Drug Interactions between midodrine and Ritalin LA

MONITOR: The pressor effects of midodrine may be potentiated by the concomitant use of other agents that cause vasoconstriction, including sympathomimetics and ergot alkaloids. Midodrine is an alpha-adrenergic agonist and may cause marked elevation of supine arterial blood pressure, or supine hypertension. In clinical trials, systolic pressures of about 200 mmHg were observed overall in about 13.4% of patients given 10 mg of midodrine, the majority of whom also had relatively elevated pretreatment systolic blood pressures (mean 170 mmHg). There is no experience in patients with initial supine systolic pressure above 180 mmHg, as those patients were excluded from clinical trials. Sitting blood pressures were also elevated by midodrine therapy.

MANAGEMENT: Caution is advised if midodrine must be used in combination with other agents that can increase blood pressure. Supine and sitting blood pressures should be closely monitored. Supine hypertension can often be controlled by keeping the patient from being fully supine, for example, sleeping with the head of the bed elevated. Taking the last daily dose of midodrine 3 to 4 hours before bedtime may also help to minimize nighttime supine hypertension. Patients should be advised to contact their physician immediately if they experience symptoms of supine hypertension such as cardiac awareness, pounding in the ears, headache, and blurred vision. Midodrine should be discontinued if supine hypertension persists.