Amantadine

Amantadine is a prescription medication used to treat Parkinson's disease, symptoms similar to Parkinson's disease, as well as used to treat drug-induced extrapyramidal reactions. It also is used to prevent and treat certain viral infections. Amantadine belongs to a class of drugs called antiviral agents, which stop the ability of the virus from spreading. It is not known how it works to treat Parkinson’s disease and similar conditions.

This medication comes in tablet, capsule, extended-release capsule, and syrup forms and is taken once or twice a day, with or without food.

Common side effects of amantadine include nausea, lightheadedness, and insomnia. Amantadine can also cause blurry vision. Do not drive or operate heavy machinery until you know how amantadine affects you.

Amantadine is a prescription medication used to treat patients with Parkinson's disease and who are being treated with levodopa and is used to treat symptoms similar to Parkinson's disease. Amantadine is used to treat drug-induced extrapyramidal reactions. It also is used to prevent and treat certain viral infections caused by a type of virus (influenza virus A).

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Amantadine may be found in some form under the following brand names:

• Gocovri

• Osmolex ER

• Symadine

• Symmetrel

Serious side effects have been reported with amantadine. See the “Amantadine Precautions” section

Common side effects of amantadine include the following:

• nausea
• lightheadedness
• insomnia
• depression
• anxiety and irritability
• hallucinations
• confusion
• anorexia
• dry mouth
• constipation
• loss of muscle coordination/control
• a netlike pattern of reddish-blue skin discoloration, usually on the legs
• swelling of arms, legs, or feet
• dizziness upon rising from a sitting position
• headache
• sleepiness
• nervousness
• abnormal dreams
• dry nose
• diarrhea
• fatigue

This is not a complete list of amantadine side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• triamterene/hydrochlorothiazide (Dyazide)
• quinine or quinidine
• central nervous system stimulants such amphetamine/dextroamphetamine (Adderall), methylphenidate (Concerta, Methylin, Ritalin, Metadate), dexmethylphenidate (Focalin), and lisdexamfetamine (Vyvanse).
• anticholinergics such as glycopyrrolate (Cuvposa, Robinul), trospium (Sanctura), oxybutynin (Anturol, Gelnique, Oxytrol, Ditropan), solifenacin (Vesicare), dicyclomine (Bentyl), propantheline (Pro-Banthine), and atropine (Atropen, Sal-Tropine)
• phenothiazines such as chlorpromazine (Thorazine), thioridazine (Mellaril), fluphenazine (Prolixin), perphenazine (Triavil), prochlorperazine (Compazine), and trifluoperazine (Stelazine)
• drugs that affect urine pH such acetazolamide and sodium bicarbonate

This is not a complete list of amantadine drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with amantadine including the following:

• Neuroleptic Malignant Syndrome (NMS). Tell your healthcare provider right away if you have some or all of the following symptoms of NMS.
  • fever
  • loss of muscle control
  • change in mental status
  • increased heart or breathing rate
• Melanoma. Patients with Parkinson's disease have a higher risk of developing this serious form of skin cancer and should be monitored routinely by a dermatologist.
• Impulse Control/Compulsive Behaviors. Patients treated with amantadine can experience intense urges (sexual, gambling, spending money uncontrollably).
• Excessive drowsiness and falling asleep during the daytime.
• Hallucinations or psychotic behavior. Patients treated with amantadine should be observed for these side effects.
• Depression and suicidal thoughts. Patients treated with amantadine should be monitored for these side effects.
• Low blood pressure. Low blood pressure may cause you to feel faint or dizzy. Inadequate fluid intake, excessive sweating, diarrhea, or vomiting can lead to an excessive fall in blood pressure too. Lie down if you feel faint or dizzy. Call your doctor right away.
• Fever and confusion upon sudden discontinuation. Do not stop amantadine suddenly. Talk to your doctor about how to stop amantadine. 

