Giran-H8 mg+12.5 mg

Giran-H is a fixed-dose combination antihypertensive indicated for the treatment of hypertension.

Evidence-based classification of use

• Established/guideline-supported use: Treatment of hypertension in adult patients not adequately controlled on candesartan cilexetil or hydrochlorothiazide monotherapy alone.
• Combination-dependent use: Giran-H may also be used as initial therapy in patients whose blood pressure is markedly above goal and who are likely to require more than one agent to reach target blood pressure, as judged by the treating physician; it is not intended as routine first-line monotherapy substitution.
• Replacement therapy: Giran-H can be used to replace the individually titrated components (candesartan cilexetil and hydrochlorothiazide) given concurrently, for patients already stable and controlled on that combination, to simplify the dosing regimen.

Giran-H is not indicated for the initial treatment of hypertensive emergencies, and is not recommended for use in pregnancy (see Contraindications and Pregnancy and Lactation).

Candesartan Cilexetil + Hydrochlorothiazide tablets combine two active pharmaceutical ingredients in a single fixed-dose formulation:

• Candesartan Cilexetil - an angiotensin II receptor blocker (ARB), a prodrug that is hydrolyzed to the active moiety candesartan during absorption from the gastrointestinal tract.
• Hydrochlorothiazide - a thiazide diuretic.

Locally marketed strengths of Candesartan Cilexetil + Hydrochlorothiazide typically combine candesartan cilexetil 16 mg or 32 mg with hydrochlorothiazide 12.5 mg or 25 mg per tablet; exact strengths vary by manufacturer and market authorization, and the prescribed strength should always be confirmed against the dispensed product label.

Giran-H is an oral fixed-dose combination product developed to simplify antihypertensive therapy for patients who need both an angiotensin II receptor blocker and a thiazide diuretic to control blood pressure. By combining a renin-angiotensin system blocker with a diuretic that acts through a complementary mechanism in the distal nephron, Giran-H produces an additive antihypertensive effect while also helping to counteract the mild potassium loss and compensatory renin release associated with each individual component when used alone.

Giran-H is taken once daily, orally, with or without food, and is intended for long-term, ongoing management of chronic hypertension rather than short-term or as-needed use.

Giran-H belongs to the therapeutic class of fixed-dose combination antihypertensives, pairing an angiotensin II receptor blocker (ARB) with a thiazide diuretic.

Mechanism of action

Candesartan Cilexetil + Hydrochlorothiazide combines two agents with complementary and additive antihypertensive mechanisms:

• Candesartan selectively blocks the binding of angiotensin II to the AT1 receptor subtype in vascular smooth muscle and the adrenal gland, blocking the vasoconstrictor and aldosterone-secreting effects of angiotensin II. This reduces peripheral vascular resistance without the reflex tachycardia commonly seen with direct vasodilators, and without significantly affecting the metabolism of bradykinin.
• Hydrochlorothiazide inhibits the sodium-chloride symporter in the distal convoluted tubule of the nephron, increasing excretion of sodium, chloride, and water, and secondarily increasing potassium and magnesium excretion. The resulting reduction in plasma volume contributes to its antihypertensive effect, while chronic thiazide use also produces some direct reduction in peripheral vascular resistance.

Pharmacokinetics

Candesartan cilexetil is rapidly and completely hydrolyzed to active candesartan during absorption from the gastrointestinal tract; candesartan is highly protein bound and is eliminated largely unchanged via renal and biliary excretion, with an effective half-life of approximately 9 hours. Hydrochlorothiazide is absorbed from the gastrointestinal tract and is eliminated primarily unchanged by the kidney, with a half-life of 6 to 15 hours. The onset of antihypertensive effect of Candesartan Cilexetil + Hydrochlorothiazide occurs within a few hours of the first dose, with the full effect generally seen after 4 weeks of continued once-daily dosing.

Giran-H tablets should be swallowed whole with a glass of water, once daily, at approximately the same time each day, with or without food. Do not crush or chew unless specifically directed by a physician or pharmacist. If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose, in which case the missed dose should be skipped; doses should never be doubled.

