What is fluphenazine, and what is it used for?

Fluphenazine is a first generation antipsychotic medication used for symptomatic management of psychotic disorders in patients with chronic schizophrenia who require prolonged therapy.

First generation antipsychotics are less commonly prescribed after the advent of second generation antipsychotics which are more effective in treating the negative symptoms of schizophrenia and have better safety profiles.

Fluphenazine works by reducing the activity of dopamine, a chemical (neurotransmitter) released in the brain by nerve cells (neurons) to transmit signals. Dopamine has many functions including regulation of movement, memory, motivation, and pleasure. Overactivity of dopamine in certain pathways of the brain appears to lead to positive symptoms of schizophrenia such as hallucinations and delusions.

Fluphenazine belongs to a group of antipsychotics derived from a compound known as phenothiazine. Fluphenazine inhibits dopamine activity by blocking dopamine D1 and D2 receptors, protein molecules on neurons that respond to dopamine and initiate excitatory action. Fluphenazine also depresses the release of hormones by the hypothalamus and pituitary gland, which results in its side effects.

The limitation of fluphenazine is that it does not have efficacy in the management of behavioral complications in patients with intellectual disabilities. Fluphenazine is used off-label in the management of Tourette syndrome that causes involuntary muscle twitches (tics) and unintended sounds (phonic tics).

What are the side effects of fluphenazine?

Common side effects of fluphenazine include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

What are the dosages of fluphenazine?

Tablet

• 1 mg
• 2.5 mg
• 5 mg
• 10 mg

Elixir

• 2.5 mg/5 mL

Oral concentrate

Injectable solution

• 2.5 mg/mL (fluphenazine hydrochloride)
• 25 mg/mL (fluphenazine decanoate)

Adult:

Psychotic Disorders

Fluphenazine hydrochloride

• 2.5-10 mg/day orally divided every 6-8 hours initially; maintenance: 1-5 mg orally/intramuscularly divided every 6-8 hours; not to exceed 40 mg/day

Fluphenazine decanoate

• 12.5-25 mg (25 mg/mL) intramuscularly/subcutaneously (IM/SC) every 2-4 weeks

Dosing considerations

• Conversion from hydrochloride salt to decanoate: 10 mg/day orally HCl salt = approximately 12.5 mg intramuscularly/subcutaneously (IM/SC) every 3 weeks of decanoate salt

Dosing Modifications

• Renal impairment: Use with caution; monitor
• Hepatic impairment: Use with caution; monitor

Geriatric:

• 1-2.5 mg/day orally; dosage titrated according to response

Pediatric:

• Safety and efficacy not established

Overdose

• Fluphenazine overdose can cause symptoms such as dry mouth, reduced sweating, urinary retention, constipation, increased heart rate, dilated pupils, and blurred vision.
• There is no specific antidote for fluphenazine, overdose is treated with symptomatic and supportive care.

What drugs interact with fluphenazine?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Severe interactions of fluphenazine include: 
• Fluphenazine has serious interactions with at least 91 different drugs.
• Fluphenazine has moderate interactions with at least 339 different drugs.
• Fluphenazine has mild interactions with at least 59 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

Pregnancy and breastfeeding

• Fluphenazine treatment during pregnancy should be individualized and used only if clearly needed, based on benefits of treatment to the mother and potential risks to the mother and fetus.
• Antipsychotic use during the third trimester of pregnancy has a risk for abnormal muscle movements (extrapyramidal symptoms) and/or withdrawal symptoms in newborns following delivery.
• Fluphenazine is present in breast milk, avoid use in nursing mothers.

What else should I know about fluphenazine?

• Take fluphenazine exactly as prescribed.
• Fluphenazine can cause movement disorders, particularly with prolonged therapy. Notify your physician if you develop symptoms such as muscle twitches or tightness.
• Report immediately to your physician if you develop flu-like illness, fever, lethargy, weakness or infections.
• Fluphenazine may impair body temperature regulating mechanism. Exercise caution to avoid overexercising, dehydration and getting exposed to extreme cold or heat.
• Fluphenazine is associated with risks of drowsiness and seizure. Avoid potentially hazardous activities such as driving or operating heavy machinery while on therapy.
• Store safely away from the reach of children.
• In case of overdose, seek medical help immediately or contact Poison Control.