isosorbide nitrates

Drug Name

Generic Name :  isosorbide nitrates , isosorbide dinitrate , isosorbide mononitrate

Brand Name:  Apo-ISDN (CAN), Dilatrate SR, Isordil, Isordil Titradose ,Imdur, ISMO, Isotrate ER, Monoket

Classification: Antianginal, Nitrate, Vasodilator

Pregnancy Category C 

Dosage & Route
ADULTS
  • To avoid tolerance to drug, take short-acting products bid or tid with last dose no later than 7 PM and SR products once daily or bid at 8 PM and 2 PM. This creates a nitrate-free period.

Isosorbide dinitrate

  • Angina pectoris: Starting dose, 2.5–5 mg sublingual, 5-mg chewable tablets, 5- to 20-mg oral tablets. For maintenance, 10–40 mg q 6 hr oral tablets or capsules; SR, initially 40 mg, then 40–80 mg PO q 8–12 hr.
  • Acute prophylaxis: Initial dosage, 5–10 mg sublingual or chewable tablets q 2–3 hr.

Isosorbide mononitrate

  • Prevention of angina: 20 mg PO bid given 7 hr apart; ER tablets—30–60 mg/day PO may be increased to 120 mg/day if needed. In smaller patients, start with 5 mg (one-half of 10-mg tablet) but then increase to at least 10 mg by day 2 or 3 of therapy. Give first dose when waking and second dose 7 hr later. This creates a nitrate-free period and minimizes tolerance to drug.
PEDIATRIC PATIENTS
  • Safety and efficacy not established.
Therapeutic actions
  • Relaxes vascular smooth muscle with a resultant decrease in venous return and decrease in arterial BP, which reduces left ventricular workload and decreases myocardial oxygen consumption.
Indications
  • Dinitrate: Treatment and prevention of angina pectoris
  • Mononitrate: Prevention of angina pectoris
  • Unlabeled use (dinitrate): Used with hydralazine in patients with advanced CHF
Adverse effects
  • CNS: Headache, apprehension, restlessness, weakness, vertigo, dizziness, faintness
  • CV: Tachycardia, retrosternal discomfort, palpitations, hypotension, syncope, collapse, orthostatic hypotension, angina, rebound hypertension, atrial fibrillation, postural hypertension
  • Dermatologic: Rash, exfoliative dermatitis, cutaneous vasodilation with flushing
  • GI: Nausea, vomiting, incontinence of urine and feces, abdominal pain, diarrhea
  • GU: Dysuria, impotence, urinary frequency
  • Other: Muscle twitching, pallor, perspiration, cold sweat, arthralgia, bronchitis
Contraindications
  • Contraindicated with allergy to nitrates, severe anemia, head trauma, cerebral hemorrhage, hypertrophic cardiomyopathy, narrow-angle glaucoma, postdural hypotension
  • Use cautiously with pregnancy, lactation, acute MI, CHF.
Nursing considerations

CLINICAL ALERT! Name confusion has occurred between Isordil (isosorbide) and Plendil (felodipine); use caution.

Assessment
  • History: Allergy to nitrates, severe anemia, GI hypermobility, head trauma, cerebral hemorrhage, hypertrophic cardiomyopathy, pregnancy, lactation
  • Physical: Skin color, T, lesions; orientation, reflexes, affect; P, BP, orthostatic BP, baseline ECG, peripheral perfusion; R, adventitious sounds; liver evaluation, normal output; CBC, Hgb
Interventions
  • Give sublingual preparations under the tongue or in the buccal pouch; discourage the patient from swallowing.
  • Create a nitrate-free period to minimize tolerance.
  • WARNING: Give chewable tablets slowly, only 5 mg initially, because severe hypotension can occur; ensure that patient does not chew or crush sustained-release preparations.
  • Give oral preparations on an empty stomach, 1 hr before or 2 hr after meals; take with meals if severe, uncontrolled headache occurs.
  • WARNING: Keep life support equipment readily available if overdose occurs or cardiac condition worsens.
  • WARNING: Gradually reduce dose if anginal treatment is being terminated; rapid discontinuation can lead to problems of withdrawal.
Teaching points
  • Place sublingual tablets under your tongue or in your cheek; do not chew or swallow the tablet. Take the isosorbide before chest pain begins, when activities or situation may precipitate an attack. Take oral isosorbide dinitrate on an empty stomach, 1 hour before or 2 hours after meals; do not chew or crush sustained-release preparations; do not take isosorbide mononitrate to relieve acute anginal episodes.
  • You may experience these side effects: Dizziness, lightheadedness (may be transient; use care to change positions slowly); headache (lie down in a cool environment, rest; over-the-counter preparations may not help; take drug with meals); flushing of the neck or face (reversible).
  • Report blurred vision, persistent or severe headache, rash, more frequent or more severe angina attacks, fainting.