What is Irbesartan Winthrop?
Irbesartan Winthrop is a medicine that contains the active substance irbesartan, which is available as white, oval tablets (75, 150 and 300 mg).
The medicine is similar to Aprovel, already authorized in the European Union (EU). The company that makes Aprovel has agreed that its scientific data can be used for Irbesartan Winthrop.
What is Irbesartan Winthrop used for?
Irbesartan Winthrop is used in patients with essential hypertension (high blood pressure). The term "essential" indicates that hypertension has no obvious cause. Irbesartan Winthrop is also used to treat kidney disease in patients with hypertension and type 2 diabetes (non-insulin-dependent diabetes). The use of Irbesartan Winthrop is not recommended in patients below 18 years of age because there is no information on safety and efficacy for this age group.
The medicine can only be obtained with a prescription.
How is Irbesartan Winthrop used?
Irbesartan Winthrop should be taken by mouth, with or without food. The usual recommended dose is 150 mg once a day. If the blood pressure is not sufficiently controlled, the dose can be increased to 300 mg a day or other medicines can be added for hypertension, such as hydrochlorothiazide. A starting dose of 75 mg can be used in patients undergoing hemodialysis (a blood purification technique) or in patients over 75 years of age.
In patients with hypertension and type 2 diabetes, Irbesartan Winthrop is associated with other treatments for hypertension. Treatment begins with a dose of 150 mg once a day, which is usually increased up to 300 mg once a day.
How does Irbesartan Winthrop work?
The active substance in Irbesartan Winthrop, irbesartan, is an "angiotensin II receptor antagonist", which means that it blocks the action of a hormone in the body called angiotensin II. Angiotensin II is a powerful vasoconstrictor (a substance that narrows blood vessels). By blocking the receptors to which angiotensin II normally attaches, irbesartan blocks the effect of the hormone, allowing the blood vessels to dilate. This causes a drop in blood pressure and reduces the risks associated with high blood pressure, such as stroke.
How has Irbesartan Winthrop been studied?
Irbesartan Winthrop was initially studied in 11 trials to evaluate its efficacy in blood pressure. Irbesartan Winthrop was compared with placebo (a dummy treatment) in a group of 712 patients and with other medicines for hypertension (atenol, enalaprin, or amlodipine) in 823 patients. The use of the medicine was also analyzed in combination with hydrochlorothiazide in 1, 736 patients. The main efficacy index was based on the reduction of diastolic blood pressure (the blood pressure measured in the interval between two heartbeats).
For the treatment of kidney disease, Irbesartan Winthrop has been studied in two large studies involving a total of 2, 326 patients with type 2 diabetes. Irbesartan Winthrop has been used for at least two years. One study looked at markers of kidney damage, measuring the eventual release of protein albumin in the urine by the kidneys. The second study was aimed at verifying whether Irbesartan Winthrop contributed to lengthening the period of time needed to double the creatinine levels in the patients' blood (a marker of kidney disease), until the need for dialysis or kidney transplantation arose or until death. In this study, Irbesartan Winthrop was compared to placebo and amlodipine.
What benefit has Irbesartan Winthrop shown during the studies?
In blood pressure studies, Irbesartan Winthrop was more effective than placebo in reducing the diastolic blood pressure and showed similar effects to other medicines for hypertension. Used in combination with hydrochlorothiazide, the two medicines showed an additional effect.
In the first kidney disease study, Irbesartan Winthrop was more effective than placebo in reducing the risk of kidney damage measured based on protein excretion. In the second kidney disease study, Irbesartan Winthrop reduced the risk of doubling blood creatinine levels, having to resort to kidney transplantation or dialysis or the risk of death during the study by 20% compared to placebo. There was a relative risk reduction of 23% compared to amlodipine. The main benefit was the effect on blood creatinine levels.
What is the risk associated with Irbesartan Winthrop?
The most common side effects with Irbesartan Winthrop (seen in between 1 and 10 patients in 100) are vertigo, nausea or vomiting, fatigue (tiredness) and increases in blood creatine kinase levels (an enzyme in the muscles). In addition, more than one in 100 patients with type 2 diabetes and kidney disease reported the following side effects: hyperkalemia (high levels of potassium in the blood), orthostatic vertigo (standing), orthostatic hypotension (low blood pressure being standing) and musculoskeletal (joint) pains. For the full list of all side effects reported with Irbesartan Winthrop, see the Package Leaflet.
Irbesartan Winthrop should not be used in people who may be hypersensitive (allergic) to irbesartan or any of the other ingredients. It must not be used in women who have been pregnant for more than three months. Not recommended for use during the first three months of pregnancy.
Why has Irbesartan Winthrop been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Irbesartan Winthrop's benefits are greater than its risks for the treatment of hypertension and kidney disease in patients with hypertension and type 2 diabetes mellitus. the marketing authorization for Irbesartan Winthrop is recommended.
More information on Irbesartan Winthrop:
On 19 January 2007, the European Commission granted an EU-wide marketing authorization for Irbesartan Winthrop to Sanofi Pharma Bristol-Myers Squibb SNC.
The full EPAR for Irbesartan Winthrop can be found here.
Last update of this summary: 03-2009.
