Amifampridine oral
- Drugs List
- Therapeutic Indications
- Dosage
- Contraindications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
- Monograph
Presentation
Oral formulation of amifampridine.
Drugs List
Therapeutic Indications
Uses
Myasthenic Eaton-Lambert syndrome
Dosage
Adults
Starting dose
15mg daily in divided doses three or four times a day. This can be increased in 5mg increments every 4 to 5 days, up to a maximum of 60mg per day. Maximum single dose 20mg.
Patients with Renal Impairment
Moderate to severe renal impairment
Starting dose: 5mg daily.
Mild renal impairment
Starting dose: 5mg twice a day.
Titrate slowly with doses increased in 5mg increments every 7 days.
If any adverse reaction occurs, upward dose titration should be discontinued.
Patients with Hepatic Impairment
Moderate to severe hepatic impairment
Starting dose: 5mg daily.
Mild hepatic impairment
Starting dose: 5mg twice a day.
Titrate slowly with doses increased in 5mg increments every 7 days.
If any adverse reaction occurs, upward dose titration should be discontinued.
Contraindications
Children under 18 years
Breastfeeding
Epileptic disorder
Long QT syndrome
Pregnancy
Torsade de pointes
Uncontrolled asthma
Precautions and Warnings
Family history of long QT syndrome
Females of childbearing potential
Predisposition to epileptic disorder
Electrolyte imbalance
Hepatic impairment
History of asthma
History of torsade de pointes
Renal impairment
Correct electrolyte disorders before treatment
Reduce dose and/or alter dose interval in patients with hepatic impairment
Reduce dose and/or alter dose interval in patients with renal impairment
Advise ability to drive/operate machinery may be affected by side effects
Treatment to be initiated and supervised by a specialist
Assess patient for predisposing risk factors which lower seizure threshold
Discontinue treatment if patient develops seizures
Monitor patients with hepatic impairment
Monitor patients with renal impairment
Monitor serum electrolytes
Perform ECG when initiating treatment and yearly thereafter
Predisposition QT prolongation: Counsel patient on symptoms of arrhythmias
Discontinue at first sign of arrhythmia - perform ECG
Male & female: Ensure adequate contraception during treatment
The use of amifampridine in patients with the non-paraneoplastic form of LEMS should only be commenced following a thorough assessment of the risk-benefit to the patient.
Schwannoma should be considered for patients who present with symptoms such as a mass that is painful on palpation or similar symptoms to a compressive neuropathy. Treatment with amifampridine should be reviewed if any patient develops a Schwannoma. Caution is advised in patients at risk of Schwannomas, such as a past medical history of such tumours, neurofibromatosis Type 2 or schwannomatosis.
Pregnancy and Lactation
Pregnancy
Amifampridine is contraindicated during pregnancy.
Use of amifampridine during pregnancy is contraindicated by the manufacturer. Animal studies have shown teratogenic effects. Human data is limited and as such a potential risk cannot be ruled out.
Lactation
Amifampridine is contraindicated during breastfeeding.
The manufacturer advises that the patient either discontinues amifampridine or discontinues breastfeeding. Animal data reports significant levels of amifampridine in the breast milk, however presence in human breast milk is unknown.
Side Effects
Abdominal pain
Aggravation of existing asthma
Anxiety
Blurred vision
Cardiac arrhythmias
Chorea
Cold extremities
Cold sweat
Convulsions
Cough
Diarrhoea
Dizziness
Drowsiness
Fatigue
Gastralgia
Headache
Hyperhidrosis
Hypoaesthesia
Increase of liver transaminases
Increased bronchial secretions
Myoclonus
Nausea
Palpitations
Paraesthesia
Prolongation of QT interval
Raynaud's syndrome
Sleep disturbances
Weakness
Overdosage
It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.
The following number will direct the caller to the relevant local centre (0844) 892 0111
Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Further Information
Last Full Review Date: November 2020
Reference Sources
NICE Evidence Services Available at: www.nice.org.uk Last accessed: 21 August 2019
Summary of Product Characteristics: Firdapse 10mg tablets. BioMarin Europe Ltd. Revised August 2019.
Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content
FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.