE inhibitors or other ARBs — combined renin-angiotensin-system blockade can increase the risk of hypotension, hyperkalemia, and renal impairment.
• Potassium supplements or potassium-containing salt substitutes — may increase serum potassium.
• Potassium-sparing diuretics — may further increase potassium levels.
• NSAIDs — may reduce antihypertensive effects and increase the risk of renal impairment, especially in volume-depleted or renal-impaired patients.
• Lithium — thiazide diuretics and ARBs can increase lithium exposure and toxicity risk.
• Other antihypertensive or diuretic medicines may increase the risk of hypotension or electrolyte abnormalities.

Monitoring

Depending on the patient's clinical condition, healthcare professionals may monitor:

• Blood pressure
• Serum creatinine and eGFR
• Serum potassium
• Sodium and magnesium
• Blood glucose in susceptible patients
• Uric acid in patients at risk of gout
• Signs of dehydration or symptomatic hypotension

WHO recommends appropriate follow-up and monitoring as part of pharmacological hypertension management.

Storage

MICARDIS PLUS/HCT tablets are hygroscopic and require protection from moisture. Keep the tablets in their original packaging and store them according to the conditions stated on the product packaging. Keep out of the reach of children.

Medical Disclaimer

MICARDIS PLUS is a prescription antihypertensive medicine and should be used only under the supervision of a qualified healthcare professional. This information is provided for educational purposes and does not replace medical consultation, diagnosis, or individualized treatment. Do not start, stop, or change the dose without consulting your physician. Patients who are pregnant, planning pregnancy, or breastfeeding should seek medical advice before using this medicine. Inform your healthcare professional about any kidney, liver, heart, diabetes, gout, or electrolyte-related conditions and all medicines or supplements you are taking.

References

• U.S. National Library of Medicine — DailyMed: MICARDIS HCT (telmisartan/hydrochlorothiazide) Prescribing Information
• World Health Organization (WHO) — Guideline for the Pharmacological Treatment of Hypertension in Adults
• WHO — Evidence-to-Decision Framework for Combination Antihypertensive Therapy
• WHO — HEARTS Technical Package for Cardiovascular Disease Management