A little about atropine

Atropine continues to be the first line medication used for acute symptomatic bradycardia in adults. Before administering atropine, it is important to assess whether the patient's symptoms are caused by the bradycardia, or, potentially the bradycardia is being caused by another issue, such as hypothyroidism, myocarditis, or medications. Generally, IV atropine in the recommended dosages (2010 guidelines dose is 0.5mg IV, repeatable every 3-5 minutes up to 3mg total) improves heart rate and alleviates symptoms associated with bradycardia. It is important to note, however, that atropine will generally be ineffective in 2nd degree type 2 (Mobitz 2) or third degree heart block, or in heart transplant patients. These patients are better treated with b-adrenergic drugs (low dose dopamine or epinephrine) or trans-cutaneous pacing. Be aware that small doses of atropine (smaller than 0.5mg IV) can have a paradoxical effect, causing a further drop in heart rate. Atropine has been removed from the pulseless arrests algorithms, as it was not found to be beneficial in these cases.