Fluphenazine: Administration, Side Effects, Precautions, Interactions and Storage

It belongs to a class of drugs called phenothiazines, is an antipsychotic, and is also known as a neuroleptic.

This drug is commonly used to treat certain mental disorders such as schizophrenia; its operation consists of affecting some natural chemical substances in the body, such as neurotransmitters in the brain, which cause mental imbalance.

Some of the benefits of continued use of this drug include reduced episodes of hallucinations, delusions, or strange behaviors in patients with schizophrenia.

Fluphenazine differs from other phenothiazine derivatives in several ways:

It is more potent in milligrams, has a less potentiating effect on central nervous system depressants and anesthetics than some phenothiazines, appears to be less sedating, and is less likely than some of the older phenothiazines to produce hypotension.

Chemical formula



It comes as injections for parental use.


It is available as a clear, pale yellow solution for intramuscular or subcutaneous use that provides 25 mg of fluphenazine decanoate per ml in a sesame oil vehicle with 12 mg of benzyl alcohol as a preservative.


This drug can have adverse effects on the efficient functioning of neurotransmitters if the patient does not have an actual condition that warrants its use, so it must be prescribed by a specialist doctor to be ingested.

Its consumption with food is recommended if the patient has stomach upset unless the treating physician indicates otherwise.

Fluphenazine mustn’t be consumed or diluted with coffee or caffeine beverages.

Typically, it is mixed with 4 ounces of caffeine-free carbonated beverages, natural juices, milk, or drinking water.

Due to the effects it generates in the cerebral nervous system, it cannot be suspended without the prior indication of the specialist doctor. Otherwise, it can cause an unwanted emotional or neuronal imbalance that can threaten the patient’s life.

Even affect the behavior of the affected person so that they can attack or violate their relatives.

Everyone who must take Fluphenazine must know that an average of at least two weeks must elapse for it to take effect, so they must be patient and not be alarmed if they feel or believe that there is no improvement in their mental health.


Fluphenazine is a long-acting parenteral antipsychotic drug intended to treat patients requiring prolonged neuroleptic therapy, such as chronic schizophrenics.

Mechanism of action

Fluphenazine is active at all levels of the central nervous system and multiple organ systems.

The mechanism by which its therapeutic action is exerted is unknown.

Side effects

Due to the type of drug that is Fluphenazine, it can cause various side effects, including:

  • Constant dizziness
  • Loss of appetite
  • Nausea or vomiting
  • Drowsiness or lethargy
  • Headaches or chronic migraine.
  • Difficulty focusing on objects at short or long distances.
  • Excessive sweating

If the dose prescribed by the doctor is too high for the patient, the following symptoms may appear that can be harmful or excessively uncomfortable for the patient:

  • Unusual mood swings can lead to chronic depression or psychosis.
  • Severe visual problems
  • Difficulty urinating or excess urine makes it challenging to control the sphincters.
  • Confusion or disorientation
  • Restlessness or feeling restless.
  • Swelling in the feet and ankles.
  • Involuntary weight change
  • Body tremors
  • Weird or unusual dreams.
  • Seizures
  • Rash on the skin, especially on the face.
  • Joint pain
  • Sudden change in skin tone, acquiring a pale color.

In the case of women, Fluphenazine could. However, it is rare to alter a hormone called prolactin, which can generate the sudden production of breast milk, and lack of control in the menstrual period. It could even decrease or stop and difficulty of getting pregnant.

For men, it may make it difficult to get an erection, be painful, or have it for 4 hours or more, leading to future problems. If this happens, the patient should immediately contact his treating physician.

This medicine does not usually affect or cause severe problems in the blood or cause severe allergic reactions. However, anyone who is being treated with Fluphenazine and presents the following symptoms should contact their treating doctor:

  • Difficulty breathing.
  • Bleeding from the nose or other mucus.
  • Swelling of the face, tongue, or throat.
  • Itching in the extremities of the body.
  • Cardiac arrhythmia.
  • Elevated body temperature
  • Redness of the face.
  • The appearance of hives or rash on the body.
  • Severe dizziness


For most patients, a dose of 12.5 to 25 mg (0.5 to 1 mL) can be given to initiating treatment.

The onset of action generally appears between 24 and 72 hours after injection, and the effects of the drug on psychotic symptoms become significant within 48 to 96 hours.

Subsequent injections and the dosing interval are determined according to the patient’s response.

