| Emergency drugs: adrenaline |
In addition to adrenaline's inotropic and chronotropic effects it causes bronchodilatation via its effects on beta2 receptors in bronchial smooth muscle. It also has mast cell stabilisation effects. These effects may reverse laryngeal oedema and bronchospasm.
Adrenaline may be nebulised using the 1 mg/mL ampoules. A 1% solution (10 mg/mL) is used by some centres, but this is not a commercially available product. Nebulised adrenaline has an onset of action within one to five minutes and a duration of one to three hours.
Adrenaline is available in an auto-injector preparation (Epi-Pen) in two dose sizes for prehospital treatment of anaphylaxis. These products contain 0.3 mg/dose for adults and children over 20 kg and 0.15 mg/dose for children between 10 to 20 kg. Doses are designed for intramuscular administration. The duration of action of such injections is only ten to twenty minutes; therefore it is essential that patients understand that they must seek emergency medical care as soon as possible after a dose has been administered.
Adrenaline doses are expressed in a number of ways. This increases the potential for administration errors. See Table 14.54 below.
Adverse effects of nebulised and intramuscular adrenaline are generally short-lived. They include tachycardia, hypertension and agitation.
See also Sympathomimetic drugs.
Adrenaline dose terminology (Table 14.54)
| Percent | Ratio | Concentration |
| 0.01% | 1 in 10 000 | 1 mg in 10 mL |
| 0.1% (most commonly available) | 1 in 1000 | 1 mg/mL |
| 1% | 1 in 100 | 10 mg/mL |
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