Amlodipine + Hydrochlorothiazide
Indications
Amlodipine + Hydrochlorothiazide is used for:
Essential Hypertension
Adult Dose
Oral
Adult 1 tab once daily.
Child Dose
Renal Dose
CrCl >30 mL/min: No dosage adjustment required
CrCl 30 mL/min or less: Avoid use; loop diuretics are preferred to thiazides with severe renal impairment; thiazides may precipitate azotemia
Administration
May be taken with or without food: Take at the same time of the day & preferably in the morning. Swallow whole w/ water.
Contra Indications
Hypersensitivity to sulfonamides. Severe hepatic & renal impairment (CrCl <30 mL/min), anuria, refractory hypokalaemia, hyponatraemia, hypercalcaemia & symptomatic hyperuricaemia. Pregnancy.
Precautions
Angioedema, severe CHF, surgery/anesthesia, volume depletion (consider lower dose)
Discontinue STAT if pregnant: potential risk of congenital malformations
Risk of hypotension, especially in patients with volume/salt depletion; correct volume-depletion prior to administration
Increased angina or myocardial infarction with calcium channel blockers may occur upon dosage initiation or increase
Avoid with severe renal impairment (<30 mL/min)
Withhold/discontinue if progressive renal impairment occurs
Thiazides: use with caution with mild/moderate liver impairment or progressive liver disease; avoid in patients with severe liver impairment
Monitor for fluid/electrolyte imbalance
Use caution in heart failure, severe aortic stenosis (amlodipine), hepatic impairment, renal artery stenosis, or hypertrophic cardiomyopathy
Thiazide diuretics may exacerbate or activate SLE
Acute transient myopia and acute angle-closure glaucoma has been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is a sulfonamide)
Caution in aortic mitral stenosis, hepatic impairment, hypercholesterolemia, hypercalcemia, parathyroid disease, pre-existing renal insufficiency, systemic lupus erythematosus, bilateral renal artery stenosis or anuria
Pregnancy-Lactation
Interactions
Adverse Effects
Side effects of Amlodipine + Hydrochlorothiazide :
1-10%
Dizziness (5.8-8.9%)
Peripheral edema (7.7%)
Fatigue (4%)
Headache (6.4%)
Nausea (3%)
Muscle spasms (3.1%)
Nausea (3%)
Diarrhea (2.6%)
Joint swelling (2.1%)
Syncope (1%)
Urinary tract infection (2%)
Nasopharyngitis (4%)
Upper respiratory tract infection (3%)
Mechanism of Action
Amlodipine: Dihydropyridine calcium channel blocker; inhibits extracellular Ca ions across the membranes of myocardial cells and vascular smooth muscle cells, without changing serum calcium concentrations; this results in inhibition of cardiac and vascular smooth muscle contraction, thereby dilating the main coronary and systemic arteries
Hydrochlorothiazide: Thiazide diuretic; Inhibits Na reabsorption in distal renal tubules resulting in increased Na and water excretion; lowers blood pressure and decreases edema