Istradefylline (Oral route)
Uses of This Medicine:
Istradefylline is used with levodopa and carbidopa to treat adults with Parkinson’s disease who are having “off” episodes.
This medicine is available only with your doctor's prescription.
Before Using This Medicine:
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of istradefylline in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of istradefylline in the elderly.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- St John's Wort
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems—
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Dyskinesia (abnormal muscle movements) or
- Psychosis (mental disorder), or history of—Use with caution. May make these conditions worse.
- Liver disease, moderate or
- Patients who are smoking tobacco—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper Use of This Medicine:
Take this medicine exactly as directed. Do not stop taking your medicine unless ordered by your doctor. It is also important to not start taking other medicines for your Parkinson's disease without first talking with your doctor.
This medicine usually comes with patient information leaflet. Read the instructions carefully and make sure you understand them before taking this medicine. If you have any questions, ask your doctor.
You may take this medicine with or without food.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For Parkinson's disease:
- Adults—20 milligrams (mg) once a day, Your doctor may increase your dose as needed and tolerated. However, the dose is usually not more than 40 mg per day.
- Children—Use and dose must be determined by your doctor.
- For Parkinson's disease:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions While Using This Medicine:
It is very important that your doctor check your progress at regular visits to allow changes in your dose and to check for any unwanted effects.
This medicine may cause uncontrolled sudden movements (dyskinesia) or make such movements you already have worse or more frequent. Tell your doctor if this happens.
If you develop any unusual or strange thoughts and behavior while using this medicine, be sure to discuss it with your doctor. Other changes might be confusion, delusion (believing things that are not real), hallucinations (seeing or hearing things that are not there), getting paranoid, suicidal thoughts, and unusual excitement, nervousness, or irritability.
Some people who have used this medicine had unusual changes in their behavior. Talk with your doctor right away if you start having problems with gambling or an increased interest in sex while using this medicine.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.
Side Effects of This Medicine:
- More common
- Seeing, hearing, or feeling things that are not there
- twitching, twisting, uncontrolled repetitive movements of tongue, lips, face, arms, or legs
- Less common
- Actions that are out of control
- attack, assault, force
- confusion as to time, place, or person
- delusions of persecution, mistrust, suspiciousness, or combativeness
- dry mouth
- false beliefs that cannot be changed by facts
- increased sexual urges
- irregular heartbeats
- shortness of breath
- talking, feeling, and acting with excitement
- trouble sleeping
- unusual excitement, nervousness, or restlessness
- More common
- Difficulty having a bowel movement (stool)
- Less common
- Decreased appetite
Along with its needed effects, a medicine 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:
Some side effects 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:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Last Updated: 6/10/2021