Adrenaline

Descriptions:
Adrenaline is a direct-acting sympathomimetic agent exerting its effect on alpha and beta-adrenoceptors. The overall effect of adrenaline depends on the dose, and may be complicated by the homeostatic reflex responses. In resuscitation procedures it is used to increase the efficacy of basic life support. It is a positive cardiac inotrope. Major effects are increased systolic blood pressure by arterioral and venous vasoconstriction (alpha1 effects), reduced diastolic pressure, tachycardia and hyperglycaemia. Adrenaline is rapid in onset and with short duration. After IV infusion the half-life is approximately 5-10 minutes. It is rapidly distributed to the heart, spleen, several glandular tissues and adrenergic nerves. Adrenaline is rapidly metabolised in the liver and tissues by oxidative de-amination and O-methylation followed by reduction or by conjugation with glucuronic acid or sulphate. Up to 90% of the IV dose is excreted in the urine as metabolites. It is approximately 50% bound to plasma proteins.

Dosage:

Cardiac arrest:

1. Intravenous injection: 1 mg injection repeated every 2-3 minutes as necessary.
2. Endothelial: 2-3 mg via an endothelial tube, repeated as necessary.
3. Intracardiac injection: 0.1 to 1 mg, direct into the atrium of the heart.
4. Intraspinal use: Usual dose is 0.2 to 0.4 mg added to anesthetic spinal fluid mixture (to prolong anesthetic action by limiting absorption).
Anaphylaxis, asthma or severe bronchospasm: Adult dose is 0.25 - 0.5 mg. It may be repeated at 5 minutes intervals until perfusion and respiratory status normalizes. In case of dose dilution: 1 mg of Adrenaline to be diluted in 9 ml Normal Saline.
Children: Intravenous injection: Initially 10 mcg/kg body weight, not to exceed 250 mcg. May be repeated every 3-5 minutes if necessary. Subsequent doses should be 100 mcg/kg.

Side Effects:

Anxiety, restlessness, dizziness, headache, palpitations, rapid pulse, tremors, weakness and coldness of the extremities may be reported even with small doses and especially when given in conjunction with local anaesthetics.