Drug Guide
Peginterferon Beta-1a
Classification
Therapeutic: Multiple sclerosis (MS) treatment
Pharmacological: Interferon beta
FDA Approved Indications
- Relapsing multiple sclerosis
Mechanism of Action
Modulates the immune response by reducing inflammatory activity and cytokine production, thereby decreasing the frequency of MS relapses and slowing disease progression.
Dosage and Administration
Adult: 125 mcg subcutaneously every 14 days, with dose escalation as tolerated; some patients may require adjustments based on response and tolerability.
Pediatric: Not approved for pediatric use.
Geriatric: No specific dosage adjustments; use with caution due to potential comorbidities.
Renal Impairment: No specific adjustment required.
Hepatic Impairment: No specific adjustment required.
Pharmacokinetics
Absorption: Well absorbed after subcutaneous administration.
Distribution: Limited distribution, primarily to extracellular fluid.
Metabolism: Degraded by proteolytic enzymes into amino acids; no significant hepatic metabolism.
Excretion: Excreted as amino acids after breakdown.
Half Life: Approximately 4.7 days.
Contraindications
- Hypersensitivity to peginterferon beta-1a or other interferons.
- Active severe infections.
Precautions
- Monitor for liver function abnormalities.
- Use with caution in patients with depression or history of psychiatric disorders.
- Risk of autoimmune disorders; monitor accordingly.
Adverse Reactions - Common
- Flu-like symptoms (fever, chills, fatigue) (Frequent)
- Injection site reactions (Common)
- Headache (Common)
- Myalgia (Common)
Adverse Reactions - Serious
- Hepatotoxicity (liver enzyme elevation, hepatitis) (Uncommon)
- Depression or suicidal ideation (Uncommon)
- Neuropsychiatric disorders (Uncommon)
- Blood cell count abnormalities (neutropenia, anemia) (Uncommon)
Drug-Drug Interactions
- Increase risk of adverse effects when used with other immunomodulators, immunosuppressants, or hepatotoxic drugs.
Drug-Food Interactions
- No specific interactions documented.
Drug-Herb Interactions
- Limited data; caution advised with herbal supplements that affect immune function.
Nursing Implications
Assessment: Monitor liver function tests, complete blood counts, and mental health status regularly.
Diagnoses:
- Risk for infection, fatigue, or depression.
Implementation: Administer as scheduled, educate on injection technique, and monitor for adverse reactions.
Evaluation: Assess efficacy via reduction in relapse rate and MRI findings; monitor tolerability.
Patient/Family Teaching
- Report any signs of depression or suicidal thoughts.
- Educate on proper injection technique and site rotation.
- Inform about common side effects and when to seek medical attention.
- Emphasize adherence to dosing schedule.
Special Considerations
Black Box Warnings:
- Neuropsychiatric disorders, including depression and suicidal ideation.
- Hepatotoxicity.
- Aggressive and fatal infections.
Genetic Factors: No specific genetic considerations.
Lab Test Interference: May cause false-positive results in certain immune or infectious disease tests.
Overdose Management
Signs/Symptoms: Severe flu-like symptoms, hypersensitivity reactions, or signs of neuropsychiatric disturbance.
Treatment: Supportive care; manage symptoms accordingly; no specific antidote.
Storage and Handling
Storage: Store refrigerated at 2°C to 8°C (36°F to 46°F). Protect from light.
Stability: Stable under recommended storage conditions until expiration date.