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Extavia Dosage

Generic name: INTERFERON BETA-1B 0.25mg in 1.0mL;
Dosage form: injection
Drug class: Interferons

Medically reviewed by Last updated on Apr 22, 2024.

2.1 Dosing Information

The recommended starting dose is 0.0625 mg (0.25 mL) subcutaneously every other day, with dose increases over a six-week period to the recommended dose of 0.25 mg (1 mL) every other day (see Table 1).

Table 1: Schedule for Dose Titration
aDosed every other day, subcutaneously.



Percentage of
recommended dose


Weeks 1-2

0.0625 mg


0.25 mL

Weeks 3-4

0.125 mg


0.5 mL

Weeks 5-6

0.1875 mg


0.75 mL

Week 7 and thereafter

0.25 mg


1 mL

If a dose of EXTAVIA is missed, then it should be taken as soon as the patient remembers or is able to take it. The patient should not take EXTAVIA on two consecutive days. The next injection should be taken about 48 hours (two days) after that dose. If the patient accidentally takes more than their prescribed dose, or takes it on two consecutive days, they should be instructed to call their healthcare provider immediately.

2.2 Reconstitution of the Lyophilized Powder

a) Prior to reconstitution, verify that the vial containing lyophilized EXTAVIA is not cracked or damaged. Do not use cracked or damaged vials.

b) To reconstitute lyophilized EXTAVIA for injection, attach the pre-filled syringe containing the diluent (0.54% sodium chloride solution, USP) to the EXTAVIA vial using the vial adapter.

The removable rubber cap of the diluent (0.54% sodium chloride solution, USP) pre-filled syringe contains natural rubber latex, which may cause allergic reactions and should not be handled by latex-sensitive individuals.

c) Slowly inject 1.2 mL of diluent into the EXTAVIA vial.

d) Gently swirl the vial to dissolve the lyophilized powder completely; do not shake. Foaming may occur during reconstitution or if the vial is swirled or shaken too vigorously. If foaming occurs, allow the vial to sit undisturbed until the foam settles.

e) 1 mL of reconstituted EXTAVIA solution contains 0.25 mg of interferon beta-1b.

f) After reconstitution, if not used immediately, refrigerate the reconstituted EXTAVIA solution at 35°F to 46°F (2°C to 8°C) and use within three hours. Do not freeze.

2.3 Important Administration Instructions

a) Perform the first EXTAVIA injection under the supervision of an appropriately qualified healthcare professional. If patients or caregivers are to administer EXTAVIA, train them in the proper subcutaneous injection technique and assess their ability to inject subcutaneously to ensure the proper administration of EXTAVIA.

b) Visually inspect the reconstituted EXTAVIA solution before use; discard if it contains particulate matter or is discolored.

c) Keeping the syringe and vial adapter in place, turn the assembly over so that the vial is on top. Withdraw the appropriate dose of EXTAVIA solution. Remove the vial from the vial adapter before injecting EXTAVIA.

d) Use safe disposal procedures for needles and syringes.

e) Do not re-use needles or syringes.

f) Advise patients and caregivers to rotate sites for subcutaneous injections to minimize the likelihood of severe injection site reactions, including necrosis or localized infection [see Warnings and Precautions (5.5)].

2.4 Premedication for Flu-like Symptoms

Concurrent use of analgesics and/or antipyretics on treatment days may help ameliorate flu-like symptoms associated with EXTAVIA use [see Warnings and Precautions (5.8)].

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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.