Cardiovascular
PCSK9 inhibitors
Injectable cholesterol-lowering antibodies — Powerful injectable drugs that lower LDL cholesterol when statins are not enough.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
PCSK9 inhibitors are injectable drugs that lower LDL ("bad") cholesterol substantially. They are used, under specialist guidance, when statins and ezetimibe have not brought cholesterol low enough in high-risk patients.
How it works
The liver clears LDL cholesterol from the blood using LDL receptors. A protein called PCSK9 destroys those receptors; blocking PCSK9 lets the liver keep more receptors and clear far more LDL from the blood, producing a large fall in cholesterol.
In practice
In practice PCSK9 inhibitors are reserved, specialist-initiated injectable treatments for people whose LDL cholesterol stays high despite maximum tolerated statin and ezetimibe — particularly those at very high cardiovascular risk or with familial hypercholesterolaemia. Given by a self-administered injection every few weeks, they produce a large further drop in LDL cholesterol on top of existing treatment and reduce cardiovascular events. They are notably well tolerated, the commonest issue being mild injection-site reactions, which is part of their appeal in statin-intolerant patients (though they are usually added to, rather than replacing, a statin where one can be taken). Access is governed by eligibility thresholds, so they are used selectively rather than broadly.
Examples
Practical use
How to take it & use it well
- Alirocumab and evolocumab are given as an injection under the skin, usually into the tummy, thigh or upper arm, on a regular schedule set by your specialist.
- Inclisiran is also a subcutaneous injection but is given by a healthcare professional much less often after the first doses.
- If you self-inject alirocumab or evolocumab, follow the training your team gives, let the pen reach room temperature first, and rotate the site each time.
- Store the pens or syringes in the fridge as instructed, protect them from light, and do not use them if frozen or past their date.
- Keep taking any statin or other lipid medicine your team has prescribed, as these injections are usually added on top.
- Report any marked injection-site reaction, persistent flu-like symptoms or allergic reaction to your team.
Common uses
- High LDL cholesterol despite maximal statin/ezetimibe
- Familial hypercholesterolaemia
- Very high cardiovascular risk needing further LDL reduction
Monitoring
- LDL-cholesterol response
- Injection-site tolerability
- Continued eligibility and adherence
Weighing it up
Advantages & disadvantages
Advantages
- Strongly lower harmful LDL cholesterol, often when statins alone are not enough or are not tolerated.
- Can further reduce the risk of heart attacks and strokes in high-risk people on top of other treatment.
- Given as injections spaced days, weeks or even months apart, which suits people who struggle with daily tablets.
- Generally well tolerated, with relatively few side effects for most people.
Disadvantages
- Are given by injection rather than as tablets, which some people dislike.
- Are specialist medicines started under defined criteria, so not everyone qualifies.
- Can cause injection-site reactions such as redness, itching or soreness.
- May occasionally cause flu-like symptoms or, rarely, allergic reactions.
Key safety principles
What to watch for
- Generally very well tolerated — mainly mild injection-site reactions.
- Specialist-initiated with eligibility thresholds; usually added to existing therapy.
- Given by injection every few weeks (or less often for inclisiran).
Key interactions
What to avoid or check alongside
- These injections have few known interactions with other medicines, which is one of their advantages.
- They are usually combined safely with statins and ezetimibe, and the combined cholesterol-lowering effect is intended.
- There is no major interaction with common heart or blood-pressure medicines at usual use.
- As with any treatment, tell your specialist about all your medicines and supplements so your overall plan is reviewed.
- Report any new or unusual symptoms after starting, as experience guides safe long-term use.
Patient & carer advice
- You or a nurse will be shown how to give the injection
- It is usually added to your other cholesterol treatment
- Keep up the lifestyle measures that protect your heart
Use with
Related clinical calculators
Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
PCSK9 inhibitors: frequently asked questions
How are PCSK9 inhibitors given?
Alirocumab and evolocumab are injections under the skin given regularly, which patients can often do themselves after training. Inclisiran is also a skin injection but is given by a professional much less frequently.
Who can have these medicines?
They are specialist treatments started under defined NHS criteria, usually for people with very high cholesterol or high cardiovascular risk who are not controlled by, or cannot tolerate, other lipid medicines.
Do I stop my statin when I start a PCSK9 inhibitor?
Usually no. These injections are normally added on top of a statin or other lipid medicines to lower cholesterol further. Only change your other medicines if your specialist tells you to.
Are PCSK9 inhibitors well tolerated?
For most people, yes. The commonest issues are mild injection-site reactions such as redness or soreness, and occasionally flu-like symptoms. Serious reactions are uncommon but should be reported.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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