Midodrine

Dizzy on standing: what midodrine is for

Stand up fast and some people go grey at the edges of their vision, with a swimming head and unsteady legs. The cause is orthostatic hypotension, a fall in blood pressure within seconds of getting to your feet, as blood pools in the legs. Midodrine is for those whose drops get in the way of daily life, at the stove or in a queue; a low reading that never causes symptoms is not what it treats. The body converts the tablet into its active form, which stimulates alpha-1 receptors in the walls of small blood vessels. The vessels narrow and pressure rises.

Fitting three tablets into a waking day

Someone who is up at seven and in bed at eleven has a working window that runs from morning until about seven in the evening. Three tablets fit inside it, three or more hours apart: one on getting up, one at midday, one in the late afternoon. Nothing goes in after that. Midodrine raises pressure lying down as well as standing, so a dose still working at bedtime pushes the night-time reading up. Plates and mealtimes make no difference.

The scalp tingling is normal

Soon after a dose many people notice the scalp prickling or itching, goosebumps on the arms, or a passing chill. Headache and needing the toilet more often come up too. The scalp is where it shows because the small vessels there, and the tiny muscles that raise each hair, carry the receptors the tablet stimulates. Mostly it is mild.

When pressure rises too far lying down

The effect to take seriously is supine hypertension, blood pressure that climbs too high when you lie on your back. It is why no tablet is taken near bedtime, and why many people sleep with the head of the bed raised, which keeps the overnight rise smaller. A severe headache, blurred vision, pounding in the ears or a heartbeat you can feel strongly after a dose means pressure has gone too high and needs urgent attention.

Gutron, Midodrine and what to keep away from them

Two tablets are sold, both in heart and blood pressure. Gutron is 5mg. Midodrine is 2.5mg, the smallest size made, where treatment often starts before being stepped up with more than one tablet at a time.

Midodrine is not used by people with an adrenal tumour near the kidney (phaeochromocytoma), an overactive thyroid, trouble emptying the bladder, or heart or kidney disease. Decongestants and cold remedies built on pseudoephedrine, phenylephrine or phenylpropanolamine narrow vessels in the same way and can push pressure too far alongside it. Cimetidine, a heartburn medicine, and dihydroergotamine (DHE), a migraine treatment, interact with it as well.