Isradipine
Isradipine (DynaCirc)
Isradipine
(iss- RAD-ih-peen)
Pregnancy Category: C DynaCirc DynaCirc CR (Rx)

Classification: Calcium channel blocking agent

See Also: See also Calcium Channel Blocking Agents .

Action/Kinetics: Binds to calcium channels resulting in the inhibition of calcium influx into cardiac and smooth muscle and subsequent arteriolar vasodilation. Reduced systemic resistance leads to a decrease in BP with a small increase in resting HR. In clients with normal ventricular function, the drug reduces afterload leading to some increase in CO. Well absorbed from the GI tract, although it undergoes significant first-pass metabolism. Peak plasma levels: 1 ng/mL after 1.5 hr. Onset: 2-3 hr. Food increases the time to peak effect by about 1 hr, although the total bioavailability does not change. t 1/2, initial: 1.5-2 hr; terminal, 8 hr. Completely metabolized in the liver with 60%-65% excreted through the kidneys and 25%-30% through the feces. Maximum effect may not be observed for 2-4 wks.

Uses: Alone or with thiazide diuretics in the management of essential hypertension. Investigational: Chronic stable angina.

Contraindications: Lactation.

Special Concerns: Safety and effectiveness have not been determined in children. Use with caution in clients with CHF, especially those taking a beta-adrenergic blocking agent. Bioavailability increases in those over 65 years of age, in impaired hepatic function, and in mild renal impairment.

Side Effects: CV: Palpitations, edema, flushing, tachycardia, SOB, hypotension, transient ischemic attack, stroke atrial fibrillation, ventricular fibrillation, MI CHF, angina. CNS: Headache, dizziness, fatigue, drowsiness, insomnia, lethargy, nervousness, depression, syncope, amnesia, psychosis, hallucinations, weakness, jitteriness, paresthesia. GI: Nausea, abdominal discomfort, diarrhea, vomiting, constipation, dry mouth. Respiratory: Dyspnea, cough. Dermatologic: Pruritus, urticaria. Miscellaneous: Chest pain, rash, pollakiuria, cramps of the legs and feet, nocturia, polyuria, hyperhidrosis, visual disturbances, numbness, throat discomfort, leukopenia, sexual difficulties.

Laboratory Test Alterations: LFTs.

Drug Interactions: Severe hypotension possible during fentanyl anesthesia with concomitant use of a beta-blocker and a calcium channel blocker.

How Supplied: Capsule: 2.5 mg, 5 mg ; Tablet, Extended Release: 5 mg, 10 mg

Dosage
?Capsules Hypertension.
Adults, initial: 2.5 mg b.i.d. alone or in combination with a thiazide diuretic. If BP is not decreased satisfactorily after 2-4 weeks, the dose may be increased in increments of 5 mg/day at 2 to 4-week intervals up to a maximum of 20 mg/day. Adverse effects increase at doses above 10 mg/day.
?Tablets, Controlled-Release Hypertension.
Adults: 5-10 mg once daily.