Giran-H has several clinically significant drug interactions that should be reviewed before co-administration:

• Lithium: Both angiotensin II receptor blockers and thiazide diuretics can reduce renal lithium clearance, increasing serum lithium levels and the risk of lithium toxicity; concurrent use should be undertaken with careful monitoring of lithium levels.
• NSAIDs (including selective COX-2 inhibitors): May reduce the antihypertensive effect of Giran-H and, particularly in elderly, volume-depleted, or renally impaired patients, may increase the risk of acute kidney injury.
• Potassium-sparing diuretics, potassium supplements, salt substitutes, ACE inhibitors, or other ARBs: Concomitant use may increase the risk of hyperkalemia; dual blockade of the renin-angiotensin system generally offers no added benefit and increases the risk of hyperkalemia, hypotension, and renal impairment compared with either agent alone.
• Aliskiren: Contraindicated in patients with diabetes due to increased risk of hyperkalemia, hypotension, and renal impairment (see Contraindications); use with caution and close monitoring in other patients.
• Digoxin: Thiazide-induced hypokalemia or hypomagnesemia can predispose to digoxin toxicity; electrolytes should be monitored.
• Corticosteroids or ACTH: May intensify electrolyte depletion, particularly hypokalemia, caused by the hydrochlorothiazide component.
• Cholestyramine or colestipol: May reduce absorption of hydrochlorothiazide; Giran-H should be dosed apart from these agents.
• Alcohol, barbiturates, or narcotics: May potentiate orthostatic hypotension.
• Antidiabetic agents (insulin or oral hypoglycemics): The hydrochlorothiazide component may raise blood glucose and require dose adjustment of antidiabetic therapy.

Most patients tolerate Giran-H well. Reported adverse effects include:

• Common: Dizziness, headache, upper respiratory tract infection, back pain, fatigue, and hypotension, particularly after the first dose or with dose increases.
• Related to the hydrochlorothiazide component: Hypokalemia, hyperuricemia (occasionally precipitating gout), hyperglycemia, photosensitivity reactions, and mild gastrointestinal upset.
• Related to the candesartan component: Hyperkalemia, and rarely, angioedema.
• Less common but serious: Symptomatic hypotension, significant electrolyte disturbances (hyponatremia, hypomagnesemia, hypochloremic alkalosis), and deterioration of renal function, particularly in susceptible patients.

Patients should seek prompt medical attention for signs of angioedema (swelling of the face, lips, tongue, or throat, difficulty breathing), severe dizziness, or fainting.

Pregnancy: Giran-H is contraindicated in pregnancy. Drugs that act directly on the renin-angiotensin system, including the candesartan component of Giran-H, can cause fetal injury or death when used during the second and third trimesters. Giran-H should be discontinued as soon as possible once pregnancy is detected, and an alternative antihypertensive agent considered under medical supervision.

Lactation: It is not known whether candesartan is excreted in human milk, but hydrochlorothiazide is excreted in breast milk. Because of the potential for adverse effects in a nursing infant, a decision should be made whether to discontinue breastfeeding or discontinue Giran-H, taking into account the importance of the drug to the mother; use only if clearly needed and after consulting a physician.

Boxed warning

Giran-H can cause fetal harm or death when used during pregnancy. Giran-H should be discontinued as soon as pregnancy is detected (see Contraindications and Pregnancy and Lactation).

