Firdapse Side Effects

Generic name: amifampridine

Medically reviewed by Drugs.com. Last updated on Oct 1, 2023.

Note: This document contains side effect information about amifampridine. Some dosage forms listed on this page may not apply to the brand name Firdapse.

Applies to amifampridine: oral tablet.

Serious side effects of Firdapse

Along with its needed effects, amifampridine (the active ingredient contained in Firdapse) 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

Arm or leg pain
bladder pain
bloating or swelling of the face, arms, hands, lower legs, or feet
bloody or cloudy urine
blurred vision
burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
chest pain or tightness
chills
cough
cough producing mucus
diarrhea
difficult, burning, or painful urination
difficulty breathing or swallowing
dizziness
fever
frequent urge to urinate
general feeling of discomfort or illness
headache
hoarseness
joint pain
loss of appetite
lower back or side pain
muscle pains, spasms, or weakness
nausea
nervousness
pounding in the ears
rapid weight gain
runny nose
shivering
slow or fast heartbeat
sneezing
sore throat
sweating
swollen, painful, or tender lymph glands in the neck, armpit, or groin
trouble sleeping
unusual tiredness or weakness
unusual weight gain or loss
vomiting

Other side effects of Firdapse

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

Back pain
blindness
constipation
decreased vision
discouragement
falls
feeling cold
feeling sad or empty
heartburn
irritability
lack or loss of strength
loss of interest or pleasure
pale skin
stomach pain
trouble concentrating
trouble breathing
unusual bleeding or bruising

For Healthcare Professionals

Applies to amifampridine: oral tablet.

Hematologic

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

Immunologic

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

Musculoskeletal

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]

Ocular

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

Frequency not reported: Blurred vision^[Ref]

Metabolic

Common (1% to 10%): Peripheral edema

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

Psychiatric

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

Frequency not reported: Sleep disorders, anxiety^[Ref]

Genitourinary

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

Hepatic

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]

Respiratory

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]

Other

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]