Escalating the dose and downgrading the rhythm: the combination of prescribed and non-prescribed medications resulting in an abnormal heart rhythm

Older patients often have multiple medical issues which predisposes them to complications of polypharmacy and medication interactions. We present a case of an 89-year-old female who presented to the emergency department after a fall. An electrocardiogram (ECG) showed a junctional bradycardia with a ventricular rate of 50 beats per minute (BPM). Her magnesium was 3.5 mg/dl (1.7–2.3 mg/dl). She had recently increased her milk of magnesia use for constipation. Pertinent other medications included verapamil 280 mg daily. On admission 2 grams of calcium gluconate IV were administered and the verapamil was held. An ECG the next morning showed sinus rhythm with a ventricular rate of 76 BPM.