Interferon beta-1a Interferon beta-1b
(r1FN-B)
Interferon beta-1a (Avonex)
Interferon Beta-1a/-1b
Interferon beta-1b (Betaseron)
r1FN-B (Betaseron)
Interferon Beta-1a/-1b
(in-ter- FEER-on BAY-tah)
Pregnancy Category: C Avonex (Interferon beta-1a) Betaseron (Interferon beta-1b) (Rx)

Classification: Drug for multiple sclerosis (MS)

Action/Kinetics: Interferon beta-1a is produced by mammalian cells into which the human interferon beta gene has been introduced. Interferon beta-1b is made by bacterial fermentation of a strain of Escherichia coli that is a genetically engineered plasmid containing the gene for human interferon beta _ser17. Interferon betas have antiviral, antiproliferative, and immunoregulatory effects. Mechanism for the beneficial effect in MS is unknown, although the effects are mediated through combination with specific cell receptors located on the cell membrane. The receptor-drug complex induces the expression of a number of interferon-induced gene products that are thought to be the mediators of the biologic effects of interferon beta-1a and beta-1b. t 1/2, interferon beta-1a: 10 hr. Kinetic information is not available for interferon beta-1b since serum levels are low or not detectable following SC administration to MS clients. Peak serum levels of beta-1b: Within 1-8 hr with a mean serum concentration of 40 IU/mL. Mean terminal half-lives ranged from 8 min to 4.3 hr.

Uses: Interferon beta-1a: Treatment of relapsing forms of MS to slow the appearance of physical disability and decrease the frequency of clinical exacerbations. Interferon beta-1b: Treatment of ambulatory clients with relapsing-remitting MS to reduce the frequency of clinical exacerbations. Remitting-relapsing MS is manifested by recurrent attacks of neurologic dysfunction followed by complete or incomplete recovery. Investigational: Treatment of AIDS, AIDS-related Kaposi's sarcoma, metastatic renal cell carcinoma, herpes of the lips or genitals, malignant melanoma, cutaneous T-cell lymphoma, and acute non-A/non-B hepatitis.

Contraindications: Hypersensitivity to natural or recombinant interferon beta or human albumin. Lactation.

Special Concerns: The safety and efficacy for use in chronic progressive MS and in children less than 18 years of age have not been studied. Depression and attempted suicide and suicide have occurred. Potential to be an abortifacient. Use with caution in those with preexisting seizure disorder.

