Before taking perphenazine, tell your doctor or pharmacist if you are allergic to it, or to other phenothiazines (e.g., chlorpromazine, fluphenazine), or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: decreased bone marrow function, serious head injury, severe liver problems, severe nervous system problem (e.g., coma, drug/alcohol overdose, shock), Parkinson’s disease.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: history of alcohol/substance abuse, low blood pressure, breathing problems (e.g., asthma, emphysema), breast cancer, fast/slow/irregular heartbeat, heart valve problems, a certain adrenal gland tumor (pheochromocytoma), restless legs syndrome, seizure disorder, a certain severe reaction to other medications (neuroleptic malignant syndrome), difficulty urinating (e.g., due to prostate problems).
This drug may make you dizzy or drowsy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Avoid alcoholic beverages.
To reduce dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
This medication may make you more sensitive to the sun. Avoid prolonged sun exposure, tanning booths, and sunlamps. Use a sunscreen and wear protective clothing when outdoors.
Before having surgery, tell your doctor or dentist that you are taking this medication.
Caution is advised during hot weather because perphenazine can reduce sweating, increasing your risk for a severe reaction to too much heat (heatstroke). Drink plenty of fluids. Avoid strenuous exercise in hot weather. If you become overheated, promptly seek cooler shelter and/or stop exercising. Seek immediate medical attention if your body temperature is above normal or if you have mental/mood changes, headache, or dizziness.
Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug, especially dizziness and muscle/nervous system problems such as extrapyramidal symptoms and tardive dyskinesia (see Side Effects).
During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away.
Since untreated mental/mood problems (such as schizophrenia, bipolar disorder, schizoaffective disorder) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.
Perphenazine passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: 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).
Also report the use of the following drugs, which might increase your risk of a seizure when combined with perphenazine, such as isoniazid (INH), other antipsychotic medications (e.g., haloperidol, quetiapine), lithium, tramadol, tricyclic antidepressants (e.g., amitriptyline), and alcohol, among others. Consult your doctor or pharmacist for details.
Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-seizure drugs (e.g., carbamazepine), medicine for sleep or anxiety (e.g., alprazolam, diazepam, zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., chlorpromazine, risperidone, amitriptyline, trazodone).
Check the labels on all your medicines (e.g., cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.