1. Overview

- Generic name: Irbesartan

- Brand names: Aprovel, Avapro

- Drug class: Angiotensin II receptor antagonist

Irbesartan is an antihypertensive agent belongs to a class of medicine called Angiotensin II receptor antagonist. It is used alone or in combination with other drugs to treat high blood pressure. It is also used in the treatment of kidney disease in patients with type 2 diabetes, who have high blood pressure and impaired kidney function.

This drug is also available in combination with hydrochlorothiazide (a diuretic) and sold under the brand name CoAprovel, it is used in the treatment of hypertension that is not treated by irbesartan alone.

Irbesartan is available as oral tablets only.

2. Uses

Irbesartan is a selective competitive antagonist of angiotensin II receptor. It acts by binding to this receptor and blocks its vasoconstrictor and aldosterone-secreting effects, hence causes vasodilation and lowers blood pressure.

Irbesartan is used in the treatment of:

1. Hypertension
2. Diabetic nephropathy in patients with type 2 diabetes and hypertension.
3. Lowering proteinuria in children with chronic kidney disease.
4. Left ventricular hypertrophy

3. Dosage forms & strengths

Irbesartan is available only as oral tablets

Irbesartan:

- 75 mg

- 150 mg

- 300 mg

Irbesartan/ hydrochlorothiazide:

- 150mg/12.5mg

- 300mg/ 25mg

- 300mg/ 12.5mg

4. How & when to take irbesartan

Irbesartan is used once daily, it can be taken without considering meals.

If you forget a dose, take the missed dose as soon as you remember, however, if you are supposed to take your next dose within 8 hours, take one dose now and skip the next dose.

Do not stop taking irbesartan without talking to your doctor. Stopping suddenly might worsen the condition.

This medicine may cause dizziness. You should avoid alcohol or driving while using this drug.

5. Special precautions

Make sure to tell your doctor if:

- You have sensitivity to irbesartan

- You have renal impairment

- You have renal artery stenosis

- You have angioedema

- You have heart failure

- You are taking other medicines

Pregnancy and breastfeeding

Irbesartan should not be prescribed during pregnancy because it can cause injury to the fetus. It must be discontinued once pregnancy is detected.

Irbesartan enters breast milk so might affect breastfed babies. Discussing with your doctor is necessary. Irbesartan is also not recommended for infants and children.

6. Who cannot use irbesartan?

Irbesartan is not suitable for certain individuals who:

• Have heart problems
• Are hypersensitive to irbesartan
• Have kidney problems
• Have renal artery stenosis
• Are pregnant or breastfeeding

In elderly dose reduction may be necessary, because there is a high risk of adverse effects.

7. Side effects

Side effects of irbesartan are usually mild and transient. The most common side effects of irbesartan include:

- Musculoskeletal pain

- Fatigue

- Nausea

- Headache

On rare occasions, you might have:

- Heartburn

- Rash

- Angioedema (swelling of face, eyes or any part of the body)

- Hepatotoxicity

Irbesartan side effects in detail

8. Interactions

Irbesartan can interact with several drugs and other substances resulting in undesired effects. Interaction can affect the activity of the drug or increase severity of side effects.

1. Diuretics: If these drugs are taken with irbesartan they will produce additive blood pressure lowering effect.
2. Potassium supplements, potassium sparing diuretics and Ciclosporin: these drugs may increase levels of potassium in the blood it they are used with irbesartan.
3. Antihypertensives: these drugs increase the effects of irbesartan.
4. Lithium: There will be an increased risk of lithium toxicity.
5. NSAIDs: Some of these drugs may reduce the hypotensive effect of irbesartan, and they may worsen kidney function.
6. ACE inhibitors: (e.g. enalapril, captopril, lisinopril or ramipril) increase potassium levels, and increase the risk of hypotension and nephrotoxicity.