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a1-Proteinase Inhibitor

Class: Respiratory Tract Agents, Miscellaneous
VA Class: RE900
Brands: Aralast, Prolastin, Zemaira

Medically reviewed by Last updated on March 23, 2020.


A naturally occurring serine protease inhibitor.1 2 3 11 15

Uses for a1-Proteinase Inhibitor

Congenital α1-Proteinase Inhibitor Deficiency

Replacement therapy in patients with congenital α1-proteinase inhibitor (also called α1-antitrypsin) deficiency and clinically evident emphysema.1 2 3 7 8 11 15

Not indicated as therapy for patients with lung disease in whom congenital α1-proteinase inhibitor deficiency has not been established.1 3 11

The American Thoracic Society and the European Respiratory Society (ATS/ERS) state that α1-proteinase inhibitor therapy does not confer benefit in, and is not recommended for, patients who have α1-proteinase-associated liver disease.a

a1-Proteinase Inhibitor Dosage and Administration


IV Administration

Administer by IV infusion.1 3 11

Administer IV infusions of Zemaira through an IV line using an administration set that contains an inline filter (pore size 5 µm).b

Monitor infusion rate and clinical status (e.g., vital signs, infusion-related reactions) of the patient continuously throughout the infusion.1 11

Administer with caution; percutaneous puncture with a needle contaminated with blood may transmit infectious agents.3 15 (See Risk of Transmissible Agents in Plasma-derived Preparations under Cautions.)


Vials of lyophilized α1-proteinase inhibitor and diluent should be at room temperature before reconstitution.1 3 11

Reconstitute vials of lyophilized α1-proteinase inhibitor with manufacturer-supplied sterile water for injection without preservatives.b c d Using the supplied transfer needle or device, add the appropriate volume of the supplied diluent to a vial containing α1-proteinase inhibitor. (See Table 1.)b c d Swirl vial gently to ensure dissolution; do not shake.b c d

Approximate amount (mg or g) of functionally active α1-proteinase inhibitor.b c d

Manufacturer-supplied sterile water for injection without preservatives.b c d

Table 1. Reconstitution of α1-Proteinase Inhibitor Preparations

α1-Proteinase Inhibitor Preparation

Dosage Strength Labeled on Vial

Diluent Volume


500 mg

25 mL1 16


1 g

50 mL1 16


500 mg

20 mL3 9 15


1 g

40 mL3 9 15


1 g

20 mL11 15

Resultant solution of Aralast, Prolastin, or Zemaira contains not less than (NLT) 16 mg, NLT 20 mg, or approximately 50 mg of α1-proteinase inhibitor per mL, respectively.1 3 15

For administration of large doses, several reconstituted vials may be pooled into an empty, sterile IV infusion container (e.g., empty IV bag or glass bottle) using aseptic technique.1 3 11 15

Withdraw reconstituted solutions of Aralast and Prolastin from the vial using a filter needle provided by the manufacturer.1 3 9 16

Reconstituted solutions contain no preservatives; administer within 3 hours after reconstitution.1 3 11

Any unused solution should be discarded; discard administration equipment in accordance with biohazard waste procedures.3 11 16 1 3 11

Rate of Administration

Administer Aralast at an infusion rate ≤0.08 mL/kg per minute.1 11

Administer Zemaira at an infusion rate of approximately 0.08 mL/kg per minute.b

Administer Prolastin at an infusion rate of ≥0.08 mL/kg per minute.b

If adverse effects occur, reduce infusion rate or temporarily interrupt infusion until manifestations subside.1 15 Infusion may then be resumed at a rate tolerated by the patient.1 15


Dosage of α1-proteinase inhibitor in mg is expressed in terms of functionally active α1-proteinase inhibitor, as determined by human neutrophil (Zemaira) or porcine pancreatic (Aralast, Prolastin) elastase inhibitory activity.1 3 5 10 11 15 16

Number of mg of functionally active α1-proteinase inhibitor is indicated on the label of each vial.1 3 11 15 16

Specific activity of functional α1-proteinase inhibitor in Aralast, Prolastin, or Zemaira is NLT 0.55, NLT 0.35, or NLT 0.7 mg, respectively, per mg of protein.1 3 11


