Isradipine


Concise Prescribing Info
Indications/Uses
HTN.
Dosage/Direction for Use
Adult : PO Initial: 2.5 mg bid, increase if necessary after 3-4 wk to 5 mg bid, up to 10 mg bid.
Dosage Details
Oral
Hypertension
Adult: Initially, 2.5 mg bid, increase if necessary after 3-4 wk to 5 mg bid, or 10 mg bid as required.
Elderly: Initially, 1.25 mg bid. Maintenance: 2.5 or 5 mg once daily.
Hepatic Impairment
Initially 1.25 mg bid. Maintenance: 2.5 or 5 mg once daily.
Administration
May be taken with or without food.
Contraindications
Cardiogenic shock, w/in 1 mth of MI, unstable angina, treatment of hypertensive crisis.
Special Precautions
Patients w/ CHF, severe aortic stenosis, hypertrophic cardiomyopathy w/ outflow tract obstruction. Hepatic impairment. Pregnancy and lactation.
Adverse Reactions
Headache, dizziness, palpitations, tachycardia, peripheral oedema, flushing, dyspnoea, abdominal discomfort, rash, pruritus, polyuria, fatigue, malaise.
MonitoringParameters
Monitor BP and heart rate esp during initiation of therapy or upward adjustment of dosage.
Overdosage
Symptoms: Excessive peripheral vasodilation w/ subsequent marked and prolonged systemic hypotension and tachycardia. Management: Symptomatic and supportive treatment. Emesis, gastric lavage, admin of activated charcoal followed in 30 min by a saline cathartic. A vasoconstrictor (e.g. epinephrine) may be useful in restoring normotensive state. Refractory hypotension or AV conduction disturbances may be treated w/ IV Ca salts or glucagon.
Drug Interactions
Concurrent admin w/ enzyme-inducing drugs (e.g. rifampicin, phenobarbital, carbamazepine) reduced plasma concentrations of isradipine. Increased bioavailability w/ cimetidine. May increase serum levels w/ CYP3A4 inhibitors (e.g. macrolides, HIV protease inhibitors, azole antifungals, delavirdine).
Food Interaction
Grapefruit juice may increase bioavailability of isradipine.
Action
Description: Isradipine is a dihydropyridine Ca channel blocker. It prevents Ca ions from entering the slow channels or select voltage-sensitive areas of vascular smooth muscle and myocardium during depolarisation, producing a relaxation of coronary vascular smooth muscle and coronary vasodilation.
Onset: 2-3 hr.
Duration: >12 hr.
Pharmacokinetics:
Absorption: Almost completely absorbed from the GI tract. Bioavailability: 15-24%. Time to peak plasma concentration: Approx 2 hr.
Distribution: Volume of distribution: 3 L/kg. Plasma protein binding: Approx 95%.
Metabolism: Metabolised hepatically via CYP3A4 isoenzyme. Undergoes extensive first-pass metabolism.
Excretion: Via urine (approx 70% as metabolites) and faeces. Terminal elimination half-life: Approx 8 hr.
Storage
Store below 30°C.
MIMS Class
References
Anon. Isradipine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 19/12/2013.

Buckingham R (ed). Isradipine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 19/12/2013.

Isradipine (Cobalt Laboratories). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 19/12/2013.

McEvoy GK, Snow EK, Miller J et al (eds). Isradipine. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 19/12/2013.

Wickersham RM. Isradipine. Facts and Comparisons [online]. St. Louis, MO. Wolters Kluwer Clinical Drug Information, Inc. https://www.wolterskluwercdi.com/facts-comparisons-online/. Accessed 19/12/2013.

Disclaimer: This information is independently developed by MIMS based on Isradipine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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