Approval status: February 2014.
Indication: Neurogenic orthostatic hypotension as it is helpful in treating orthostatic dizziness or lightheadedness, especially in adult patients with symptomatic neurogenic orthostatic hypotension caused by primary autonomic failure, like Parkinson’s disease, multiple system atrophy, etc. It is also helpful in people with dopamine beta hydroxylase deficiency.
Mechanism of action : it is a Norepinephrine precursor. Norepinephrine increases blood pressure through venous and peripheral arterial vasoconstriction. Therefore,peak droxidopa plasma concentrations are associated with increase in systolic and diastolic blood pressures.
Peak plasma concentrations: 1-4 hours.
Distribution: It is able to cross the blood brain barrier and it’s protein binding is upto 75%.
Metabolism: is mediated by catecholamine pathway and not through the CYP450 system.
Elimination: 75% of this drug is excreted in the urine, having a half life of 2.5 hours.
Dosing forms & strength: it is supplied in a form of a capsule. It is available in the strengths of 100mg, 200mg and 300mg. The dose for this drug is 100mg PO TID initially. It is titrated to symptomatic response, in increments of 100mg TID every 24-48 hours. It is not to be exceeded 600mg TID. The effectiveness beyond 2 weeks is uncertain and patients need to be monitored and evaluated periodically to determine whether Northera is providing benefit or not.
Side effects: following side effects were seen… headache, nausea, fatigue, hypertension.
BLACK BOX WARNING: The patient’s Supine blood pressure prior to and during treatment should be monitored. Elevating the head of the bed lessens the risk of supine hypertension.
Caution: care should be exercised while co administering droxidopa with other drugs that increase blood pressure.