Congenital α1-Proteinase Inhibitor Deficiency

60 mg/kg by IV infusion once weekly.1 3 11

Cautions for a1-Proteinase Inhibitor


  • Individuals with selective IgA deficiencies1 3 11 (IgA concentrations <15 mg/dL) who have antibodies to IgA.1

  • History of anaphylaxis or severe systemic reaction to α1-proteinase inhibitors.b

  • Known hypersensitivity to α1-proteinase inhibitor or any ingredient in the formulation.b



Risk of Transmissible Agents in Plasma-derived Preparations

Potential vehicle for transmission of human viruses (i.e., hepatitis A [HAV] or C virus [HCV]; HIV-1 or HIV-2; parvovirus B19)1 3 5 11 or other infectious agents.1 3 5 11

Despite stringent procedures (e.g., screening of plasma donors, application of a number of viral elimination/reduction steps) to prevent transmission of infectious agents, a risk of transmission still remains.1 3 11 12

Risk of viral infection should be weighed against the benefits of α1-proteinase inhibitor therapy.1 3 11

All infections thought possible to have been transmitted by α1-proteinase inhibitor products should be reported to the appropriate manufacturer.1 3 11

Risk of Creutzfeldt-Jakob Disease

May carry a risk of transmitting the causative agent of Creutzfeldt-Jakob disease (CJD), although transmission via human blood, blood components, or plasma derivatives (including α1-proteinase inhibitor) has not been documented.b c d e CJD is a rare, but invariably fatal, degenerative disease of the CNS associated with a poorly understood transmissable agent.e

There remains a theoretical risk that CJD can be transmitted through blood or blood products, although the risk is considered extremely remote.b c d e

Sensitivity Reactions

Hypersensitivity Reactions

Potential serious hypersensitivity reactions (e.g., anaphylactic or anaphylactoid reactions).1 11

If acute hypersensitivity reactions (e.g., hives, generalized urticaria, tightness of the chest, dyspnea, wheezing, faintness, hypotension, anaphylaxis) occur, discontinue immediately and institute appropriate therapy as indicated (e.g., epinephrine, corticosteroids, maintenance of an adequate airway, oxygen).1 11

General Precautions

Expansion of Plasma Volume

Transient expansion of plasma volume may occur during infusion; administer cautiously to patients at risk for circulatory overload.3 11

Specific Populations


Category C.b c d


Not known whether α1-proteinase inhibitor is distributed into milk.1 3 11 Caution advised if α1-proteinase inhibitor is used.1 3 11

Pediatric Use

Safety and efficacy not established.1

Hepatic Impairment

Use not recommended in patients with liver disease associated with α1-proteinase inhibitor deficiency.17

Common Adverse Effects

Headache,1 11 somnolence,1 delayed fever,3 lightheadedness,3 dizziness,3 11 asthenia,11 injection site pain,11 paresthesia,11 pruritus.11




Powder for Injection

Prolastin and Zemaira: ≤25°C; do not freeze.b d

Aralast: 2–8°C (may be exposed to ≤25°C); do not freeze.c Use within 1 month of removing from refrigeration.c


  • Inhibits serine proteases, which thereby helps prevent proteolytic destruction of the connective tissue framework of the lung parenchyma.1 3 11

Advice to Patients

  • Importance of patients understanding potential risks of therapy, including hypersensitivity reactions and possible transmission of infectious agents.1 3 11

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1 3 11

  • Importance of informing patients of other important precautionary information. (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Aralast and Zemaira must be obtained from specialty distributors; these preparations are not available through community pharmacies.4 15 For information regarding the Aralast distribution program, contact the manufacturer at 800-423-2090.4 For information regarding the distribution of Zemaira, contact the manufacturer at 866-ZEMAIRA (866-936-2472).15

α1-Proteinase Inhibitor (Human)


Dosage Forms


Brand Names



For injection, for IV infusion only

number of mg indicated on label

Aralast (with sterile water for injection diluent, a double-ended transfer needle, and filter)


number of mg indicated on label

Prolastin (with sterile water for injection diluent, double-ended transfer needle, filter needle)


number of mg indicated on label

Zemaira (with sterile water for injection diluent, a double-ended transfer needle, and filter)

ZLB Behring

AHFS DI Essentials™. © Copyright 2021, Selected Revisions April 1, 2009. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.