Side Effects: Side effects common to interferon beta-1a and beta-1b. Body as a whole: Headache, fever, flu-like symptoms, pain, asthenia, chills, reaction at injection site (including necrosis/inflammation), malaise. GI: Abdominal pain, diarrhea, dry mouth, GI hemorrhage gingivitis, hepatomegaly, intestinal obstruction, periodontal abscess, proctitis. CV: Arrhythmia, hypotension, postural hypotension. CNS: Dizziness, speech disorder, convulsion, suicide attempt, abnormal gait, depersonalization, facial paralysis, hyperesthesia, neurosis, psychosis. Respiratory: Sinusitis, dyspnea, hemoptysis, hyperventilation. Musculoskeletal: Myalgia, arthritis. Dermatologic: Contact dermatitis, furunculosis, seborrhea, skin ulcer. GU: Epididymitis, gynecomastia, hematuria, kidney calculus, nocturia, vaginal hemorrhage, ovarian cyst. Miscellaneous: Abscess, ascites, cellulitis, hernia, hypothyroidism, sepsis hiccoughs, thirst, leukorrhea.
Interferon beta-1a. Body as a whole: Infection. GI: Nausea, dyspepsia, anorexia, blood in stool, colitis, constipation, diverticulitis, gall bladder disorder, gastritis, gum hemorrhage, hepatoma, increased appetite, intestinal perforation periodontitis, tongue disorder. CV: Syncope, vasodilation, arteritis, heart arrest, hemorrhage, pulmonary embolus palpitation, pericarditis, peripheral ischemia, peripheral vascular disorder, spider angioma, telangiectasia. CNS: Sleep difficulty, muscle spasm, ataxia, amnesia, Bell's palsy, clumsiness, drug dependence, increased libido. Respiratory: URTI, emphysema, laryngitis, pharyngeal edema, pneumonia. Musculoskeletal: Arthralgia, bone pain, myasthenia, osteonecrosis, synovitis. Dermatologic: Urticaria, alopecia, nevus, herpes zoster, herpes simplex, basal cell carcinoma, blisters, cold clammy skin, erythema, genital pruritus, skin discoloration. GU: Vaginitis, breast fibroadenosis, breast mass, dysuria, fibrocystic change of the breast, fibroids, kidney pain, menopause, pelvic inflammatory disease, penis disorder, Peyronie's disease, polyuria, postmenopausal hemorrhage, prostatic disorder, pyelonephritis, testis disorder, urethral pain, urinary urgency, urinary retention, urinary incontinence. Hematologic: Anemia, ecchymosis at injection site, eosinophils greater than 10%, hematocrit less than 37%, increased coagulation time, ecchymosis, lymphadenopathy, petechia. Metabolic: Dehydration, hypoglycemia, hypomagnesemia, hypokalemia. Ophthalmic: Abnormal vision, conjunctivitis, eye pain, vitreous floaters. Miscellaneous: Otitis media, decreased hearing, facial edema, fibrosis at injection site, hypersensitivity at injection site, lipoma, neoplasm, photosensitivity, toothache, sinus headache, chest pain.
Interferon beta-1b. Body as a whole: Generalized edema, hypothermia, anaphylaxis, shock adenoma, sarcoma. GI: Constipation, vomiting, GI disorder, aphthous stomatitis, cardiospasm, cheilitis, cholecystitis, cholelithiasis, duodenal ulcer, enteritis, esophagitis, fecal impaction or incontinence, flatulence, gastritis, glossitis, hematemesis, hepatic neoplasia, hepatitis, ileus, increased salivation, melena, nausea, oral leukoplakia, oral moniliasis, pancreatitis, rectal hemorrhage salivary gland enlargement, stomach ulcer, peritonitis, tenesmus. CV: Migraine, palpitation, hypertension, tachycardia, peripheral vascular disorder, hemorrhage angina pectoris, atrial fibrillation, cardiomegaly, cardiac arrest, cerebral hemorrhage, heart failure, MI, pulmonary embolus, ventricular fibrillation cerebral ischemia, endocarditis, pericardial effusion, spider angioma, subarachnoid hemorrhage, syncope, thrombophlebitis, thrombosis, varicose veins, vasospasm, venous pressure increase, ventricular extrasystoles. CNS: Mental symptoms, hypertonia, somnolence, hyperkinesia, acute/chronic brain syndrome, agitation, apathy, aphasia, ataxia, brain edema, coma delirium, delusions, dementia, dystonia, encephalopathy, euphoria, hallucinations, hemiplegia, hypalgesia, incoordination, intracranial hypertension, decreased libido, manic reaction, meningitis, neuralgia, neuropathy, paralysis, paranoid reaction, decreased reflexes, stupor, subdural hematoma, torticollis, tremor. Respiratory: Laryngitis, apnea, asthma, atelectasis, lung carcinoma, hypoventilation, interstitial pneumonia, lung edema, pleural effusion, pneumothorax. Musculoskeletal: Myasthenia, arthrosis, bursitis, leg cramps, muscle atrophy, myopathy, myositis, ptosis, tenosynovitis. Dermatologic: Sweating, alopecia, erythema nodosum, exfoliative dermatitis, hirsutism, leukoderma, lichenoid dermatitis, maculopapular rash, photosensitivity, psoriasis, benign skin neoplasm, skin carcinoma, skin hypertrophy, skin necrosis, urticaria, vesiculobullous rash. GU: Dysmenorrhea, menstrual disorder, metrorrhagia, cystitis, breast pain, menorrhagia, urinary urgency, fibrocystic breast, breast neoplasm, urinary retention, anuria, balanitis, breast engorgement, cervicitis, impotence, kidney failure, tubular disorder, nephritis, oliguria, polyuria, salpingitis, urethritis, urinary incontinence, enlarged uterine fibroids, uterine neoplasm. Hematologic: Lymphocytes less than 1500/mm ³, active neutrophil count less than 1500/mm ³, WBCs less than 3000/mm ³, lymphadenopathy, chronic lymphocytic leukemia, petechia, hemoglobin less than 9.4 g/dL, platelets less than 75,000/mm ³, splenomegaly. Metabolic: Weight gain, weight loss, goiter, glucose less than 55 mg/dL or greater than 160 mg/dL, AST or ALT greater than 5 times baseline, total bilirubin greater than 2.5 times baseline, urine protein greater than 1+, alkaline phosphatase greater than 5 times baseline, BUN greater than 40 mg/dL, calcium greater than 11.5 mg/dL, cyanosis, edema, glycosuria, hypoglycemic reaction, hypoxia, ketosis. Ophthalmic: Conjunctivitis, abnormal vision, diplopia, nystagmus, oculogyric crisis, papilledema, blepharitis, blindness, dry eyes, iritis, keratoconjunctivitis, mydriasis, photophobia, retinitis, visual field defect. Miscellaneous: Pelvic pain, hydrocephalus, alcohol intolerance, otitis externa, otitis media, parosmia, taste loss, taste perversion.

Laboratory Test Alterations: ALT, total bilirubin, AST, BUN, urine protein. Hypoglycemia or hyperglycemia. Ketosis.

How Supplied: Kit: 33 mcg; Powder for injection: 0.3 mg

Dosage
?Interferon beta-1a: IM Relapsing forms of MS.
30 mcg IM once a week.
?Inteferon beta-1b: SC Relapsing-remitting MS clients.
0.25 mg (8 mIU) every other day.