Perphenazine is used to treat certain mental/mood disorders (e.g., schizophrenia, manic phase of bipolar disorder, schizoaffective disorder). This medicine helps you to think more clearly, feel less nervous, and take part in everyday life. It can reduce aggressive behavior and the desire to hurt yourself/others. It may also help to decrease hallucinations (e.g., hearing/seeing things that are not there). Perphenazine is a psychiatric medication (antipsychotic-type) that works by helping to restore the balance of certain natural substances (e.g., dopamine) in the brain.
Take this medication by mouth, usually 1-3 times a day with or without food or as directed by your doctor. Dosage is based on your medical condition and response to therapy. Your doctor may direct you to take a low dose at first, gradually increasing the dose to lower the chance of side effects such as muscle spasms. Follow your doctor's directions carefully. When you begin treatment, frequent visits to your doctor may be needed to find the best dose for you. Keep all medical/lab appointments. Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day. Although you may notice some medication effects soon after starting, it may take as much as 4-6 weeks of regular use to see the full benefit. Do not stop taking this medication without consulting your doctor. Your condition may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased. Tell your doctor if your condition does not improve or if it worsens.
Drowsiness, constipation, dry mouth, dizziness, lightheadedness, blurred vision, tiredness, or unexplained weight gain may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position. 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. Some people using this medication do not have serious side effects. This drug may cause muscle/nervous system problems (extrapyramidal symptoms-EPS). Your doctor may prescribe another medication to decrease these side effects. Therefore, tell your doctor right away if you notice any of the following side effects: increased anxiety, drooling/trouble swallowing, restlessness/constant need to move, shaking (tremor), shuffling walk, stiff muscles. Tell your doctor right away if any of these unlikely but serious side effects occur: difficulty urinating. This medication may cause a condition known as tardive dyskinesia. In some cases, this condition may be permanent. Tell your doctor right away if you develop any involuntary/repetitive muscle movements such as lip smacking/puckering, tongue thrusting, chewing, or finger/toe movements. In rare cases, perphenazine may increase your level of a certain chemical made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped 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 right away. Tell your doctor right away if any of these rare but very serious side effects occur: easy bruising/bleeding, slow heartbeat, signs of infection (e.g., sore throat), severe muscle spasm/cramping (e.g., twisting neck, arching back, eyes rolling up), persistent nausea, seizures, stomach/abdominal pain, yellowing eyes/skin. Get medical help right away if you have any very serious side effects, including: fast/irregular heartbeat, severe dizziness, fainting. This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms: fever, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, signs of kidney problems (such as change in the amount of urine). A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: 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 or at www.fda.gov/medwatch.
Store at room temperature between 68-77 degrees F (20-25 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug are: certain drugs used for Parkinson's (e.g., bromocriptine, levodopa, pergolide), certain anticholinergic medications (e.g., dicyclomine, scopolamine), drugs affecting liver enzymes that remove perphenazine from your body (e.g., amiodarone, duloxetine, fluoxetine, paroxetine, ritonavir). Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: slow/shallow breathing, inability to wake up (coma).