1. Baxter Healthcare Corporation. Aralast (alpha1-proteinase inhibitor[human]) prescribing information. Westlake Village, CA; 2003 Jan.

2. Coakley RJ, Taggart C, O’Neill S et al. α1-antitrypsin deficiency: biological answers to clinical questions. Am J Med Sci. 2001; 321:33-41.

3. Bayer Healthcare Corporation. Prolastin (alpha1-proteinase inhibitor [human]) prescribing information. Elkhart, IN; 2002 Jan.

4. Baxter Healthcare Corporation. Baxter announces launch of Aralast for patients with hereditary emphysema in need of new therapy. Deerfield,IL; 2003 May 30. Press release.

5. Stoller JK, Rouhani F, Brantly M et al. Biochemical efficacy and safety of a new pooled human plasma alpha(1)-antitrypsin, respitin. Chest. 2002; 122:66-74.

6. Stoller JK, Fallat R, Schluchter MD et al. Augmentation therapy with alpha1-antitrypsin: patterns of use and adverse events. Chest. 2003; 123:1425-34.

7. The Alpha-1-Antitrypsin Deficiency Registry Study Group. Survival and FEV1 decline in patients with severe deficiency of α1-antitrypsin. Am J Respir Care Med. 1998; 158:49-59.

8. Wencker M, Fuhrmann B, Banik N et al. Longitudinal follow-up of patients with alpha(1)-protease inhibitor deficiency before and during therapy with IV alpha(1) protease inhibitor. Chest. 2001; 119:676-8.

9. Bayer Pharmaceutical Division, West Haven, CT: Personal communication.

10. Coan MH, Brockway WJ, Eguizabal H et al. Preparation and properties of alpha1-proteinase inhibitor concentrate from human plasma. Vox Sang. 1985; 48:333-42.

11. Aventis Behring. Alpha1-proteinase inhibitor (Zemaira) prescribing information. Kankakee, IL; 2003 Jul.

12. AuBuchon JP, Birkmeyer JD. Safety and cost-effectiveness of solvent-detergent-treated plasma. In search of a zero-risk blood supply. JAMA. 1994; 272:1210-4.

13. Seersholm N, Wencker M, Banik N et al. Does α1-antitrypsin augmentation therapy slow the annual decline in FEV1 in patients with severe hereditary α1-antitrypsin deficiency? Eur Respir J. 1997; 10:2260-3.

14. Dirksen A, Dijkman JH, Madsen F et al. A randomized clinical trial of α1-antitrypsin augmentation therapy. Am J Respir Care Med. 1999; 160:1468-72.

15. ZLB Behring, King of Prussia, PA: Personal communication.

16. Baxter Healthcare, Westlake Village, CA: Personal communication.

17. Anon. American Thoracic Society/European Respiratory Society Statement: Standards for the diagnosis and management of individuals with alpha-1 antitrypsin deficiency. Am J Respir Crit Care Med. 2003; 168:818-900.

a. AHFS drug information 2006. McEvoy GK, ed. α1-Proteinase Inhibitor (Human). Bethesda, MD: American Society of Health-System Pharmacists; 2006:2678-80.

b. ZLB Behring LLC. Alpha1-proteinase inhibitor Zemaira (alpha1-proteinase inhibitor[human]) prescribing information. Kankakee, IL; 2006 Mar.

c. Baxter Healthcare Corporation. Aralast (alpha1-proteinase inhibitor[human]) prescribing information. Westlake Village, CA; 2005 Aug.

d. Talecris Biotherapeutics, Inc. Prolastin (alpha1-proteinase inhibitor [human]) prescribing information. Research Triangle Park, NC; 2005 Jan.

e. AHFS drug information 2006. McEvoy GK, ed. Albumin Human. Bethesda, MD: American Society of Health-System Pharmacists; 2006:1414-6.