Names and pronunciation
Betaseron, Extavia
PDF page 709
Loading InternPractice…
Drug reference
Betaseron, Extavia
PDF page 709
Func. class.: Antiviral
PDF page 709
Chem. class.: Interferon, Escherichia coli derivative
PDF page 709
ACTION: Antiviral, immunoregula- tory; action not clearly understood; bio- logic response-modifying properties mediated through specific receptors on cells, inducing expression of interferon- induced gene products
PDF page 709
USES: Ambulatory patients with relapsing or remitting MS
PDF page 709
CONTRAINDICATIONS: Hyper- sensitivity to natural or recombinant interferon-β or human albumin, hamster protein, rotavirus vaccine Precautions: Pregnancy, breastfeeding, children <18 yr, chronic progressive MS, depression, mental disorders, seizure disorder, latex allergy, autoimmune dis- orders, bone marrow suppression, hepa- totoxicity, cardiac disease, alcoholism, chickenpox, herpes zoster
PDF pages 709, 710
SIDE EFFECTS CNS: Headache, fever, pain, chills, mental changes, depression, hyperto- nia, suicide attempts, seizures CV: Migraine, palpitations, hypertension, tachycardia, peripheral vascular disorders EENT: Conjunctivitis, blurred vision GI: Diarrhea, constipation, vomiting, abdominal pain GU: Dysmenorrhea, irregular menses, metrorrhagia, cystitis, breast pain HEMA: Decreased lymphocytes, ANC, WBC, lymphadenopathy, anemia INTEG: Sweating, inj-site reaction MS: Myalgia, myasthenia RESP: Sinusitis, dyspnea
PDF pages 711, 712
INTERACTIONS Increase: hepatic damage—antiretrovi- rals (NNRTIs, NRTIs, protease inhibitors) Increase: myelosuppression—antineo- plastics Decrease: clearance of zidovudine Drug/Herb • Change in immunomodulation: astrag- alus, echinacea, melatonin Drug/Lab Test Interference: vaccines, toxoids; avoid concurrent use Increase: LFTs
PDF page 712
DOSAGE AND ROUTES Interferon beta-1a Multiple sclerosis • Adult: IM (Avonex) 30 mcg/wk • Adult: SUBCUT (Rebif) 22 or 44 mcg 3×/wk with each dose 48 hr apart, titrate to full dose over 4-wk period Interferon beta-1b Multiple sclerosis • Adult: SUBCUT 0.0625 mg every other day for wk 1 and 2, then 0.125 mg every other day for wk 3 and 4, then 0.1875 mg every other day for wk 5 and 6, then 0.25 mg every other day thereafter; higher doses should not be used
PDF page 710
Available forms: beta-1a: (Avonex) 30 mcg (6.6 million international units/vial) (autoinjector pen); (Rebif) 22 mcg, 44 mcg/0.5 mL; beta-1b: powder for inj 0.3 mg kit Administer Interferon beta-1a • Visually inspect parenteral products for particulate matter and discoloration before use • Store in refrigerator; do not freeze IM route • Premedicate with acetaminophen or ibuprofen and give at bedtime to lessen flulike symptoms • Interferon-β1a (Avonex) 30 mcg = 6 million IU • If a dose is missed, give it as soon as possible; continue regular schedule but do not give 2 injections within 2 days; all products are single-use only; do not re- use needles, syringes, prefilled syringes, or autoinjectors • Rotate injection sites to minimize in- jection-site reactions • Do not inject into an area where skin is irritated, reddened, bruised, infected, or scarred • Check site after 2 hr for redness, edema, or tenderness • The manufacturer of Avonex offers free training on IM use for patients and health care partners; contact Above MS for more information (800-456-2255) Reconstitution and administration of Avonex lyophilized powder for IM route • Use aseptic technique for preparation of solution • Sites include the thigh or upper arm • Slowly add 1.1 mL sterile water for injection, preservative-free (supplied by manufacturer) to the vial; rapid ad- dition of the diluent can cause foaming • Gently swirl; do not shake; final con- centration should be 30 mcg/mL (6 mil- lion IU/mL) • The solution should be clear to slightly yellow without particles; discard if the reconstituted product contains particu- late or is discolored • Withdraw 1 mL of reconstituted solu- tion into a syringe; attach the sterile needle and inject IM • A 25-G 1-inch needle for IM may be substituted for the 23-G 11 4-inch needle provided • Storage: Use within 6 hr of reconstitu- tion; store reconstituted solution in re- frigerator; do not freeze; discard any unused solution; both drug and diluent vials are single-use only Administration of Avonex prefilled syringe • The first injection should be per- formed under the supervision of an ap- propriately qualified person • If self-injecting, rotate injection site between thighs • Wash hands before handling the Dose Pack • Remove prefilled syringe from the re- frigerator to warm to room temperature (usually 30 min before use); do not use external heat sources such as hot water to warm the syringe • Refer to the Patient Medication Guide for detailed instructions for preparing and giving a dose • Storage: Store refrigerated; if refrig- eration is unavailable, may