What is the recommended dosage for adrenaline administered intramuscularly?

The recommended dosage for adrenaline, when administered intramuscularly, typically is 0.5 mg for adult patients experiencing anaphylaxis. This dosage is aligned with clinical guidelines that emphasize the rapid response required in cases of severe allergic reactions. Administering 0.5 mg allows for an effective and immediate response to counteract the effects of anaphylaxis, such as bronchospasm and hypotension.

Adrenaline works by causing vasoconstriction, increasing heart rate, and relaxing bronchial smooth muscle, which together help to stabilize the patient's condition in emergencies. In children, the dosage is usually 0.01 mg/kg, but never exceeding the adult dose of 0.5 mg.

In contrast, the other dosages listed do not align with standard guidelines for intramuscular administration for emergency situations like anaphylaxis. For example, 0.1 mg is too low to be effective in most adult cases, while 1 mg and 2 mg would likely be considered excessive for intramuscular delivery in such situations, potentially leading to adverse effects. Therefore, the determination of 0.5 mg as the correct dosage reflects the optimal balance between efficacy and safety in emergency settings.