Amantadine can cause drowsiness. Do not drive or operate heavy machinery until you know how amantadine affects you.

Do not take amantadine if you:

• are allergic to amantadine or to any of its ingredients.
• have severe kidney problems. 

While taking amantadine: 

• Do not drive, operate machinery, or do other dangerous activities until you know how amantadine affects you
• Do not drink alcohol as it can increase your chances of serious side effects
• Do not stop or change the dose of amantadine before talking with your doctor. Call your healthcare provider if you have symptoms of withdrawal such as fever, confusion, or severe muscle stiffness
• Do not take a flu nasal spray, but you can receive a flu shot

Live vaccines are not recommended while taking amantadine. Amantadine may affect how well the live vaccines work.

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of amantadine, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking amantadine, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to amantadine or to any of its ingredients
• have epilepsy or a history of seizures
• have liver problems
• have kidney problems especially in patients older than 65 years
• have heart problems such as congestive heart failure
• have swelling of the arms, legs, or feet
• have untreated vision problems such as angle closure glaucoma
• have daytime sleepiness or a sleep disorder
• take any medications to help you sleep or that make you drowsy
• have any mental health problems such as depression or hallucinations
• drink alcoholic beverages
• have or have had urges such as gambling, increased sex drive, or compulsive shopping or eating
• have or have had psychotic behavior issues
• are pregnant or breastfeeding

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Amantadine falls into category C. In animal studies, pregnant animals were given this medication and had some babies born with problems. No well-controlled studies have been done in humans. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.

Tell your doctor if you are breastfeeding or plan to breastfeed.

Amantadine has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants, the use of amantadine is not recommended.Your doctor and you will decide if the benefits outweigh the risk of using amantadine.

Take amantadine exactly as prescribed. 

This medication comes in tablet, capsule, and syrup forms and is taken once or twice a day.  

It also comes in extended-release (long-acting) capsules and tablets that are taken once a day. Do not chew, divide, or break extended-release capsules and tablets. Swallow extended-release capsules and tablets whole. 

Take with or without food. 

Alcohol may intensify some of the side effects (dizziness, light-headedness, confusion) of this medication.

Do not stop this medication abruptly.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of amantadine at the same time.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• your kidney function
• your age
• your weight

Prevention and treatment of uncomplicated influenza A virus

The recommended adult dose of amantadine for the prevention and treatment of uncomplicated influenza A virus is 200 mg in a single dose and is given within 24-48 hours after onset of symptoms and continued 24-48 hours after symptoms disappear.

In persons 65 years of age or older, the daily dosage of amantadine is 100 mg.

Pediatric Patients:

• 1 yr-9 yrs of age: The total daily dose is calculated using 4.4 to 8.8 mg/kg/day and is divided into two doses (Should not exceed 150 mg per day)
• 9 yrs-12 yrs of age: The recommended dose is 100 mg twice a day.

Parkinson's disease

The recommended adult dose of amantadine tablets and liquid for the treatment of Parkinson's disease or symptoms similar to Parkinson's disease is 100 mg twice a day when used alone.

The initial dose of amantadine is 100 mg daily for patients with serious associated medical illnesses or who are receiving high doses of other antiparkinson drugs. After one to several weeks, the dose may be increased to 100 mg twice daily, if needed.

The recommended starting dose of Gocovri (amantadine) extended-release capsules is 137 mg by mouth once daily at bedtime. After 1 week, it is recommended that the dose is increased to 274 mg once daily at bedtime. People with lower kidney function may require lower doses.

The recommended starting dose of Osmolex ER (amantadine) extended-release tablets is 129 mg by mouth once a day in the morning. The maximum dose is 322 mg per day. 

Dosage for Drug-Induced Extrapyramidal Reactions:

If you take too much amantadine, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

• Store amantadine at room temperature in a light-resistant container.
• Keep away from heat and sunlight.
• Keep this and all medicines out of the reach of children.
• Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to amantadine.