II. Mechanism
- Nifedipine (Procardia) is prototype for class
- Dihydropyridine Calcium Channel Blockers
- Dihydropyridines are primarily active at vascular Smooth Muscle
- Contrast with Non-Dihydropyridines which are also active at cardiac Smooth Muscle
III. Contraindications
- 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
IV. Drug Interactions
-
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
V. Preparations: Oral
- Amlodipine (Norvasc)
- Dosing
- Typical dose: 5 mg orally daily (may start at 2.5 mg daily in elderly)
- Maximum: 10 mg orally daily (little benefit over 5 mg, but increased edema)
- Advantages
- 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
- Dosing
-
Nifedipine (Procardia)
- Consider in Hypertension control in pregnancy (long safety record)
- Felodipine
- Nimodipine (Nymalize)
VI. Preparations: Parenteral (Hypertensive Emergency)
- Background
- Counter Cerebral Vessel spasm (e.g. early Subarachnoid Hemorrhage, CVA)
- Clevidipine (Cleviprex)
- Nicardipine
VII. Adverse Effects
- See Calcium Channel Blocker
-
Peripheral Edema (Norvasc)
- 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
VIII. References
- (2022) Presc Lett 29(11): 64-5
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Related Studies
| amlodipine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| AMLODIPINE BESYLATE 10 MG TAB | Generic | $0.02 each |
| AMLODIPINE BESYLATE 2.5 MG TAB | Generic | $0.01 each |
| AMLODIPINE BESYLATE 5 MG TAB | Generic | $0.01 each |
| AMLODIPINE-ATORVAST 10-10 MG | Generic | $1.09 each |
| AMLODIPINE-ATORVAST 10-20 MG | Generic | $2.38 each |
| AMLODIPINE-ATORVAST 10-40 MG | Generic | $1.32 each |
| AMLODIPINE-ATORVAST 10-80 MG | Generic | $4.03 each |
| AMLODIPINE-ATORVAST 5-10 MG | Generic | $2.08 each |
| AMLODIPINE-ATORVAST 5-20 MG | Generic | $1.13 each |
| AMLODIPINE-ATORVAST 5-40 MG | Generic | $1.50 each |
| AMLODIPINE-BENAZEPRIL 10-20 MG | Generic | $0.15 each |
| AMLODIPINE-BENAZEPRIL 10-40 MG | Generic | $0.16 each |
| AMLODIPINE-BENAZEPRIL 2.5-10 | Generic | $0.11 each |
| AMLODIPINE-BENAZEPRIL 5-10 MG | Generic | $0.11 each |
| AMLODIPINE-BENAZEPRIL 5-20 MG | Generic | $0.13 each |
| AMLODIPINE-BENAZEPRIL 5-40 MG | Generic | $0.16 each |
| AMLODIPINE-OLMESARTAN 10-20 MG | Generic | $0.39 each |
| AMLODIPINE-OLMESARTAN 10-40 MG | Generic | $0.40 each |
| AMLODIPINE-OLMESARTAN 5-20 MG | Generic | $0.36 each |
| AMLODIPINE-OLMESARTAN 5-40 MG | Generic | $0.45 each |
| AMLODIPINE-VALSARTAN 10-160 MG | Generic | $0.54 each |
| AMLODIPINE-VALSARTAN 10-320 MG | Generic | $0.70 each |
| AMLODIPINE-VALSARTAN 5-160 MG | Generic | $0.49 each |
| AMLODIPINE-VALSARTAN 5-320 MG | Generic | $0.58 each |
| norvasc (on 3/15/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| NORVASC 10 MG TABLET | Generic | $0.02 each |
| NORVASC 5 MG TABLET | Generic | $0.01 each |