about Chlorthalidone class, uses, side effects contraindications
Chlorthalidone
Short Description
Chlorthalidone is a thiazide diuretic.
The drug removes the excess water in the body and reduces fluid retention (Edema) in people with abundant?heart failure?, kidney disease, and cirrhosis of the liver.
Chlorthalidone is often used to treat?high blood pressure?, and because this medicine reduces the amount of calcium in the urine it is sometimes used to prevent certain types of kidney stones.
Chlorthalidone is more permanent than the rest of the group, but this medicine increases the loss of potassium and other salts in the urine.
Category
Chemical class: Phthalimidine derivative of benzenesulfonamide (thiazide-like diuretic)
Therapeutic class: Antihypertensive, diuretic
Pregnancy category: B
Indications
To reduce edema caused by heart failure, hepatic cirrhosis, corticosteroid or estrogen therapy, or renal dysfunction
Adults. Initial: 50 to 100 mg (Thalitone, 30 to 60 mg) daily, 100 mg (Thalitone, 60 mg) every other day, or 150 to 200 mg (Thalitone, 90 to 120 mg) daily or every other day. Maintenance: Individualized; may be lower than initial dosage. To treat hypertension
Adults. Initial: 25 mg daily (Thalitone, 15 mg daily). If response is insufficient, dosage increased to 50 mg daily (Thalitone, 30 to 50 mg daily). If additional control is required, dosage increased to 100 mg daily (except Thalitone) or a second antihypertensive added. Maintenance: Individualized; may be lower than initial dosage.
Mechanism of Action
May promote sodium, chloride, and water excretion by inhibiting sodium reabsorption in the distal tubules of the kidneys. Initially, chlorthalidone may decrease extracellular fluid volume, plasma volume, and cardiac output, which helps explain how it reduces blood pressure. It also may dilate arteries directly, which helps reduce peripheral vascular resistance and blood pressure. After several weeks, extracellular fluid and plasma volume and cardiac output return to normal, but peripheral vascular resistance remains decreased. Route Onset Peak Duration P.O. 2–3 hr 2–6 hr 24–72 hr
Contraindications
Anuria; hypersensitivity to chlorthalidone, other sulfonamides, or their components; renal decompensation
Interactions
allopurinol: Increased risk of allopurinol hypersensitivity amphotericin B, glucocorticoids: Intensified electrolyte depletion anesthetics: Potentiated effects of anesthetics anticholinergics: Increased chlorthalidone absorption antidiabetics, methenamines, oral anticoagulants, sulfonylureas: Decreased effects of these antihypertensives: Potentiated action of antihypertensives and chlorthalidone antineoplastics: Prolonged antineoplasticinduced leukopenia cholestyramine, colestipol: Decreased chlorthalidone absorption diazoxide: Increased risk of hyperglycemia and hypotension digitalis glycosides: Increased risk of digitalis-induced arrhythmias lithium: Decreased renal lithium clearance and increased risk of lithium toxicity loop diuretics: Increased synergistic effects, resulting in profound diuresis and serious electrolyte imbalances methyldopa: Potential development of hemolytic anemia neuromuscular blockers: Increased neuromuscular blockade
NSAIDs: Possibly reduced diuretic effect of chlorthalidone
vitamin D: Enhanced vitamin D action chlorthalidone 232
Side Efect
CNS: Dizziness, headache, insomnia, lightheadedness, paresthesia, restlessness, vertigo, weakness
CV: Orthostatic hypotension, vasculitis
EENT: Yellow vision
ENDO: Hyperglycemia
GI: Abdominal cramps or pain, anorexia, bloating, constipation, diarrhea, gastric irritation, nausea, pancreatitis, vomiting
GU: Decreased libido, impotence
HEME: Agranulocytosis, aplastic anemia, hypoplastic anemia, leukopenia, thrombocytopenia
MS: Gout attacks, muscle spasms
SKIN: Cutaneous vasculitis, exfoliative dermatitis, jaundice, necrotizing vasculitis, photosensitivity, purpura, rash, urticaria
Other: Hyperuricemia
Cautions
Use chlorthalidone cautiously in patients with impaired hepatic function or progressive hepatic disease because minor changes in fluid and electrolyte balance may cause hepatic coma. Assess BUN, serum electrolyte, uric acid, and blood glucose levels before therapy and periodically throughout therapy. Monitor patient for signs of fluid and electrolyte imbalance.
WARNING Monitor renal function periodically to detect cumulative drug effects, which may cause azotemia in patients with impaired renal function. PATIENT SAFTY
Stress the importance of taking chlorthalidone even when feeling well. Tell patient to store drug at room temperature in tightly closed container. Tell patient to take drug in the morning with food or milk. To minimize effects of orthostatic hypotension, instruct patient to rise slowly from a seated or lying position. Advise patient to check blood pressure regularly. Instruct patient to report signs of low potassium level, such as muscle weakness and fatigue. Advise patient to protect his skin from the sun. Urge patient to immediately report sudden joint pain to prescriber because drug can cause sudden gout attacks. Instruct patient to take a missed dose as soon as he remembers it. If he misses one day in an every-other-day schedule, tell him to take the dose on the off day and then resume usual dosing schedule. Warn against taking double or extra doses.
Trade Name & Company Name
effect of Chlorthalidone in Pregnancy, Fetal Health
and Breast feeding
Pregnancy
. Chlorthalidone is an oral diuretic with a prolonged action (48-72h). There are no adequate reports or well-controlled studies in pregnant women. Physiologic edema should not be treated. Thiazide diuretics may be diabetogenic. Severe electrolyte imbalances are reported in both mother and newborn. Hemorrhagic pancreatitis is also reported after thiazide exposure. Fetal Health
There are no adequate reports or well-controlled studies in human fetuses. Chlorthalidone crosses the placenta, achieving an F:M ratio approximating 0.15. Rodent studies are reassuring, revealing no evidence of teratogenicity or IUGR despite the use of doses higher than those used clinically. Breastfeeding
While chlorthalidone is excreted into human breast milk, the pharmacokinetics remain to be clarified. It is generally considered compatible with breastfeeding.
the follwing drugs will increse Chlorthalidone by inhepiting cyp450
the follwing drugs will decrease Chlorthalidone by inhancing cyp450
trad drugs based on Chlorthalidone
| Gen name | Trade name | Catagory name |
| atenolol / chlorthalidone | Tenoretic | Beta blockers with thiazides |
| atenolol / chlorthalidone | Tenoretic 100 | Beta blockers with thiazides |
| atenolol / chlorthalidone | Tenoretic 50 | Beta blockers with thiazides |
| chlorthalidone | Thalitone | Thiazide diuretics |
| chlorthalidone / clonidine | Clorpres | Antiadrenergic agents (central) with thiazides |
| Chlorthalidone | HYGROTON 50MG TABLETS | |
| Chlorthalidone | TENORETIC TAB | |
other drugs from same cataogory