Alirocumab: what it treats, how to take it, side effects
Last updated September 3, 2026.
Alirocumab (brand name Praluent) is the other PCSK9-inhibitor injection, lowering LDL cholesterol by roughly 50 to 60% beyond what statins achieve. Approved the same year as evolocumab (2015), its distinguishing features are a lower 75 mg starting dose with titration to 150 mg, and cardiovascular-outcome data from the ODYSSEY trial program.
What does it treat?
Established cardiovascular disease, reducing heart-attack, stroke, and unstable-angina risk, and primary hypercholesterolemia including heterozygous familial hypercholesterolemia (adults and children 8 and older), always alongside diet and maximally tolerated statin therapy. Same mechanism as its sibling: block PCSK9, keep more LDL receptors on liver cells, pull more LDL out of circulation.
How do you take it?
A self-given subcutaneous injection, typically 75 mg every 2 weeks, titrated to 150 mg every 2 weeks if LDL needs to come down further; a 300 mg every-4-weeks schedule exists for some. Refrigerate it, warm the pen or syringe to room temperature for 30 to 40 minutes before injecting (and never re-refrigerate after warming), and rotate between thigh, abdomen, and upper arm. Missed dose: within 7 days, inject and resume your schedule; past 7 days, skip and reset. Your LDL is rechecked a few weeks after any dose change.
Side effects to know
- Common: injection-site reactions (redness, itching, swelling, pain), flu-like symptoms, and muscle aches.
- Serious: hypersensitivity reactions, including rare vasculitis and angioedema requiring hospitalization; a serious allergic reaction ends the drug.
Who should not take it?
Anyone with a prior serious hypersensitivity reaction to alirocumab. Pregnancy and breastfeeding data are limited, so those are clinician decisions. As with its class, it is positioned for patients whose LDL remains above goal despite maximally tolerated statins, or with familial hypercholesterolemia, and prior authorization paperwork documenting that history is normal. It does not replace statins.
When is it an emergency?
Call 911 for facial or throat swelling, trouble breathing, or a severe spreading rash after an injection. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
How much will it lower my LDL?
Roughly 45 to 60% on top of your statin, depending on dose: the 75 mg start produces around 45 to 50%, and 150 mg pushes toward 60%. Your prescriber rechecks LDL a few weeks after starting and after any increase, and titrates against the number, not by feel.
Why start at 75 mg instead of the full dose?
Because many patients reach goal on the lower dose, and lower dose means lower cost and fewer site reactions. The label builds in the titration: LDL is checked after several weeks, and 150 mg every 2 weeks is there when 75 is not enough. Evolocumab's approach differs: fixed 140 mg every 2 weeks or 420 mg monthly.
Does it have outcome data, or just cholesterol numbers?
Real outcome data. The ODYSSEY OUTCOMES trial in post-heart-attack patients showed fewer major cardiovascular events and a mortality signal on alirocumab versus placebo on top of statins. It is one of the reasons guidelines give PCSK9 inhibitors a firm place rather than a hopeful one.
What if I miss an injection?
Within 7 days of the missed dose: inject as soon as you remember and continue your normal schedule. Beyond 7 days: skip it and restart the schedule from the next date. Do not double up, and tell your doctor if misses are becoming a pattern, since LDL control depends on the every-2-weeks rhythm.
Is it safe long-term?
Extension data now run several years: the side-effect pattern stays dominated by injection-site reactions, with no emerging liver, muscle, or cognitive toxicity signals, and very low LDL levels have not shown harm. Allergy is the one reaction that ends it, and it is rare.
How does the injection actually go?
Subcutaneous, into the thigh, abdomen, or upper arm, rotating sites. The pen is designed for self-use after one training session; the needle is hidden and the push takes seconds. Warm it 30 to 40 minutes out of the fridge first, because cold medication stings more. Most needle-anxious patients report it is far easier than they feared.