A medicine that raises low blood pressure
Midodrine
A medicine that raises blood pressure in people with severe orthostatic (standing) hypotension.
What is Midodrine?
Midodrine is different from most medicines on this page: instead of lowering blood pressure, it raises it. It is used for severe orthostatic hypotension, where blood pressure drops sharply on standing and causes dizziness or fainting. It works by tightening the blood vessels so blood pressure is better maintained when upright. Because it can also raise blood pressure when lying down (supine hypertension), you should not lie flat soon after a dose, and the last dose of the day is taken well before bedtime.
Education and reference only. This is a plain-language guide to Midodrine — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Midodrine is a vasopressor, a medicine that tightens the blood vessels to raise blood pressure. It is used for severe orthostatic hypotension, a condition where blood pressure falls too much when a person stands up, causing dizziness, light-headedness or fainting. By keeping the blood vessels firmer, midodrine helps maintain blood pressure when upright. It is taken by mouth as a tablet, usually during the daytime, and is reserved for cases where simpler measures have not worked.
How it works
Midodrine is changed in the body into an active substance that acts on the blood vessels, signalling the muscle in their walls to tighten. This narrowing raises the pressure inside the vessels, so blood pressure is better maintained, especially when standing. Because it raises blood pressure generally, it can also push blood pressure up too high when you lie down, which is why it is timed to the daytime and the last dose is taken well before lying down for the night.
Company & origin
Originated / developed by: Generic (long-established).
A medicine used in the UK to raise blood pressure in people with severe drops in blood pressure on standing.
Practical use
How to take Midodrine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it during the daytime as prescribed, usually spaced out across the day.
- Do not lie flat for a while after a dose, to reduce the risk of blood pressure rising too high when lying down.
- Take the last dose of the day at least four hours before you go to bed, so it has worn off before you lie down.
- Take a dose before activities that make you feel faint, such as standing for long periods, if advised.
- Tell your prescriber about pounding headache, blurred vision or a thumping heartbeat when lying down.
- Do not use it to treat ordinary tiredness or low energy; it is only for diagnosed low blood pressure on standing.
Weighing it up
Advantages & disadvantages of Midodrine
Advantages
- Raises blood pressure to reduce dizziness and fainting in severe orthostatic hypotension.
- Can make standing and daily activities more manageable when simpler measures have not worked.
- Taken by mouth and timed to the daytime to fit around being upright.
Disadvantages
- Can raise blood pressure too high when lying down (supine hypertension).
- Must be timed carefully to the daytime, avoiding doses close to lying down or bedtime.
- Can cause tingling of the scalp, goosebumps and an urgent need to pass urine.
Practical use
Good to know
It is important to understand that midodrine does the opposite of most blood pressure tablets: it raises blood pressure to help people whose pressure drops too much on standing. The key safety point is supine hypertension, meaning blood pressure that rises too high when lying flat. To avoid this, you should not lie down soon after taking a dose, you should take it while up and about during the day, and the last dose should be well before bedtime. Doses are taken at intervals through the day rather than at night. Tell your prescriber about a pounding headache, blurred vision or a thumping heartbeat when lying down, which can signal blood pressure that is too high.
Who should not take it / use with caution
- People with severe heart disease, very high blood pressure or certain overactive thyroid problems should not take it.
- It is avoided in people with serious kidney problems or difficulty passing urine.
- Used only with care in those who spend much of the day lying down, because of the risk of high blood pressure when supine.
Monitoring
- Blood pressure checks both standing and lying down, to confirm benefit and watch for supine hypertension.
- Reviewing dose timing to keep doses to the daytime and away from bedtime.
- Checking for difficulty passing urine and other side effects.
Side effects
- Tingling or itching of the scalp, goosebumps and chills.
- An urgent or more frequent need to pass urine, or difficulty passing urine.
- High blood pressure when lying down, sometimes with headache or a thumping heartbeat.
Key interactions
- Can cause blood pressure to rise too high if combined with other medicines that raise blood pressure.
- Care is needed with medicines that slow the heart, as together they can affect heart rate.
- Other medicines and remedies that raise blood pressure, including some cold remedies, can add to its effect.
Available as: Tablets taken by mouth.
Answers
Midodrine: frequently asked questions
Does midodrine raise or lower blood pressure?
It raises blood pressure; it is used for severe orthostatic hypotension, where blood pressure drops too much on standing and causes dizziness or fainting.
Why must I not lie down after a dose?
Midodrine can push blood pressure too high when you lie flat (supine hypertension), so you should stay upright for a while after each dose.
When should I take the last dose?
Take the last dose at least four hours before bedtime, not in the evening, so it has worn off before you lie down — this avoids raising your blood pressure while you sleep.
What should I report to my prescriber?
Tell them about a pounding headache, blurred vision or a thumping heartbeat when lying down, as these can signal blood pressure that is too high.
Can I take it for general tiredness?
No, it is only for diagnosed severe low blood pressure on standing and should not be used to treat ordinary tiredness or low energy.
Authoritative sources
- BNF
- NICE CKS
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