US patients with neurogenic orthostatic hypotension (NOH) have gained access to a new treatment option after regulators finally issued an approval for Chelsea Therapeutics' Northera (droxidopa).

The US Food and Drug Administration (FDA) has now given the all clear for the use of Northera to help prevent a sometimes debilitating drop in blood pressure and fainting episodes in patients with NOH.

NOH is a chronic neurogenic disorder caused by a deficient release of norepinephrine, which can give rise to symptoms such as dizziness, lightheadedness, blurred vision, fatigue, poor concentration and fainting episodes on standing up, often severely limiting a person's ability to perform routine daily activities.

Last month, FDA advisors voted 16-1 to recommend a green light for Northera, sending its stock up 120% in the immediate aftermath, on the back of clinical trials showing a decrease in dizziness, lightheadedness and feeling faint in patients taking the drug versus those taking a placebo. 

Northera carries a boxed warning on the risk of increased blood pressure while lying down (supine hypertension), a common problem that affects people with primary autonomic failure and can cause stroke, and so patients must sleep with their heads and upper bodies elevated.

News of the approval will be particularly sweet for Chelsea given that, in early 2012, the FDA rejected the Orphan drug, asking Chelsea for more data on its filing despite an advisory committee having voted 7-4 in favour of its approval.

Around 300,000 people in the US and Europe are thought to suffer fro the condition, and analysts at Deutsche Bank reportedly believe peak sales in the US will be around the $450 million mark.