Case report: severe myoclonus associated with oral midodrine treatment for hypotension.

RATIONALE

Midodrine is widely used in the treatment of hypotensive states, there have been no reports of myoclonus associated with midodrine use in hypotension with chronic kidney disease.

PATIENT CONCERNS

We report a 58-year-old female patient with chronic kidney disease (CKD) presenting with involuntary tremor 2 h after taking midodrine, which became more frequent after 6 h. Brain CT and neurological examination did not yield findings of note. Blood chemistry showed serum albumin of 3.1 g/L, ALT of 19 U/L, AST of 22 U/L, SCr of 273.9 μmol/L, K of 2.94 mmol/L, Ca of 1.63 mmol/L, and Mg of 0.46 mmol/L. Her BP was maintained at 83-110/56-75 mmHg. Her urine volume was 600-1000 mL/d, and her heart rate was within a range of 90-100 beats/min.

DIAGNOSIS

Chronic kidney disease (CKD), hypotension, metabolic acidosis, hypocalcemia, hypokalemia, and hypomagnesemia.

INTERVENTIONS

Midodrine treatment was stopped and the patient was treated with intravascular rehydration and furosemide. Myoclonus ceased one day after midodrine withdrawal.

LESSONS

Oral midodrine is widely used in the treatment of orthostatic hypotension, recurrent reflex syncope and dialysis-associated hypotension and the adverse effects are mostly mild. However, clinicians should be alert for midodrine-induced myoclonus, especially in patients with CKD.