DynaCirc, DynaCirc CR
Classifications: calcium channel blocker; antihypertensive; Therapeutic: antihypertensive; calcium channel blocker
Pregnancy Category: C
2.5 mg, 5 mg capsules; 5 mg, 10 mg sustained release tablets
Inhibits calcium ion influx into cardiac muscle and smooth muscle without changing calcium concentrations, thus affecting
contractility. Isradipine relaxes coronary vascular smooth muscle with little or no negative inotropic effect. It significantly
decreases systemic vascular resistance and reduces BP at rest and during isometric and dynamic exercise.
Reduces BP and has an antianginal effect.
Mild to moderate hypertension.
Hypersensitivity to isradipine; pregnancy (category C), lactation.
CHF, acute MI, severe bradycardia, cardiogenic shock, ventricular dysfunction; older adult; mild renal impairment, hepatic
impairment; GERD, hiatal hernia with esophageal reflux. Safety and effectiveness in children are not established.
Route & Dosage
Adult: PO 1.2510 mg b.i.d. (max: 20 mg/d); DynaCirc CR dosed q.d.
Adult: PO 2.57.5 mg t.i.d. (max: 15 mg/d)
- Do not crush sustained release form. It must be swallowed whole.
- Note: After the first 24 wk of therapy, dose may be increased for improved BP control in increments of 5 mg/d at 24
wk intervals up to a maximum dose of 20 mg/d.
- Store in tight, light-resistant container.
Adverse Effects (≥1%)CNS:
Headache, dizziness, fainting, fatigue
, sleep disturbances, vertigo. CV:
Flushing, ankle edema, palpitations, tachycardia, hypotension, chest pain, CHF. GI:
Nausea, vomiting, abdominal discomfort, constipation
, increased liver enzymes. Respiratory: Dyspnea
Rash, decreased skin sensation.
may prolong bradycardia. May increase cyclosporine
levels and toxicity
Rapidly and completely absorbed from GI tract, but only 1524% reaches systemic circulation because of first-pass
1 h. Peak:
23 h. Duration:
12 h. Distribution:
Not known if crosses placenta or is distributed into breast milk. Metabolism:
Extensive first-pass metabolism
in liver. Elimination:
70% in urine as inactive metabolites; 30% in feces. Half-Life:
Assessment & Drug Effects
- Monitor BP throughout course of therapy.
- Monitor patients with a history of CHF carefully, especially with concurrent beta blocker use. Promptly report S&S of worsening
- Monitor ambulation, especially with older adult patients, until response to drug is known.
Patient & Family Education
- Notify physician promptly of shortness of breath, palpitations, or other signs of adverse cardiovascular effects.
- Do not drive or engage in other potentially hazardous activities until response to drug is known.