An old blood-pressure medicine, also known from genetic testing
Debrisoquine
An old, now-obsolete blood-pressure medicine, also famous in genetic research into how people process drugs.
What is Debrisoquine?
Debrisoquine is an older medicine that was once used to lower high blood pressure. It belongs to a group called adrenergic neurone blockers, which work by reducing the nerve signals that tighten blood vessels. Its defining problem is severe postural hypotension, a sharp fall in blood pressure on standing up that causes dizziness or fainting. Because of this and the availability of better treatments, it is now obsolete and no longer used. It is also famous in pharmacogenetics, the study of how people's genes affect the way they handle medicines, because it helped reveal that people differ in how quickly they break drugs down.
Education and reference only. This is a plain-language guide to Debrisoquine — 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
Debrisoquine is a medicine from an older class called adrenergic neurone blockers, which were once used to treat high blood pressure. They lower blood pressure by interfering with the nerves that release the body's natural chemicals that tighten blood vessels. Debrisoquine is no longer used as a treatment, having been replaced by modern blood-pressure medicines that are far better tolerated. It has a second claim to fame outside the clinic: in pharmacogenetics, the study of how genes affect the way people respond to medicines, it became a classic example showing that people vary in how quickly they break down certain drugs, which helped shape modern understanding of personalised medicine.
How it works
Debrisoquine works by acting on the nerve endings that normally release noradrenaline, one of the body's natural chemicals that tightens blood vessels and helps keep blood pressure up. By blocking the release of this chemical, it relaxes blood vessels and lowers blood pressure. The trouble is that this same action strongly affects the reflexes that keep blood pressure steady when you stand up, so blood pressure can fall sharply on standing, causing dizziness or fainting. In genetic research, debrisoquine was used as a marker drug because the speed at which different people break it down varies with their genes, which revealed important differences between people in handling medicines.
Company & origin
Originated / developed by: Generic (no longer used).
An older blood-pressure-lowering medicine, an adrenergic neurone blocker, now obsolete but also well known in pharmacogenetics for showing how people differ in handling medicines.
Practical use
How to take Debrisoquine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is no longer used as a treatment, so it is not something prescribed or taken today.
- When it was used, the main caution was rising slowly from lying or sitting to standing to avoid dizziness.
- It would have been used only under medical supervision with blood pressure checked in different positions.
- Modern, better-tolerated medicines are now used instead for high blood pressure.
- Any mention of it today is usually in the context of genetic research rather than treatment.
Weighing it up
Advantages & disadvantages of Debrisoquine
Advantages
- Was able to lower high blood pressure at a time when fewer treatments were available.
- Worked through a different mechanism from many later blood-pressure medicines.
- Became scientifically valuable as a classic example in pharmacogenetics.
Disadvantages
- Causes severe postural hypotension, with a sharp fall in blood pressure on standing.
- Poorly tolerated compared with modern blood-pressure medicines.
- Now obsolete and no longer used as a treatment.
Practical use
Good to know
The most important practical point about debrisoquine is severe postural hypotension: because of how it works, blood pressure can drop sharply when moving from lying or sitting to standing, causing dizziness, light-headedness or fainting, which made it difficult and unpleasant to use. This effect, along with the arrival of modern, better-tolerated blood-pressure medicines, is why it is now obsolete and no longer prescribed. Its lasting importance is mainly historical and scientific: in pharmacogenetics it became a classic example showing that people differ, partly because of their genes, in how quickly they break down medicines, which helped lay the groundwork for today's understanding of why the same medicine can affect different people differently. Most people will only ever encounter debrisoquine as a name in this research context rather than as a treatment.
Who should not take it / use with caution
- It is no longer used as a treatment, so it is not prescribed for high blood pressure today.
- When used, it was unsuitable for people prone to fainting or with poor control of blood pressure on standing.
- Modern, safer and better-tolerated medicines are used instead.
Monitoring
- When used, blood pressure was checked lying, sitting and standing to detect postural falls.
- Watching for dizziness or fainting on standing.
- In research, the rate at which people broke it down was used as a genetic marker.
Side effects
- Severe postural hypotension, a sharp fall in blood pressure on standing, causing dizziness or fainting.
- Light-headedness and tiredness linked to low blood pressure.
- Other effects linked to its action on the body's nerve signals.
Key interactions
- Its blood-pressure-lowering effect could add to that of other medicines that lower blood pressure.
- Its effects could be altered by medicines acting on the body's adrenaline-like nerve system.
- These interactions are now of historical interest, as the medicine is no longer used.
Available as: Tablets taken by mouth (historical).
Answers
Debrisoquine: frequently asked questions
What was debrisoquine used for?
It was an older medicine used to lower high blood pressure, belonging to a group called adrenergic neurone blockers; it is now obsolete and no longer used.
Why is it no longer used?
It causes severe postural hypotension, a sharp fall in blood pressure on standing, and modern, far better-tolerated blood-pressure medicines are now available instead.
Why is it famous in genetics?
In pharmacogenetics it became a classic example showing that people differ, partly because of their genes, in how quickly they break down medicines, shaping ideas about personalised medicine.
What is postural hypotension?
It is a drop in blood pressure when moving from lying or sitting to standing, which can cause dizziness, light-headedness or fainting, and was the main problem with this medicine.
Could I be prescribed it today?
No. Debrisoquine is obsolete and no longer prescribed; high blood pressure is now treated with safer, better-tolerated medicines.
Authoritative sources
- BNF
- NICE CKS
Building a medicines information resource?
We create evidence-led, dose-free drug and formulary references for teams.