Usage
- Isoxsuprine is prescribed for the relief of symptoms associated with cerebrovascular insufficiency (poor blood flow to the brain) and peripheral vascular diseases, such as arteriosclerosis obliterans (hardening of the arteries), thromboangiitis obliterans (Buerger’s disease), and Raynaud’s disease (a condition affecting blood flow to the extremities). It is also used to arrest premature labor.
- Pharmacological Classification: Vasodilator, β-adrenergic receptor stimulator.
- Mechanism of Action: Isoxsuprine relaxes vascular and uterine smooth muscle, leading to vasodilation (widening of blood vessels). It decreases peripheral vascular resistance and increases muscle blood flow.
Alternate Names
- Isoxsuprine Hydrochloride
- Brand Names: Vasodilan, Isoxilan, Solvaprine
How It Works
- Pharmacodynamics: Isoxsuprine is a β2-adrenergic agonist and vasodilator. It causes vasodilation by direct relaxation of vascular smooth muscle and increases muscle blood flow. It may decrease blood pressure, increase heart rate, and increase cardiac output. It also relaxes uterine smooth muscle.
- Pharmacokinetics:
- Absorption: Well absorbed from the gastrointestinal tract.
- Metabolism: Partially conjugated in the body.
- Elimination: Primarily excreted in the urine, mainly as conjugates. Fecal excretion is negligible.
- Mode of Action: Isoxsuprine acts as a β2-adrenergic receptor agonist and also has direct effects on vascular smooth muscle. It increases intracellular cAMP, leading to smooth muscle relaxation and vasodilation.
- Elimination Pathways: Primarily renal excretion, mainly as conjugates.
Dosage
Standard Dosage
Adults:
- Cerebrovascular insufficiency and peripheral vascular diseases: 10 to 20 mg orally, three or four times daily.
- Premature labor: Initially, 200-500 mcg/min via IV infusion using a syringe pump. After premature labor is arrested, administer 10 mcg intramuscularly every 3-8 hours. Maximum treatment duration: 48 hours.
Children:
- Safety and effectiveness in pediatric patients have not been established.
Special Cases:
- Elderly Patients: Avoid use due to potential adverse effects and limited evidence of effectiveness.
- Patients with Renal Impairment: Dose adjustments may be necessary.
- Patients with Hepatic Dysfunction: Dose adjustments may be necessary.
- Patients with Comorbid Conditions: Use with caution in patients with hypotension (low blood pressure), heart disease, or severe anemia.
Clinical Use Cases
- Intubation: No specific dosage recommendations for intubation.
- Surgical Procedures: No specific dosage recommendations for surgical procedures.
- Mechanical Ventilation: No specific dosage recommendations for mechanical ventilation.
- Intensive Care Unit (ICU) Use: No specific dosage recommendations for ICU use.
- Emergency Situations: In emergency situations like premature labor, an IV infusion is used initially, followed by intramuscular injections.
Dosage Adjustments
- Dose modifications are based on patient response and tolerance. Renal and hepatic impairment may require dose reduction.
Side Effects
Common Side Effects:
- Dizziness
- Flushing
- Stomach upset
- Nausea
- Shaking or nervousness
- Tachycardia (rapid heart rate)
- Hypotension (low blood pressure)
- Chest pain
- Vomiting
Rare but Serious Side Effects:
- Severe rash
- Liver toxicity
- Maternal pulmonary edema (fluid in the lungs)
- Fetal tachycardia
Long-Term Effects:
- No specific information on long-term side effects is available.
Adverse Drug Reactions (ADR):
- Severe hypotension
- Liver toxicity
- Allergic reactions
Contraindications
- Recent arterial hemorrhage (bleeding from an artery)
- Immediately postpartum (after delivery)
Drug Interactions
- Other vasodilators and antihypertensive agents (may cause severe hypotension).
- Beta-blockers (may reduce isoxsuprine’s effects).
Pregnancy and Breastfeeding
- Pregnancy Safety Category: C (Risk cannot be ruled out).
- Fetal Risks: Fetal tachycardia, increased incidence of ileus (intestinal blockage) and respiratory distress syndrome.
- Breastfeeding: It is not known whether isoxsuprine passes into breast milk. Use with caution.
Drug Profile Summary
- Mechanism of Action: β2-adrenergic receptor stimulation and direct vasodilation.
- Side Effects: Dizziness, flushing, nausea, tachycardia, hypotension.
- Contraindications: Recent arterial hemorrhage, immediately postpartum.
- Drug Interactions: Other vasodilators, antihypertensive agents.
- Pregnancy & Breastfeeding: Category C, use with caution.
- Dosage: Varies depending on indication and patient factors. See detailed dosage section.
- Monitoring Parameters: Heart rate, blood pressure, liver function tests.
Popular Combinations
- No commonly recommended drug combinations with isoxsuprine are available.
Precautions
- Monitor for hypotension, tachycardia, and other side effects.
- Use with caution in elderly patients and those with hepatic or renal impairment.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Isoxsuprine?
A: The dosage varies depending on the condition being treated. For cerebrovascular insufficiency and peripheral vascular disease, the usual adult dose is 10-20 mg three or four times a day. For premature labor, the initial dose is 200-500 mcg/min via IV infusion, followed by 10 mcg intramuscularly every 3-8 hours.
Q2: What are the common side effects of Isoxsuprine?
A: Common side effects include dizziness, flushing, nausea, vomiting, tachycardia, and hypotension.
Q3: Is Isoxsuprine safe during pregnancy?
A: Isoxsuprine is Pregnancy Category C. It should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.
Q4: How does Isoxsuprine work?
A: It works by relaxing vascular and uterine smooth muscle, leading to vasodilation.
Q5: What are the contraindications for Isoxsuprine?
A: Isoxsuprine is contraindicated in patients with recent arterial hemorrhage and in the immediate postpartum period.
Q6: Does Isoxsuprine interact with other medications?
A: Yes, it can interact with other vasodilators and antihypertensive medications, potentially causing severe hypotension.
Q7: Can Isoxsuprine be used in children?
A: Safety and effectiveness in children have not been established.
Q8: What should patients be monitored for while taking Isoxsuprine?
A: Patients should be monitored for hypotension, tachycardia, and signs of liver toxicity.
Q9: What is the pharmacological classification of Isoxsuprine?
A: Isoxsuprine is classified as a vasodilator and a β-adrenergic receptor stimulator.
Q10: How is Isoxsuprine eliminated from the body?
A: Isoxsuprine is primarily excreted in the urine, mainly as conjugates.
