Eprosartan and hydrochlorothiazide
Eprosartan and hydrochlorothiazide Uses, Dosage, Side Effects, Food Interaction and all others data.
Eprosartan is an angiotensin II receptor antagonist used to treat hypertension. It performs 2 actions on the renin angiotensin system. By preventing the binding of angiotensin II to AT1, vascular smooth muscle relaxes and vasodilation occurs. By inhibiting norepinephrine production, blood pressure is further reduced.
Angiotensin II, the principal pressor agent of the renin-angiotensin system, is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme [kininase II]. It is responsible for effects such as vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Eprosartan selectively blocks the binding of angiotensin II to the AT1 receptor, which in turn leads to multiple effects including vasodilation, a reduction in the secretion of vasopressin, and reduction in the production and secretion of aldosterone. The resulting effect is a decrease in blood pressure.
Thiazides such as hydrochlorothiazide promote water loss from the body (diuretics). They inhibit Na+/Cl- reabsorption from the distal convoluted tubules in the kidneys. Thiazides also cause loss of potassium and an increase in serum uric acid. Thiazides are often used to treat hypertension, but their hypotensive effects are not necessarily due to their diuretic activity. Thiazides have been shown to prevent hypertension-related morbidity and mortality although the mechanism is not fully understood. Thiazides cause vasodilation by activating calcium-activated potassium channels (large conductance) in vascular smooth muscles and inhibiting various carbonic anhydrases in vascular tissue.
Hydrochlorothiazide prevents the reabsorption of sodium and water from the distal convoluted tubule, allowing for the increased elimination of water in the urine. Hydrochlorothiazide has a wide therapeutic window as dosing is individualized and can range from 25-100mg. Hydrochlorothiazide should be used with caution in patients with reduced kidney or liver function.
| Trade Name | Eprosartan and hydrochlorothiazide |
| Generic | Eprosartan + hydrochlorothiazide |
| Type | Oral |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | United States |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Eprosartan is an ARB used to treat hypertension, diabetic nephropathy, and congestive heart failure.
For the management of hypertension alone or in combination with other classes of antihypertensive agents. Also used as a first-line agent in the treatment of diabetic nephropathy, as well as a second-line agent in the treatment of congestive heart failure (only in those intolerant of ACE inhibitors).
Hydrochlorothiazide is used for-
- Edema associated with congestive heart failure, hepatic cirrohosis, various forms of renal dysfunction and corticosteroid and estrogen therapy
- Management of hypertension either as the sole therapeutic agent or to enhance the effectiveness of other antihypertensive drugs in the more severe form of hypertension
- Management of diabetes insipidus
- Management of proximal renal tubular acidosis
- Idiopathic hypercalciuria and calcium nephrolithiasis, osteoporosis and exercise induced hyperkalemia
Eprosartan and hydrochlorothiazide is also used to associated treatment for these conditions: Congestive Heart Failure (CHF), Diabetic Nephropathy, High Blood Pressure (Hypertension)Acidosis, Renal Tubular, Calcium Nephrolithiasis, Cirrhosis of the Liver, Congestive Heart Failure (CHF), Diabetes Insipidus, Edema, High Blood Pressure (Hypertension), Hypertension,Essential, Hypokalemia caused by diuretics, Nephrotic Syndrome, Premenstrual tension with edema, Sodium retention, Stroke, Prophylaxis of preeclampsia
How Eprosartan and hydrochlorothiazide works
Eprosartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor found in many tissues (e.g., vascular smooth muscle, adrenal gland). There is also an AT2 receptor found in many tissues but it is not known to be associated with cardiovascular homeostasis. Eprosartan does not exhibit any partial agonist activity at the AT1 receptor. Its affinity for the AT1 receptor is 1,000 times greater than for the AT2 receptor. In vitro binding studies indicate that eprosartan is a reversible, competitive inhibitor of the AT1 receptor. Eprosartan has also been shown to bind to AT1 receptors both presynaptically and synaptically. Its action on presynaptic AT1 receptors results in the inhibition of sympathetically stimulated noradrenaline release. Unlike ACE inhibitors, eprosartan and other ARBs do not interfere with response to bradykinins and substance P, which allows for the absence of adverse effects that are present in ACE inhibitors (eg. dry cough).
Hydrochlorothiazide is transported from the circulation into epithelial cells of the distal convoluted tubule by the organic anion transporters OAT1, OAT3, and OAT4. From these cells, hydrochlorothiazide is transported to the lumen of the tubule by multidrug resistance associated protein 4 (MRP4).
Normally, sodium is reabsorbed into epithelial cells of the distal convoluted tubule and pumped into the basolateral interstitium by a sodium-potassium ATPase, creating a concentration gradient between the epithelial cell and the distal convoluted tubule that promotes the reabsorption of water.
