Side Effects
Drowsiness, lethargy, dizziness, nausea, loss of appetite, sweating, dry mouth, blurred vision, headache, constipation, or pain/redness at the injection site may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor immediately if any of these unlikely but serious side effects occur: feelings of restlessness, mask-like facial expression, greatly increased saliva, tremors, unusual mental/mood changes (e.g., depression, worsening of psychosis), confusion, unusual dreams, frequent urination or difficulty urinating, vision problems, weight change, swelling of the feet/ankles, fainting, skin discoloration. Tell your doctor immediately if any of these rare but very serious side effects occur: butterfly-shaped facial rash, joint/muscle pain, seizures. In rare instances, this medication may increase your level of a certain hormone (prolactin). For females, this rare increase in prolactin may result in unwanted breast milk, missing/stopped menstrual periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor immediately. For males, in the very unlikely event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and seek immediate medical attention, or permanent problems could occur. Fluphenazine may rarely cause a condition known as tardive dyskinesia. In some cases, this condition may be permanent. Tell your doctor immediately if you develop any unusual/uncontrolled movements (especially of the face, mouth, tongue, arms, or legs). This medication may rarely cause a serious condition called neuroleptic malignant syndrome (NMS). Seek immediate medical attention if you develop the following: fever, muscle stiffness, severe confusion, increased sweating, fast or irregular heartbeat. This drug may infrequently cause serious blood problems (e.g., agranulocytosis, leukopenia) or liver problems. Seek immediate medical attention if you notice any of the following rare but very serious side effects: signs of infection (e.g., fever, persistent sore throat), easy bruising/bleeding, severe stomach/abdominal pain, dark urine, yellowing of the eyes/skin. A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.