Generic
Isosorbide Dinitrate
2 brands available in the market
At a glance
Isosorbide Dinitrate is used to prevent angina (chest pain). It relaxes and widens blood vessels so blood can flow more easily to the heart.
Description
Isosorbide Dinitrate is a nitrate medication used for the prevention of angina pectoris (chest pain due to coronary artery disease). It works by relaxing vascular smooth muscles by stimulating cyclic-GMP. It decreases left ventricular pressure (preload) and arterial resistance (afterload), thereby reducing the heart's workload and oxygen demand.
Indications
- Prevention of angina pectoris (chest pain due to coronary artery disease)
Therapeutic class
Nitrates: Coronary vasodilators
Pharmacological class
Vasodilator (Nitrate)
Pharmacology
Isosorbide dinitrate relaxes vascular smooth muscles by stimulating cyclic-GMP. It dilates veins to promote peripheral pooling of blood and decreases venous return to the heart, reducing left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). Arteriolar relaxation reduces systemic vascular resistance, systolic arterial pressure, and mean arterial pressure (afterload).
Mechanism of action
Relaxes vascular smooth muscle by stimulating cyclic-GMP; reduces preload and afterload to decrease heart workload.
Dosage
Adult Dose (Oral):
- Angina Pectoris: 5-20 mg every 8-12 hours (initial); maintenance: 10-40 mg every 8-12 hours
Child Dose: Safety and efficacy not established
Administration
Place the tablet under the tongue or between the cheek and gum, and let it dissolve; do not chew, crush, or swallow; may be taken with or without food; better to take at a fixed time; take as needed (5-10 minutes before physical activities or at first sign of angina).
Missed dose
If you miss a dose, take it as soon as possible; if it is almost time for your next dose, skip the missed dose and go back to regular schedule; do not double the dose.
Side effects
Common Side Effects:
- Dizziness
- Headache
- Lightheadedness
- Nausea
- Changes to heart rate
- Flushing (warmth, redness, tingly feeling)
Precautions & warnings
Precautions:
- Isosorbide Dinitrate does not usually affect your ability to drive
- May cause dizziness or sleepiness; do not drive or do anything requiring concentration until you know how it affects you
- Avoid alcohol (may increase dizziness)
- Headaches usually go away after a few days; inform doctor if persists
- May develop tolerance over time; follow prescribed dosing schedule
- Do not take erectile dysfunction medications (sildenafil, tadalafil) as they may cause low blood pressure
Contraindications
Contraindications:
- Severe hypotension or anaemia
- Hypovolaemia
- Heart failure due to obstruction
- Raised intracranial pressure due to head trauma or cerebral haemorrhage
Drug interactions
Drug Interactions:
- Increased hypotensive effects with alcohol or vasodilators
- Marked orthostatic hypotension with calcium channel blockers
- Vasodilatory effect may be reduced with dihydroergotamine
- Significant hypotension with phosphodiesterase-5 inhibitors (Potentially Fatal)
Food interactions
Food Interactions: Consuming alcohol while taking Isosorbide Dinitrate may cause flushing, increased heart beat, nausea, thirst, chest pain and low blood pressure (Disulfiram reaction).
Use in pregnancy
Use in Pregnancy: May be unsafe; animal studies have shown harmful effects; doctor will weigh benefits and risks.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Probably safe; limited human data suggests drug does not represent significant risk to baby.
Pediatric use
Safety and efficacy in pediatric patients have not been established.
Geriatric use
No specific data for elderly; however caution advised.
Renal / hepatic impairment
Renal Impairment: Safe in kidney disease; no dose adjustment recommended; however inform doctor if you have underlying kidney disease.
Hepatic Impairment: Probably safe in liver disease; dose adjustment may not be needed; consult your doctor.
Overdose effects
Overdose: Severe hypotension, dizziness, headache, flushing, nausea, diarrhea; symptomatic treatment; gastric lavage; for hypotension, place patient in supine position and give IV fluids.
Storage conditions
Store in a cool and dry place, away from light & moisture; keep out of reach of children.
Chemical structure
Isosorbide Dinitrate