Dosing & Uses
Dosage Forms & Strengths
tablet, extended release
Capsule: 2.5 PO q12hr; may increase dose q2-4week at 2.5-5 mg increments to maximum 20 mg/day (most patients show no improvement with doses >10 mg/day); maximum in older adults is 10 mg/day
Controlled release tablet: 5 mg PO qDay; may increase dose by 5 mg q2-4week; not to exceed 20 mg/day (freqency of adverse effects increases with doses >10 mg/day)
Dosage Forms & Strengths
tablet, extended release
Capsules: 2.5 mg PO q12hr initially
Controlled release tablet: 5 mg PO qDay initially
The bioavailabilty of isradipine is increased in the elderly population
Serious - Use Alternative
Significant - Monitor Closely
Chest pain (2-3%)
Diarrhea (≤ 3%)
Urinary frequency (1-3%)
Drug-induced gingival hyperplasia
Hypersensitivity to isradipine or other calcium channel blockers; hypotension (<90 mm Hg systolic)
Use caution in CHF, aortic stenosis, hypotension (initially or after dose increases), persistent progressive dermatologic reactions, exacerbation of angina (during initiation of treatment, after dose increase, or withdrawal of beta blocker), liver impairment
Reflex tachycardia resulting in angina and/or MI in patients with obstructive coronary disease reported
Peripheral edema may occur within 2-3 weeks of initiating therapy
Hypotension with or without syncope is possible (particularly with severe aortic stenosis)
Avoid taking with grapefruit juice
Pregnancy & Lactation
Pregnancy Category: C
Lactation: not known if excreted into breast milk
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Mechanism of Action
Ca channel blocker: inhibits the transmembrane influx of extracellular Ca ions across the membranes of myocardial cells and vascular smooth muscle cells, without changing serum calcium concentrations, resulting in inhibition of cardiac and vascular smooth muscle contraction, thereby dilating the main coronary and systemic arteries
Onset: 1 hr (initial response; regular release); 2 hr (SR)
Peak response: 2-3 hr (regular release); 8-10 hr (SR)
Excretion: Urine (60-65%); feces (30%)
Peak plasma time: 1.5-3 hr (regular release); 7-18 hr (SR)
Protein Bound: 95-97%
Vd: 3 L/kg
Metabolism: Hepatic P450 enzyme CYP3A4
Metabolites: Mono acids and a cyclic lactone product (inactive)
Clearance: 40 L/hr
Half-Life: 5-10.7 hr
Duration: 12 hr (regular release); 24 hr (SR)
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|1||This drug is available at the lowest co-pay. Most commonly, these are generic drugs.|
|2||This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.|
|3||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.|
|4||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|5||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|6||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|NC||NOT COVERED – Drugs that are not covered by the plan.|
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