Other precautions

• Hypotension: Symptomatic hypotension may occur, especially after the initial dose or dose increases, and in patients who are volume- or salt-depleted (e.g., from prior diuretic therapy, vomiting, diarrhea, or restricted salt intake); volume depletion should be corrected before starting Giran-H.
• Renal function: Giran-H should be used with caution in patients with renal impairment or renal artery stenosis, as changes in renal function, including acute renal failure, can occur, particularly in volume-depleted patients or those with pre-existing renal disease. Periodic monitoring of renal function is recommended.
• Hyperkalemia: The candesartan component can cause hyperkalemia, particularly in patients with renal impairment, diabetes mellitus, or those taking potassium-sparing diuretics, potassium supplements, or salt substitutes containing potassium.
• Electrolyte disturbances: The hydrochlorothiazide component can cause hypokalemia, hyponatremia, hypomagnesemia, and hypochloremic alkalosis; periodic monitoring of serum electrolytes is recommended, particularly in patients at higher risk (e.g., the elderly, those on other diuretics, or with inadequate oral intake).
• Metabolic effects: The hydrochlorothiazide component may cause hyperuricemia, precipitate gout in susceptible patients, and may worsen glycemic control in patients with diabetes; blood glucose monitoring may be warranted.
• Sulfonamide hypersensitivity: Hydrochlorothiazide is a sulfonamide-derived drug; allergic reactions are possible in patients with a history of allergy to sulfonamides or sulfonamide-derived drugs.
• Photosensitivity: Photosensitivity reactions have been reported with thiazide diuretics; reasonable sun protection measures are advised.
• Dual RAAS blockade: Concomitant use of Giran-H with other angiotensin II receptor blockers, ACE inhibitors, or aliskiren is generally not recommended due to increased risk of hyperkalemia, hypotension, and renal impairment without added clinical benefit.

The most likely manifestation of Giran-H overdose is symptomatic hypotension, along with possible electrolyte disturbances (particularly hypokalemia) and dehydration from the diuretic component. In the event of a suspected overdose, seek immediate medical attention or contact emergency services or a poison control center. Management is supportive and symptomatic; there is no specific antidote. Treatment may include monitoring of vital signs, supine positioning with leg elevation, and cautious volume and electrolyte replacement under medical supervision. Candesartan is not removed by hemodialysis; the dialyzability of hydrochlorothiazide has not been established.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

• Renal impairment: Giran-H should be used with caution in patients with renal impairment, with periodic monitoring of renal function and serum electrolytes; thiazide diuretics may be less effective in patients with significantly reduced renal function, and Giran-H is generally not recommended in severe renal impairment.
• Hepatic impairment: Use with caution, as minor alterations of fluid and electrolyte balance may precipitate hepatic coma in patients with impaired hepatic function or progressive liver disease.
• Elderly: No overall differences in safety or effectiveness have been observed between elderly and younger patients, but elderly patients may be more sensitive to blood-pressure-lowering and electrolyte effects; initiate therapy with caution.
• Pediatric use: Safety and efficacy of the fixed-dose combination Giran-H have not been established in pediatric patients (see Pediatric Uses).
• Volume-depleted patients: Correct volume or salt depletion before initiating Giran-H to reduce the risk of symptomatic hypotension.

Giran-H is intended for long-term, continuous use in the chronic management of hypertension. It is not intended for short-term or as-needed use. Blood pressure control and relevant laboratory parameters (renal function, electrolytes) should be reassessed periodically by the prescribing physician, who will determine the appropriate duration of therapy, which is typically indefinite for ongoing blood pressure control unless otherwise directed.

Angiotensin II Receptor Blocker (ARB) + Thiazide Diuretic (fixed-dose combination antihypertensive)

Candesartan Cilexetil + Hydrochlorothiazide works through two complementary mechanisms: candesartan selectively blocks the AT1 receptor, preventing angiotensin II from causing vasoconstriction and aldosterone release, thereby lowering blood pressure; hydrochlorothiazide inhibits sodium and chloride reabsorption in the distal convoluted tubule of the nephron, increasing urinary sodium and water excretion and reducing plasma volume. The combined effect of reduced vascular resistance and reduced circulating volume produces an additive antihypertensive effect greater than either component alone.

D

The safety and efficacy of the fixed-dose combination Giran-H have not been established in pediatric patients. Giran-H is not recommended for use in children, and pediatric hypertension, when it requires an ARB and/or thiazide diuretic, should generally be managed with the individual components under specialist pediatric care rather than with the fixed-dose combination, in line with conservative pediatric labeling positions for this combination product.