Multiple sclerosis Avonex protocol and monitorin
Interferon beta-1a is administered intramuscularly weekly for MS, starting with a quarter dose, increasing to 30 μg. Side effects include flu-like symptoms, liver dysfunction, and blood cell changes. Monitoring involves regular blood tests, liver function, and checking for neutralizing antibodies. Discontinue for severe side effects or pregnancy.
2024-01-06 06:18:37 - Editor
Interferon Beta-1a (Avonex) Treatment for Multiple Sclerosis
Dosage & Titration Schedule:
Interferon beta-1a dose is 30 micrograms (0.5 ml solution), administered by intramuscular (IM) injection once weekly.
Avonex Titration Schedule (intramuscular injection):
Week 1: 1/4 dose (approximately 7.5 μg)
Week 2: 1/2 dose (approximately 15 μg)
Week 3: 3/4 dose (approximately 22.5 μg)
Week 4+: Full dose (30 μg) and every week thereafter
Side Effects:
Side effects: Common side effects of interferon beta (INFB) therapy include injection site reactions, headache and flu like symptoms. Also, there is a high prevalence of asymptomatic, mild liver dysfunction associated with IFNB therapy. Leukoneutropenia and anemia can also occur. Vomiting and diarrhae is common with INFB. Finally, rare cases of thrombotic microangiopathy have been linked to the use of IFNB therapy. INFB is contraindicated in patients with depressive disorders or those with history of seizures. (1, 2)
Monitoring:
Before Initiation of Therapy:
CBC, bilirubin, liver enzymes, TSH
HBsAg, anti-HBs, anti-HBc, Hepatits C, HIV, VZV serology
Vaccination status verified and updated,
Negative pregnancy test and counsel with regards to contraception
Monitoring During therapy:
CBC, bilirubin, Liver enzymes every month for 6months then then every 6 months
TSH every 6months
Premedication for Flu-like Symptoms with analgesics and/or antipyretics on treatment days to help ameliorate flu-like symptoms.
Monitoring for neutralizing antibodies after 1st year including neutralizing antibodies (NAbs) and myxovirus resistance protein A (MxA) are investigational. The development of such antibodies can limit the effectiveness of INFB.
If leukopenia develops or transaminases three times above normal then, it is advisable to decrease the IFNB dose by 50% or consider switching to another DMT if indicated.
Discontinuation Criteria:
ALT over 5times above normal level ;
Severe leukopenia or pancytopenia, severe thrombocytopenia;
Seizure;
Pregnancy;
or If Nabs +ve.
(3, 4, 5, 6, 7)
References
1- Panitch H, Goodin DS, Francis G, Chang P, Coyle PK, O’Connor P, Monaghan E, Li D, Weinshenker B EVIDENCE Study Group. EVidence of Interferon Dose-response: Europian North American Compartative
Efficacy; University of British Columbia MS/MRI Research Group. Randomized, comparative study of interferon β-1a treatment regimens in ms the evidence trial. Neurology. 2002;59:1496–1506.
2-Calabresi PA, Kieseier BC, Arnold DL, et al. Pegylated interferon β-1a for relapsing-remitting multiple sclerosis (ADVANCE): a randomised, phase 3, double-blind study. Lancet Neurol 2014; 13:657.
3- Gama HP, Rocha AJ, Silva CJ, Mendes MF, Veiga JC, Lancellotti CL, Andrade VP, Tilbery CP. Meningioma growth during interferon beta-1A treatment for multiple sclerosis. Arq Neuropsiquiatr. 2008;66:402–4.
4-Jacobs LD, Cookfair DL, Rudick RA, et al. Intramuscular interferon beta-1a for disease progression in relapsing multiple sclerosis. The Multiple Sclerosis Collaborative Research Group (MSCRG). Ann Neurol 1996; 39:285.
5-Bertolotto A, Gilli F, Sala A, et al. Persistent neutralizing antibodies abolish the interferon beta bioavailability in MS patients. Neurology 2003; 60:634.
6-Goodin DS, Frohman EM, Hurwitz B, et al. Neutralizing antibodies to interferon beta: assessment of their clinical and radiographic impact: an evidence report: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 2007; 68:977.
7-Kasper LH, Reder AT. Immunomodulatory activity of interferon-beta. Ann Clin Transl Neurol 2014; 1:622.