PCSK9 Inhibitor (Human Monoclonal Antibody) Pregnancy: Avoid — insufficient data; no known teratogenicity but discontinue if pregnancy discovered.

Alirocumab (PCSK9 Inhibitor — Post-ACS)

Brand names: Praluent

Adult dose

Dose: 75 mg SC every 2 weeks (start); may increase to 150 mg SC every 2 weeks if LDL-C not at target after 4–8 weeks. Alternative: 300 mg SC every 4 weeks (monthly dosing)

Route: Subcutaneous injection (autoinjector pen or prefilled syringe)

Frequency: Every 2 weeks (standard) or every 4 weeks (300 mg dose)

Max: 150 mg every 2 weeks; or 300 mg every 4 weeks

Inhibits PCSK9 (proprotein convertase subtilisin/kexin type 9) → prevents LDL receptor degradation → upregulation of LDL receptors → dramatic LDL-C reduction (40–70%). NICE TA394/TA895: alirocumab or evolocumab indicated when LDL-C not adequately controlled on maximally-tolerated statin ± ezetimibe. ODYSSEY OUTCOMES showed post-ACS mortality benefit.

Paediatric dose

Route:

Not licensed in paediatrics (evolocumab has paediatric indication for homozygous FH ≥10 years; alirocumab does not).

Dose adjustments

Renal

No dose adjustment required for mild-severe renal impairment.

Hepatic

No dose adjustment for mild-moderate hepatic impairment. Severe hepatic impairment: limited data.

Clinical pearls

ODYSSEY OUTCOMES trial (Schwartz et al. NEJM 2018): alirocumab vs placebo in recent ACS (1–12 months post-ACS) with LDL ≥1.8 mmol/L on statin — 15% relative risk reduction in primary endpoint (CV death, MI, stroke, unstable angina hospitalisation). Mortality benefit emerged in highest-risk subgroup (LDL ≥2.6 mmol/L, baseline LDL ≥3.2 mmol/L)
LDL target approach: ESC 2019/2021 dyslipidaemia guidelines recommend LDL target <1.4 mmol/L in very-high-risk patients (ACS, established CVD, FH). Alirocumab commonly added on top of high-intensity statin + ezetimibe when LDL remains above target — 'triple therapy' strategy
Cost-effectiveness: NICE TA394 (2016) restricted alirocumab to patients with primary non-familial hypercholesterolaemia or heterozygous FH who have not achieved adequate LDL reduction despite maximal statin + ezetimibe; TA895 (2023) updated criteria may broaden access post-ACS

Contraindications

Hypersensitivity to alirocumab or any excipient

Side effects

Injection site reactions (erythema, bruising, pain — most common adverse effect; rotate sites)
Nasopharyngitis and URI (common)
Back pain
Hypersensitivity reactions (angioedema, urticaria — rare but reported; MHRA warning)
Neurocognitive effects (concern raised — ODYSSEY OUTCOMES showed no signal)

Interactions

No clinically significant pharmacokinetic interactions — alirocumab is a monoclonal antibody, not metabolised by CYP enzymes
Statins (pharmacodynamic synergy — additive LDL reduction; intended combination)

Monitoring

Fasting LDL-C (at 4–8 weeks after starting or dose change)
Injection site for local reactions
Hypersensitivity signs (angioedema)
Adherence (SC injection technique — nurse training recommended initially)

Reference: BNFc; BNF 90; ODYSSEY OUTCOMES (Schwartz et al. NEJM 2018); NICE TA394/TA895; ESC Dyslipidaemia Guidelines 2019; MHRA SPC Praluent. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways