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Amifampridine Side Effects

Medically reviewed by Last updated on Jun 13, 2023.

Applies to amifampridine: oral tablet.

Serious side effects of Amifampridine

Along with its needed effects, amifampridine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking amifampridine:

More common

Other side effects of Amifampridine

Some side effects of amifampridine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to amifampridine: oral tablet.


Common (1% to 10%): Lymphadenopathy[Ref]


Common (1% to 10%): Viral infection[Ref]


Very common (10% or more): Back pain (14%), muscle spasm (12%), muscle weakness (10%), pain in extremity (10%)

Common (1% to 10%): Blood creatine phosphokinase increased[Ref]


Very common (10% or more): Cataract (10%)

Frequency not reported: Blurred vision[Ref]


Common (1% to 10%): Peripheral edema

Uncommon (0.1% to 1%): Hypercholesterolemia[Ref]


Common (1% to 10%): Insomnia, depression

Frequency not reported: Sleep disorders, anxiety[Ref]


Common (1% to 10%): Urinary tract infection[Ref]


Very common (10% or more): Elevated liver enzymes (e.g., elevated alanine aminotransferase [ALT], aspartate aminotransferase [AST], lactate dehydrogenase [LDH], gamma-glutamyl transferase [GGT] (14%)

transferase (GGT)[Ref]


Very common (10% or more): Upper respiratory tract infection (33%)

Common (1% to 10%): Bronchitis, dyspnea, influenza

Frequency not reported: Bronchial hypersecretion, asthma attack in asthmatic patients or patients with a history of asthma, cough[Ref]


Common (1% to 10%): Fall, pyrexia[Ref]

Nervous system

Very common (10% or more): Paresthesia/dysesthesia (i.e., oral paresthesia, oral hypoesthesia) (69%), headache (14%), dizziness (10%), asthenia (10%)

Common (1% to 10%): Seizures[Ref]


Very common (10% or more): Hypertension (12%)

Frequency not reported: Raynaud's syndrome, cardiac rhythm disorders, palpitations[Ref]


Very common (10% or more): Hyperhidrosis, cold sweat

Common (1% to 10%): Erythema[Ref]


Very common (10% or more): Abdominal pain (14%), nausea (14%), diarrhea (14%), dyspepsia (17%)

Common (1% to 10%): Constipation, GI reflux

Frequency not reported:: Epigastralgia[Ref]

Frequently asked questions


1. Product Information. Firdapse (amifampridine). Catalyst Pharmaceuticals, Inc. 2018.

2. Product Information. Ruzurgi (amifampridine). Medunik Canada. 2021.

Further information

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

Some side effects may not be reported. You may report them to the FDA.