Home Drug Guide Irbesartan

Drug Guide

Generic Name

Irbesartan

Brand Names Avapro

Classification

Therapeutic: Antihypertensive, Angiotensin II Receptor Blocker (ARB)

Pharmacological: Angiotensin II receptor antagonist

FDA Approved Indications

  • Hypertension
  • Diabetic nephropathy in patients with type 2 diabetes and hypertension

Mechanism of Action

Irbesartan blocks the angiotensin II receptors in vascular smooth muscle and the adrenal gland, leading to vasodilation and decreased aldosterone secretion, which reduces blood pressure.

Dosage and Administration

Adult: Typically 150 mg once daily, titrated up to 300 mg once daily as needed, depending on response.

Pediatric: Not recommended for children under 6 years old; for children aged 6 years and older, dosing should be individualized.

Geriatric: Monitor renal function and electrolytes; start at lower doses due to potential increased sensitivity.

Renal Impairment: Reduce dose in patients with creatinine clearance less than 60 mL/min; careful monitoring required.

Hepatic Impairment: Use with caution, starting with lower doses due to potential for increased exposure.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Extensive, approximately 95% protein-bound.

Metabolism: Partially metabolized in the liver; minor 6-hydroxymethyl and carboxylic acid metabolites.

Excretion: Excreted primarily in feces (about 70%) and urine (about 25%).

Half Life: Approximately 11-15 hours.

Contraindications

  • History of hypersensitivity to irbesartan or other ARBs
  • Pregnancy (especially at 2nd and 3rd trimesters)

Precautions

  • Renal impairment, concomitant use with other agents affecting renal function, volume depletion, hyperkalemia, avoid during pregnancy and breastfeeding unless specifically advised.

Adverse Reactions - Common

  • Hypotension (Uncommon)
  • Dizziness (Common)
  • Fatigue (Common)
  • Elevated serum potassium (Uncommon)

Adverse Reactions - Serious

  • Angioedema (Rare)
  • Acute renal failure (Uncommon)
  • Hyperkalemia (Uncommon)

Drug-Drug Interactions

  • Enhances hypotensive effect when combined with other antihypertensives, potassium-sparing diuretics, or potassium supplements.
  • NSAIDs may reduce the antihypertensive effect and increase risk of renal impairment.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, renal function, and serum electrolytes regularly.

Diagnoses:

  • Ineffective tissue perfusion related to hypotension.
  • Risk for electrolyte imbalance.

Implementation: Administer as prescribed, preferably at the same time each day. Monitor for signs of hypotension and hyperkalemia.

Evaluation: Assess blood pressure response and adverse effects.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report signs of dizziness, swelling, or difficulty breathing.
  • Avoid potassium-rich foods and potassium supplements unless directed.
  • Maintain hydration and follow dietary recommendations.

Special Considerations

Black Box Warnings:

  • Pregnancy risk; discontinue as soon as pregnancy is detected.
  • Fetal toxicity can result in fetal death or injury.

Genetic Factors: Not specifically related to genetic factors.

Lab Test Interference: May cause increases in serum potassium and serum creatinine.

Overdose Management

Signs/Symptoms: Severe hypotension, tachycardia or bradycardia, dizziness, hyperkalemia.

Treatment: Discontinue drug, initiate supportive care including IV fluids; consider vasopressors for persistent hypotension; monitor serum electrolytes and renal function.

Storage and Handling

Storage: Store at room temperature away from moisture, heat, and light.

Stability: Stable under recommended storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.