Alpha-1 Antitrypsin Replacement (Enzyme Supplement)

Alpha-1 Proteinase Inhibitor

Brand names: Respreeza (human alpha-1-antitrypsin)

Adult dose

Dose: 60 mg/kg once weekly

Route: Intravenous infusion

Frequency: Once weekly

Clinical pearls

Indicated for augmentation therapy in emphysema due to severe alpha-1 antitrypsin deficiency (AATD)
Diagnosis: alpha-1 antitrypsin level <11 µmol/L with emphysema and compatible genotype (ZZ, SZ, compound heterozygous)
RAPID extension trial showed slowing of CT-measured emphysema progression
NICE does not routinely commission — NHS England prior approval required; assessed individually
Optimise standard COPD therapy (bronchodilators, smoking cessation, vaccination) alongside
Best evidence in current/ex-smokers with established emphysema and FEV1 25–80% predicted

Contraindications

IgA deficiency with anti-IgA antibodies (risk of severe hypersensitivity — Respreeza contains trace IgA)
Severe hypersensitivity to human plasma-derived products

Side effects

Infusion-related reactions (headache, dizziness, pyrexia)
Hypersensitivity/anaphylaxis (rare)
Nasopharyngitis
Theoretical risk of transmissible agents (human-derived product — manufacturing includes viral inactivation steps)

Interactions

No significant pharmacokinetic interactions
Avoid concomitant i.v. administration through same line as other agents

Monitoring

Alpha-1 antitrypsin trough serum levels (target >11 µmol/L pre-infusion)
Lung function (FEV1) every 6 months
CT lung densitometry periodically
Infusion reactions
Hepatic function (AATD also causes liver disease)

Reference: BNF; NICE EAMS (Respreeza assessment); RAPID trial (Lancet 2015); Alpha-1 Foundation guidelines; ERS Statement on AATD (Eur Respir J 2017); https://bnf.nice.org.uk/drugs/alpha-1-proteinase-inhibitor/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways