In Clinical

Follow this topic

Bookmark

Record learning outcomes

Peter Handley tells pharmacist Parveen that he is concerned about his partner’s low blood pressure and wonders if she should be on medication...

“My partner Susie has asked the GP about it but he just said it was a sign of good health. I know what he means, but Susie’s blood pressure is so low that she is literally falling over because of it. I’m starting to think she needs some medication.”

Answer

Hypotension is generally accepted as being a blood pressure reading of 90/60mmHg or lower. Most people who have it do not experience any symptoms, but because the blood flow to the brain may not be as good as it could be, it can on occasion cause problems, such as feeling lightheaded or dizzy, balance loss, blurred vision, confusion, nausea, palpitations and fainting.

Hypotension sufferers can try and reduce any symptoms they may be experiencing by:

• Staying well hydrated in order to maintain blood volume
• Limiting intake of alcohol and caffeine, as these can have a diuretic effect
• Standing up gradually rather than leaping up, particularly on waking in the morning
• Avoiding standing for long periods of time, or flexing feet in shoes while standing if this is unavoidable
• Increasing salt intake (within normal recommended limits)
• Taking warm rather than hot showers and baths
• Wearing compression stockings.

Postural hypotension is considered a separate condition and is defined as a fall in blood pressure of more than 20mmHg systolic or 10mmHg diastolic upon standing.

Hypotension is not usually treated with pharmacological measures, unless the individual feels very unwell or is thought to be at risk because of it. There is some evidence supporting the use of the mineralocorticoid fludricortisone (thought to act by reducing fluid and salt loss), ephedrine or a direct acting sympathomimetic, but none of these agents are licensed for this indication.

The bigger picture

While hypotension is easy to diagnose, it is considerably trickier to work out the cause, particularly if the patient has no other symptoms. Some of the conditions that can be responsible for hypotension include cardiac problems such as arrhythmias and heart failure, nervous system disorders such as diabetes and Parkinson’s disease, the endocrine disorder Addison’s disease, and certain medicines.

There are also a number of acute conditions that can cause hypotension; for example, dehydration (including that due to blood or fluid loss after an injury or burn), anaphylaxis and a severe infection, although it is generally obvious that someone is suffering from one of these.

Extend your learning

Are you aware of the drug classes that can cause hypotension as a side-effect? Go to the online British National Formulary (free registration required) and type hypotension into the search facility to get an idea.