Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Abnormal heart rhythm: This medication may cause or increase the risk for a certain type of abnormal heart rhythm called QT prolongation. Other medications can also increase the risk of QT prolongation when taken together with fluphenazine decanoate. If you experience symptoms of an abnormal heart rhythm such as dizziness, heart palpitations (fast, pounding, or irregular heartbeat), fainting, or seizures, stop taking this medication and get immediate medical attention.
Blood counts: This medication can decrease the number of neutrophils (a type of white blood cell that helps fight infection) and platelets (which help your blood to clot). Your doctor will do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.
Drowsiness/reduced alertness: Especially in the first few days of treatment, this medication may impair the mental and physical abilities required for driving a car or operating heavy machinery. Avoid these activities until you know this medication does not affect your ability to perform them safely. Avoid drinking alcohol while using this medication, as it can produce extreme drowsiness.
Heat exposure and sweating: Fluphenazine decanoate may prevent the body from cooling when overheated by reducing your ability to sweat. Avoid becoming overheated when using fluphenazine decanoate.
Involuntary movement: Like other medications to control symptoms of schizophrenia, fluphenazine decanoate may cause rhythmic involuntary movements, known as tardive dyskinesia. Tardive dyskinesia is more likely to occur in women and seniors. These movements may involve only the tongue, face, mouth, or jaw, or they may include the extremities and trunk. Tardive dyskinesia is not reversible for some people. Report involuntary movements including sticking out the tongue, puckering mouth, or chewing movements to your doctor as soon as possible.
Kidney function: Fluphenazine decanoate may cause decreased kidney function and should not be used by people with kidney disease. Your doctor may want to regularly monitor your kidney function with blood tests when you first start taking fluphenazine decanoate to monitor for reduced kidney function.
Liver problems: Fluphenazine decanoate may cause liver problems. Your doctor may want to test your liver function with blood tests regularly while you are taking this medication. If you notice any signs of liver problems such as yellowing of the skin or whites of the eyes, nausea, vomiting, diarrhea, loss of appetite, weight loss, dark urine, or pale stools, contact your doctor as soon as possible.
Low blood pressure: This medication can cause low blood pressure. If you have heart disease, disorders of the blood vessels in the brain, or are having surgery, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Neuroleptic malignant syndrome: Very rarely, fluphenazine decanoate has been reported to cause a severe reaction called neuroleptic malignant syndrome. If you or someone in your family who is being given fluphenazine decanoate develops symptoms including high body temperature (above 38°C), sweating, rapid heartbeat, severe muscle stiffness, and change in alertness, seek emergency help immediately.
Seizure disorders: Seizures have been reported by people who are taking fluphenazine decanoate. If you have seizure disorders, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Sun: This medication makes you more sensitive to the harmful effects of sunlight.
Tremor and stiffness: As with other medications used to treat schizophrenia, fluphenazine decanoate may cause tremors or stiffness, or difficulty beginning purposeful movement. If this occurs, report it to your doctor as soon as possible.
Vision changes: Fluphenazine decanoate has been reported to cause changes in vision. Tell your doctor about any changes as soon as possible.
Withdrawal: Suddenly stopping this medication can cause withdrawal symptoms such as nausea, vomiting, dizziness, and shaking. Do not stop using this medication unless recommended by your doctor.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if fluphenazine decanoate passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of this medication have not been established for children.
Seniors: Seniors with dementia may be more at risk of stroke and mini-strokes while using this medication. They are also more likely to experience side effects. Smaller doses of this medication are usually needed for seniors.