store at 77°F or less for up to 7 days; after removing from refrigerator, do not store product above 25°C Administration of Avonex prefilled auto- injector • The first injection should be performed under the supervision of provider • Remove one Administration Dose Pack from the refrigerator to warm to room temperature (about 30 min before use); do not use external heat sources such as hot water to warm the syringe Dose Pack • Do not use the injection if the liquid is colored, cloudy, or has lumps or particles; air bubbles will not affect the dose • Avonex Pen should be injected into the upper outer thigh • Refer to the Patient Medication Guide for detailed instructions for preparing and giving a dose • Storage: Store at 36°F-46°F (2°C-8°C); if refrigeration is unavailable, may store at 77°F or less for up to 7 days; after remov- ing from refrigerator, do not store product above 25°C; do not expose to high tem- peratures; do not freeze; protect from light Subcutaneous administration • Give at the same time (preferably late in the afternoon or evening) on the same days of the week at least 48 hours apart • Do not give on two consecutive days; if a dose is missed, administer the dose as soon as possible, then skip the following day; return to the regular schedule the following week • Premedication with acetaminophen or ibuprofen can lessen the severity of flu- like symptoms • Interferon-β1a (Rebif) 44 mcg is equivalent to 12 million IU • Rotate injection sites • A Starter Pack containing a lower dose of Rebif syringes is available for the initial titration period Injection (Rebif) • Interferon-β1a (Rebif) is available in a prefilled syringe with a 29-G needle • Inject subcut into the outer surface of the upper arm, abdomen, thigh, or but- tock, do not inject the area near the navel or waistline; take care not to inject intra- dermally • Discard any unused solution; prefilled syringes do not contain preservatives and are single-use only Interferon beta-1b SUBCUT route • The manufacturers of Betaseron and of Extavia offer materials to assist with train- ing on subcut use, call 1-800-788-1467 (Betaseron), 1-888-669-6682 (Extavia) I • Premedication with acetaminophen or ibuprofen and use of product at bedtime can lessen the severity of flulike symptoms • Visually inspect parenteral products for particulate matter and discoloration before use; do not use if particulate mat- ter is present Reconstitution • Add 1.2 mL of 0.54% sodium chloride injection (supplied by the manufacturer) to the vial by using the vial adapter to attach the prefilled syringe that contains the diluent • If not used immediately, store in the refrigerator for up to 3 hr; do not freeze; discard any unused portion after 3 hr Injection • Withdraw the desired amount of the reconstituted solution into the syringe • Choose an injection site on the upper back arm, abdomen, buttock, or front thigh; do not inject within 2 inches of the navel or in a site where the skin is red, bruised, infected, broken, painful, un- even, or scabbed; rotate injection sites • Inject subcut; take care not to inject intradermally
PDF pages 710, 711
Assess: • Blood, hepatic studies: CBC, differen- tial, platelet counts, BUN, creatinine, ALT, urinalysis; if absolute neutrophil count <750/mm3 or if AST/ALT is 10× normal, discontinue product • CNS symptoms: headache, fatigue, de- pression • GI status: diarrhea or constipation, vomiting, abdominal pain • Cardiac status: increased B/P, tachycardia • Mental status: depression, deperson- alization, suicidal thoughts, insomnia • Lupus-like symptoms • Multiple sclerosis symptoms
PDF page 712
Evaluate: • Therapeutic response: decreased symptoms of multiple sclerosis
PDF page 712
CLINICAL CONSIDERATIONS
PDF page 712
Patient and caregiver information: • With written, detailed information about product • That blurred vision, hearing loss, sweating may occur • That female patients may experience irregular menses, dysmenorrhea or me- trorrhagia, breast pain • To use sunscreen to prevent photosen- sitivity • About injection technique, care of equipment • To notify prescriber of increased tem perature, chills, muscle soreness, fatigue, depression, symptoms of hepatotoxicity • To notify prescriber if pregnancy is suspected
PDF page 712
PHARMACOKINETICS β-1a: Onset ≤12 hr, peak 16 hr, duration 4 days, half-life 8.6 hr β-1b: Onset rapid, peak 2-8 hr, duration unknown, half-life 8 min-4.3 hr
PDF page 712
• Adult: IM (Avonex) 30 mcg/wk
PDF page 710
• Adult: SUBCUT (Rebif) 22 or 44 mcg 3×/wk with each dose 48 hr apart, titrate to full dose over 4-wk period Interferon beta-1b Multiple sclerosis
PDF page 710
• Adult: SUBCUT 0.0625 mg every other day for wk 1 and 2, then 0.125 mg every other day for wk 3 and 4, then 0.1875 mg every other day for wk 5 and 6, then 0.25 mg every other day thereafter; higher doses should not be used
PDF page 710