Dosing and uses of Plegridy (peginterferon beta-1a)
Adult dosage forms and strengths
injection solution, prefilled syringe
- 63mcg/0.5mL and 94mcg/0.5mL starter pack
- 125mcg/0.5mL
injection solution, prefilled pen for autoinjector
- 63mcg/0.5mL and 94mcg/0.5mL starter pack
- 125mcg/0.5mL
Multiple Sclerosis
Indicated for relapsing forms of multiple sclerosis
Administer SC q2wk with the following initial titration schedule:
Day 1: 63 mcg SC once
Day 15: 94 mcg SC once
Beginning on day 29 and thereafter: 125 mcg SC q2wk
Administration
Prophylactic use of analgesics and/or antipyretics may prevent/ameliorate flulike symptoms associated with treatment
Remove from refrigerator and allow to warm to room temperature (~30 min) before injection (do not use external heat sources, such as warm water)
Train patients in the proper technique for self-administering SC injections
Patient should check the injection site for redness, swelling, and tenderness 2 hr after administering
Rotate sites for SC injections between the abdomen, back of the upper arm, and thigh
Storage
- Store in the closed original carton to protect from light until ready for injection
- Refrigerate between 2-8°C (36-46°F)
- Do not freeze; discard if frozen
- If refrigeration unavailable, may be stored between 2-25°C (36-77°F) for up to 30 days, protected from light
- Can be removed from, and returned to, a refrigerator if necessary
- Do not exceed a total combined time out of refrigeration of 30 days within a temperature range of 2-25°C (36-77°F)
Pediatric dosage forms and strengths
Safety and efficacy not established
Geriatric dosage forms and strengths
Safety and efficacy not established
Plegridy (peginterferon beta-1a) adverse (side) effects
>10%
Injection site reactions (66%)
Injection site erythema (62%)
Influenzalike illness (47%)
Pyrexia (45%)
Headache (44%)
Myalgia (19%)
Chills (17%)
Asthenia (13%)
Injection site pruritus (13%)
Arthralgia (11%)
1-10%
Nausea (9%)
Depression (8%); not different from placebo
CHF, cardiomyopathy (7%); not different from placebo
Decreased WBCs (7%)
Increased ALT (6%)
Vomiting (5%)
Pain (5%)
Hyperthermia (4%)
Pruritus (4%)
Increased AST (4%)
Increased GGT (3%)
Injection site edema (3%)
Injection site warmth (3%)
Injection site hematoma (3%)
Injection site rash (2%)
Increased ALT, >5 x ULN (2%)
<1
Increased AST, >5 x ULn
Seizures
Anaphylaxis, angioedema, urticaria
Autoimmune disorders
Warnings
Contraindications
History of hypersensitivity to natural or recombinant interferon beta or peginterferon
Cautions
Severe hepatic injury, including hepatitis, autoimmune hepatitis, and rare cases of severe hepatic failure, reported; monitor liver function tests and consider discontinuing if hepatic injury occurs
Depression, suicidal ideation, and suicide occur more frequently in patients receiving interferon beta than in patients receiving placebo; advise patients to report immediately any symptom of depression and consider discontinuing if depression occurs
Seizures are associated with the use of interferon beta (<1%)
Anaphylaxis and other allergic reactions reported (rare); discontinue if a serious allergic reaction occurs
Injection site reactions reported, including site necrosis; change injection site; if multiple injection lesions occur, discontinue until healing occurs
Congestive heart failure and/or cardiomyopathy reported (7% in both peginterferon beta-1a- and placebo-treated patients)
Decreased peripheral blood counts reported in all cell lines, including rare instances of pancytopenia and severe thrombocytopenia; monitor for symptoms of infections, bleeding, and anemia; monitor CBC counts, differential WBC counts, and platelet counts
Autoimmune disorders of multiple target organs, including idiopathic thrombocytopenia, hyper- and hypothyroidism, and autoimmune hepatitis, have been reported
In patients with renal impairment, monitor for adverse reactions because of increased systemic exposure
Cases of thrombotic microangiopathy, including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, some fatal, reported; some cases have been reported several weeks to years after starting interferon beta products; discontinue therapy if clinical symptoms and laboratory findings consistent with TMA occur, and manage as clinically indicated
Pregnancy and lactation
Pregnancy category: C
Encourage patients to enroll in pregnancy exposure registry that monitors pregnancy outcomes in women exposed to drug during pregnancy (1-866-810-1462 or visiting https://www.plegridypregnancyregistry.com/)
Lactation: Unknown if distributed in human breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Plegridy (peginterferon beta-1a)
Mechanism of action
The exact mechanism by which peginterferon beta-1a exerts its effects in patients with multiple sclerosis is unknown; interferons are thought to alter response to surface antigen and may enhance immune cell activities
Absorption
Does not accumulate in serum after multiple doses
Peak plasma concentration: 280 pg/mL
Peak plasma time: 1-1.5 days
AUC over 14 day interval: 34.8 ng•hr/mL
Distribution
481 L
Metabolism
Not extensively metabolized in the liver
Elimination
Half-life: 78 hr
Steady state clearance: 4.1 L/hr
Excretion: Mostly in urine
