- See Dihydropyridine Calcium Channel Blocker
-
Dihydropyridines are primarily active at vascular Smooth Muscle
- Contrast with Non-Dihydropyridines which are also active at cardiac Smooth Muscle
- Amlodipine is a preferred first line oral antihypertensive Calcium Channel Blocker
- Long acting and less reflex Tachycardia than other Dihydropyridines, with improved cardiovascular outcomes
- Does not exacerbate Left Ventricular Dysfunction
- Consider avoiding in Diabetes Mellitus (relative contraindication)
- May increase Proteinuria
- NOT contraindicated in combination with Beta Blockers
- Contrast with Non-Dihydropyridine Calcium Channel Blockers (Diltiazem, Verapamil) which slow AV nodal conduction
- Relative contraindications (Exercise caution)
- See Dihydropyridine Calcium Channel Blocker
-
Clarithromycin
- Increases Calcium Channel Blocker levels via CYP3A4 inhibition especially with Dihydropyridines and over age 65 years
- Provokes Hypotension and Bradycardia
- Risk of Acute Kidney Injury (often requiring hospitalization)
- References
- Increases Calcium Channel Blocker levels via CYP3A4 inhibition especially with Dihydropyridines and over age 65 years
-
Simvastatin
- Limit Simvastatin to a maximum of 20 mg daily
- May increase other drug levels
- Potentiates other medications
- Adults with Hypertension
- Typical dose: 5 mg orally daily
- Start at 2.5 mg daily in elderly, frail patients or hepatic insufficiency
- Maximum: 10 mg orally daily (little benefit over 5 mg, but increased edema)
- Child with Hypertension
- Available as an oral suspension 1 mg/ml (Katerzia)
- Age under 6 years (NOT FDA approved)
- Start 0.1 to 0.2 mg/kg/day orally daily
- Maximum 0.3 mg/kg/day up to 10 mg orally daily
- Age 6 to 17 years old
- Start 2.5 mg orally daily
- May advance to 5 mg orally daily
- Combinations
- Amlodipine/Olmesartan (Azor)
- Amlodipine/Atorvastatin (Caduet)
- Amlodipine/Valsartan (Exforge)
- Amlodipine/Valsartan/Hydrochlorothiazide (Exforge HCT)
- Amlodipine/Benazepril (Lotrel)
- See Calcium Channel Blocker
-
Peripheral Edema
- Occurs more commonly in women
- Occurs more commonly on Norvasc doses >5 mg
- Adding ACE Inhibitor to regimen decreases edema
- Avoid Diuretics to reduce Dihydropyridine -induced edema
- Dihydropyridine-induced edema mechanism is vasodilation fluid leak into interstitium, NOT Sodium and water retention
- Slowest onset of action, but longest half life of the Dihydropyridine Calcium Channel Blockers
- Pregnancy Category C
- Avoid in Lactation
- Amlodipine Besylate Tablet (DailyMed)
- (2022) Presc Lett 29(11): 64-5
- (2022) Presc Lett, Resource #381108, Comparison of Calcium Channel Blockers
- (2020) Med Lett Drugs Ther 62(1598): 73-80
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 70-1
- Hamilton (2020) Tarascon Pocket Pharmacopoeia