Isoprenalina Cloridrato Galenica Senese (Isoprenaline Hydrochloride)

Isoprenaline acts on the beta‑adrenergic system to treat conditions characterized by low heart rate or bronchoconstriction.

• Bradycardia: raises heart rate to maintain adequate cardiac output.
• Heart block: improves atrioventricular conduction and heart rhythm.
• Cardiogenic shock: supports myocardial contractility and systemic perfusion.
• Asthma: relaxes bronchial smooth muscle to relieve airway obstruction.
• Bronchospasm: provides rapid bronchodilation during acute episodes.

• Isoprenaline Hydrochloride binds to and activates both beta‑1 and beta‑2 adrenergic receptors. Stimulation of beta‑1 receptors in the heart increases cyclic AMP, leading to enhanced calcium influx, faster depolarization, and stronger myocardial contraction. Activation of beta‑2 receptors in bronchial smooth muscle causes relaxation via cyclic AMP‑mediated pathways, resulting in bronchodilation.

Isoprenaline may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Tachycardia: rapid increase in heart rate.
• Palpitations: awareness of heart beating.
• Headache: mild to moderate intensity.
• Tremor: fine muscle shaking.
• Nausea: occasional gastrointestinal upset.
• Anxiety: feelings of nervousness or restlessness.

Serious or Rare Side Effects

• Arrhythmias: potentially life‑threatening irregular heart rhythms.
• Myocardial ischemia: reduced blood flow to heart muscle.
• Severe hypertension: dangerous elevation of blood pressure.
• Pulmonary edema: fluid accumulation in lungs.
• Anaphylactic reaction: severe allergic response.
• Severe bronchospasm: paradoxical worsening of airway constriction.

Use of Isoprenaline requires careful clinical monitoring and consideration of patient‑specific factors.

• Cardiovascular monitoring: continuously observe heart rate and blood pressure during administration.
• Ischemic heart disease: avoid or use with caution as increased myocardial demand may precipitate angina.
• Uncontrolled hypertension: contraindicated because it can exacerbate high blood pressure.
• Electrolyte disturbances: correct hypokalemia or other imbalances before use.
• Pregnancy and lactation: safety not established; prescribe only if potential benefit outweighs risk.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze.

Isoprenaline can interact with several drug classes, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Beta‑blockers: antagonize beta‑adrenergic stimulation, reducing therapeutic effect.
• Non‑selective beta‑blockers: block both beta‑1 and beta‑2 receptors, negating action.
• Class IA antiarrhythmics (e.g., quinidine): increase risk of pro‑arrhythmic events.
• Tricyclic antidepressants: may potentiate tachycardia and hypertension.
• Sympathomimetic amines (e.g., epinephrine): additive cardiovascular stimulation can cause severe hypertension.

Moderate Interactions (Monitor Closely)

• Diuretics: may cause electrolyte shifts that predispose to arrhythmias.
• Digitalis glycosides: combined use can increase risk of cardiac arrhythmias.
• Theophylline: additive bronchodilator effect may lead to excessive stimulation.
• CYP2D6 inhibitors: may modestly affect metabolism, requiring observation.