midodrine hydrochloride at a glance
Medicine class
Peripheral alpha-1 adrenergic agonist prodrug
Licensed use
Severe orthostatic hypotension due to autonomic dysfunction in adults
Administration
Swallow with water; it may be taken with food
Important timing point
Avoid taking it close to bedtime because blood pressure can become too high while lying down
What is midodrine hydrochloride used for?
The selected product is licensed for a specific form of severe low blood pressure. Some specialist services also use midodrine outside its licence.
Licensed: severe orthostatic hypotension caused by autonomic dysfunction in adults, after corrective factors have been excluded and other treatments are inadequate.
Non-licensed contexts: specialist NHS services may use midodrine for postural orthostatic tachycardia syndrome or vasovagal syncope.
How does midodrine hydrochloride work?
Midodrine is converted to the active substance desglymidodrine. This selectively stimulates peripheral alpha-1 receptors, narrowing veins and arteries, reducing venous pooling and increasing vascular resistance and blood pressure. It has no beta-adrenergic activity.
midodrine hydrochloride preparations and strengths
Tablet
Route: Oral
Strengths: 2.5 mg, 5 mg, 10 mg
How to take midodrine hydrochloride
Take midodrine exactly as prescribed and follow the timing given by the clinical team.
Swallow the tablet with water.
It may be taken with food.
Avoid taking it late in the evening or close to bedtime because of the risk of high blood pressure while lying down.
The selected tablet's score line is for easier swallowing, not for dividing it into equal portions.
midodrine hydrochloride side effects
Common or expected effects
- Goosebumps
- Itchy scalp or skin
- Pain or difficulty when passing urine
- Pins and needles, including on the scalp
- Headache
- Nausea or indigestion
- Flushing, chills or rash
- High blood pressure while lying down
Get urgent medical advice
- Chest pain, shortness of breath, marked palpitations, severe headache or blurred vision suggesting excessive blood pressure
- A very slow heartbeat, faintness or collapse
- Inability to pass urine
- Rapid heartbeat or significant palpitations
- Possible liver problems, such as jaundice or dark urine
midodrine hydrochloride in pregnancy
Human pregnancy data are unavailable, and animal studies found reproductive toxicity at maternally toxic exposures. The selected product is not recommended during pregnancy or for someone who could become pregnant and is not using contraception; pregnancy or plans for pregnancy should be discussed with the prescriber.
midodrine hydrochloride while breastfeeding
It is unknown whether midodrine or its metabolites enter human milk, and risk to a breastfed infant cannot be excluded. The selected product should not be used during breastfeeding; specialist or prescriber review is needed if treatment is being considered.
midodrine hydrochloride interactions
Midodrine can interact with medicines affecting blood pressure, heart rate or alpha-adrenergic activity. Prescription, non-prescription and herbal products should be reviewed.
Sympathomimetics and other vasoconstrictors
The combination may cause a pronounced rise in blood pressure and should generally be avoided.
Tricyclic antidepressants, monoamine oxidase inhibitors, antihistamines and thyroid hormones
These may enhance vasoconstriction and increase blood pressure.
Alpha blockers such as prazosin or phentolamine
These can oppose and reduce midodrine's effect.
Common questions about midodrine hydrochloride
Answers are fully visible for fast scanning and source review.
What is midodrine hydrochloride used for?
It is licensed for severe orthostatic hypotension caused by autonomic dysfunction in adults when reversible factors have been excluded and other treatments are inadequate.
Does midodrine hydrochloride raise blood pressure?
Yes. Its active metabolite narrows peripheral blood vessels, reducing venous pooling and raising blood pressure.
Why should midodrine hydrochloride not be taken near bedtime?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.