A single injection can effectively control schizophrenic symptoms for up to four weeks or more when given as maintenance therapy.

The response to a single dose has been found to last up to six weeks in some patients on maintenance therapy.


This drug is usually very aggressive, which implies sudden mood changes, so its use is not recommended in children under 12 years of age.

The specialist doctor must know the patient’s history and if he has presented problems in the nervous system, brain damage, liver problems, heart problems, kidney problems, or any other condition that could modify the treatment dose.

Patients treated with Fluphenazine should avoid consuming alcoholic beverages or the use of marijuana because it can cause sudden changes, increased feelings of paranoia or psychosis, and increased anxiety levels.

This medicine can make some people more sensitive to the sun’s rays, so exposure to it should be avoided without caution, and the use of tanning booths or lamps should be eliminated.

Fluphenazine can impair the normal process of pregnancy, so it should only be ingested in strictly necessary cases. If the patient is breastfeeding, she should ask her doctor if she can continue the treatment, as it may affect the baby.

This medication should not be used without notifying the doctor that a baby is being breastfed, as it is not known whether Fluphenazine passes into breast milk.

Fluphenazine interactions

Cold or allergy medications, sedatives, narcotic pain relievers, sleeping pills, muscle relaxers, and seizure medications.

Depression or anxiety can interact with Fluphenazine and cause medical problems or increase side effects.

Fluphenazine can have adverse effects to those desired if it is ingested with other drugs, so it is recommended that the treating physician be told all the medications that the patient is using to avoid future inconveniences.

Patients cannot exceed the dose prescribed by the specialist because they can get an overdose, which would harm their health and even lead to death.

If the affected person presents the following symptoms, they should immediately contact their doctor or go to the nearest health center:

  • Disorientation.
  • Difficulty distinguishing where you are.
  • Excessive sweating
  • Nausea, vomiting, and dizziness.
  • Fainting and lightheadedness.
  • High or low body temperature.
  • Slowing down or speeding up the heartbeat
  • Difficulty breathing.

The doctor should be informed if you regularly use any of these medications:

  • Atropine.
  • Lithium.
  • Antibiotics
  • Birth control pills or hormone replacement estrogens.
  • Blood pressure medicine.
  • Blood thinners such as warfarin.
  • Incontinence medications.
  • Medications for diabetes are taken by mouth.
  • Medicines for nausea, vomiting, or dizziness.
  • Drugs to treat or prevent malaria.
  • Drugs are used to prevent organ transplant rejection.
  • A stimulant or medication for ADHD.
  • Irritable bowel ulcer or medications.
  • Medicines to treat Parkinson’s disease, restless legs syndrome, or pituitary gland tumor (prolactinoma).

Warnings and Contraindications

Fluphenazine can impair thinking or reactions. Care must be taken when driving or doing anything that requires alertness.

You should avoid getting up too fast when sitting or lying down, or you may feel dizzy, to stabilize yourself to prevent falls.

This medication should be stopped immediately, and a doctor should be called if there are twitching or uncontrollable movements of the eyes, lips, tongue, face, arms, or legs.

Fluphenazine should not be used in psychotic conditions related to dementia.

This drug can cause heart failure, sudden death, or pneumonia when given to older adults with dementia-related conditions.

Fluphenazine should not be used if you have liver disease, brain damage, bone marrow depression, a blood cell disorder, or if you are also consuming large amounts of alcohol or medications that make you drowsy.

Fluphenazine should not be used if the patient is allergic to Fluphenazine or other phenothiazines.

You should not give Fluphenazine if you have heart disease or high blood pressure, a history of seizures, Parkinson’s disease, or liver or kidney disease.

Severe asthma or a breathing problem, a past or present breast cancer, an adrenal gland tumor, an enlarged prostate, problems urinating, glaucoma, or low calcium levels in the blood.

If you have ever had a severe side effect while using Fluphenazine or similar medicines.

Symptoms such as withdrawal, respiratory system problems, eating problems, irritability, tremors, and muscle flaccidity or stiffness have been reported.

Since there is no adequate experience in children who have received this medicine, the safety and efficacy in children have not been established.

Stopping this medicine may cause withdrawal symptoms or other problems; do not stop taking it without a doctor’s prescription.


Fluphenazine should be stored in spaces free from moisture and heat; it does not need to be refrigerated and kept at room temperature.

Contact with children or pets should be avoided because their unsupervised consumption can cause harmful or counterproductive effects on the health of those affected.