Hydrochlorothiazide acts on the proximal region of the distal convoluted tubule, inhibiting reabsorption by the sodium-chloride symporter, also known as Solute Carrier Family 12 Member 3 (SLC12A3). Inhibition of SLC12A3 reduces the magnitude of the concentration gradient between the epithelial cell and distal convoluted tubule, reducing the reabsorption of water.
Dosage
Eprosartan and hydrochlorothiazide dosage
Adults-
For Edema: The usual adult dosage is 25 to 100 mg daily as a single or divided dose.
For Control of Hypertension: The usual initial dose in adults is 25 mg daily given as a single dose. The dose may be increased to 50 mg daily, given as a single or two divided doses. Doses above 50 mg are often associated with marked reductions in serum potassium. In some patients (especially the elderly) an initial dose of 12.5 mg daily may be sufficient.
Infants and children-
For diuresis and for control of hypertension: The usual pediatric dosage is 1 to 2 mg/kg/day in single or two divided doses, not to exceed 37.5 mg per day in infants up to 2 years of age or 100 mg per day in children 2 to 12 years of age. In infants less than 6 months of age, doses up to 3 mg/kg/day in two divided doses may be required.
Side Effects
Generally, Hydrochlorothiazide is well tolerated. However, a few side effects may occur like weakness, restlessness, dizziness, headache, fever, diarrhea, vomiting, sialadenitis, cramping, constipation, gastric irritation, nausea, anorexia, and hypotension. In rare case hyperglycemia, glycosuria, hyperuricemia and muscle spasm may occur.
Toxicity
There was no mortality in rats and mice receiving oral doses of up to 3000 mg eprosartan/kg and in dogs receiving oral doses of up to 1000 mg eprosartan/kg.
The oral LD50 of hydrochlorothiazide is >10g/kg in mice and rats.
Patients experiencing an overdose may present with hypokalemia, hypochloremia, and hyponatremia. Treat patients with symptomatic and supportive treatment including fluids and electrolytes. Vasopressors may be administered to treat hypotension and oxygen may be given for respiratory impairment.
Precaution
Thiazides should be used with caution in patients with severe renal disease, impaired hepatic function or progressive liver disease and gout.
Interaction
Alcohol, Barbiturates, or Narcotics: Potentiation of orthostatic hypotension may occur.
Antidiabetic Drugs (oral agents and insulin): Thiazides can impair control of diabetes mellitus by diet and antidiabetic Drugs. Antihypertensive Drugs: Additive effect or potentiation.
Volume of Distribution
The volume of distribution varies widely from one study to another with values of 0.83-4.19L/kg.
Elimination Route
Absolute bioavailability following a single 300 mg oral dose of eprosartan is approximately 13%. Administering eprosartan with food delays absorption.
An oral dose of hydrochlorothiazide is 65-75% bioavailable, with a Tmax of 1-5 hours, and a Cmax of 70-490ng/mL following doses of 12.5-100mg. When taken with a meal, bioavailability is 10% lower, Cmax is 20% lower, and Tmax increases from 1.6 to 2.9 hours.
Half Life
The terminal elimination half-life of eprosartan following oral administration is typically 5 to 9 hours.
The plasma half life of hydrochlorothiazide is 5.6-14.8h.
Clearance
The renal clearance of hydrochlorothiazide in patients with normal renal function is 285mL/min. Patients with a creatinine clearance of 31-80mL/min have an average hydroxychlorothiazide renal clearance of 75mL/min, and patients with a creatinine clearance of ≤30mL/min have an average hydroxychlorothiazide renal clearance of 17mL/min.
Elimination Route
Hydrochlorothiazide is eliminated in the urine as unchanged hydrochlorothiazide.
Pregnancy & Breastfeeding use
Pregnancy: Evidence of fetal risk in hydrochlorothiazide therapy is found, but it is indicated if benefits outweigh risks. Thiazides are indicated in pregnancy when edema is due to pathologic causes.\
Lactation: Neonatal side effects have been seen incase of hydrochlorothiazide therapy and therefore it is not recommended.
Contraindication
Hydrochlorothiazide is contraindicated to the patients of anuria and those who are sensitive to hydrochlorothiazide or to other sulfonamide-derived drugs. Therapy is not to be initiated in diabetes mellitus.
Special Warning
Elderly: in some patients specially the elderly an initial dose of 12.5 mg daily may be sufficient.
Children: An initial dose for children has been 1 to 2 mg per kg body-weight in 2 divided doses. Infants under 6 months may need doses upto 3 mg per kg daily.
Acute Overdose
The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis. Rarely, autoimmune hemolytic anemia and other hypersensitivity reactions may complicate the picture.
In the event of over dosage, symptomatic and supportive measures should be employed. Emesis should be induced or gastric lavage performed. Correct dehydration, electrolyte imbalance, hepatic coma and hypotension by established procedures. Hemodialysis can be used successfully to treat severe intoxication.
Storage Condition
Store between 15-30°C. Protect from light, moisture and freezing.
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