abatacept
Pharmacologic class: Selective costimulation modulator
Therapeutic class: Antirheumatic
Pregnancy risk category C
Action
Inhibits T-cell activation by binding to CD80 and CD86, blocking interaction with CD28. (This interaction triggers costimulatory signal necessary for full activation of T cells, which are implicated in rheumatoid arthritis pathogenesis.)
Availability
Injection: 125 mg/ml in prefilled syringes
Powder for infusion (lyophilized): 250 mg/15 ml in single-use vial
Indications and dosages
➣ Moderate to severe adult rheumatoid arthritis as monotherapy or concomitantly with disease-modifying antirheumatic drugs other than tumor necrosis factor (TNF) antagonists
Adults weighing less than 60 kg (132 lb): 500 mg I.V. given over 30 minutes at weeks 0, 2, and 4; thereafter, give every 4 weeks. Or, 500 mg I.V. as a loading dose followed by 125 mg subcutaneously within a day, followed by 125 mg subcutaneously once weekly. For patients unable to receive an infusion, initiate weekly injections subcutaneously without an I.V. loading dose.
Adults weighing 60 to 100 kg (132 to 220 lb): 750 mg I.V. given over 30 minutes at weeks 0, 2, and 4; thereafter, give every 4 weeks. Or 750 mg I.V. as a loading dose followed by 125 mg subcutaneously within a day, followed by 125 mg subcutaneously once weekly. For patients unable to receive an infusion, may initiate weekly injections subcutaneously without an I.V. loading dose.
Adults weighing more than 100 kg:
1 g I.V. given over 30 minutes at weeks 0, 2, and 4; thereafter, give every 4 weeks. Or 1 g I.V. as a loading dose followed by 125 mg subcutaneously within a day, followed by 125 mg subcutaneously once weekly. For patients unable to receive an infusion, may initiate weekly injections subcutaneously without an I.V. loading dose.
➣ Moderately to severely active polyarticular juvenile idiopathic arthritis as monotherapy or concomitantly with methotrexate
Children age 6 and older weighing less than 75 kg: 10 mg/kg I.V. at weeks 0, 2, and 4; thereafter give every 4 weeks. Not to exceed a maximum dosage of 1 g.
Contraindications
• Hypersensitivity to drug or its components
Precautions
Use cautiously in:
• increased risk of infection or history of recurrent infections, immunocompromised state, chronic obstructive pulmonary disease (COPD)
• concurrent use of concomitant TNF antagonists
• patients older than age 65
• pregnant or breastfeeding patients
• children (safety and efficacy not established).
Administration
☞ Reconstitute each vial with 10 ml sterile water for injection, using only silicone-free disposable syringe included with product.
☞ During reconstitution, rotate vial by swirling gently. Avoid prolonged or vigorous agitation. Don't shake.
• Further dilute reconstituted solution to volume of 100 ml with normal saline solution.
• Use silicone-free syringe to add drug to infusion bag or bottle, and mix gently. Resulting drug concentration should be 5 mg/ml for two vials, 7.5 mg/ml for three vials, or 10 mg/ml for four vials, respectively.
• Administer infusion over 30 minutes using infusion set and nonpyrogenic, low protein-binding filter.
• Complete infusion within 24 hours of vial reconstitution.
• Don't infuse other drugs concurrently through same I.V. line.
• Watch for infusion-related reactions (hypotension or hypertension, dyspnea, nausea, dizziness, headache, flushing, urticaria, pruritus, rash, cough, or wheezing), which usually occur within 1 hour of administration. Be prepared to intervene appropriately.
Adverse reactions
CNS: headache, dizziness
CV: hypertension, hypotension
EENT: nasopharyngitis
GI: nausea, dyspepsia, diverticulitis
GU: urinary tract infection, acute pyelonephritis
Musculoskeletal: back pain, extremity pain
Respiratory: cough, upper respiratory tract infection, pneumonia, wheezing, bronchitis, dyspnea
Skin: rash, flushing, urticaria, pruritus
Other: herpes zoster, pain, injection-site reactions, malignancies, infusion-related reactions, hypersensitivity reaction
Interactions
Drug-drug. Immunizations: possible decrease in immunization efficacy
Patient monitoring
• Continue to monitor patient for infusion-related events.
• Assess patient's overall health at each visit to evaluate infection status.
• Closely monitor COPD patient because of increased likelihood of adverse events.
Patient teaching
• If patient will self-administer drug, tell him to follow exact directions for injection and proper disposal of needles and syringes.
• Instruct patient to report signs and symptoms of infection.
• Caution patient to avoid immunizations during or within 3 months of stopping drug.
• Tell female with childbearing potential that pregnancy and breastfeeding aren't recommended during therapy.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs mentioned above.