Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Fluanxol Depot (Flupentixol). If you are concerned about side effects, discuss the risks and benefits of Fluanxol Depot (Flupentixol) with your doctor.

The following side effects have been reported by at least 1% of people taking Fluanxol Depot (Flupentixol). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• changes in menstrual periods
• Constipation
• decreased interest in sexual activity
• decreased sexual ability
• dizziness
• Dry Mouth
• fatigue
• increased production of saliva
• increased sensitivity of the skin to sunlight
• increased sweating
• swelling of breasts (in men and women)
• unusual secretion of milk
• weight changes

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blurred vision or other eye problems
• circular eye movement
• decreased blood pressure (fainting, dizziness, lightheadedness)
• difficult urination
• fast, pounding, or irregular heartbeat
• mask-like face
• muscle spasms, especially of the neck and back
• new or worsening constipation
• severe restlessness or need to keep moving
• shuffling walk
• signs of liver damage (e.g., yellowing of skin or whites of eyes, abdominal pain, loss of appetite, dark urine, light-coloured stools, tiredness, or weakness)
• skin rash
• stiffness of arms and legs
• symptoms of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worse when breathing in, coughing, coughing up blood, sweating, or passing out)
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• trembling and shaking of fingers and hands
• uncontrolled body movements (e.g., twisting movements, chewing movements, puffing cheeks, lip smacking or puckering)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• long-lasting (more than 4 hours) and painful erection
• seizures
• signs of a Heart Attack (e.g., chest pain or pressure, pain extending through shoulder and arm, nausea and vomiting, sweating)
• signs of neuroleptic malignant syndrome (e.g., high Fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, or fainting)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a Stroke (e.g., headache, loss of coordination, slurred speech, weakness, numbness, or unexplained pain in the arm or leg)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Fluanxol Depot (Flupentixol).

2% Solution
Each mL contains flupenthixol decanoate 20 mg. Nonmedicinal ingredients: medium-chain triglycerides. Supplied as 2 mL ampoules, packages of 5, or as 10 mL vials.

10% Solution
Each mL contains flupenthixol decanoate 100 mg. Nonmedicinal ingredients: medium-chain triglycerides. Supplied as 2 mL vials.

Do not use Fluanxol Depot (Flupentixol) if you:

• are allergic to flupenthixol or any ingredients of Fluanxol Depot (Flupentixol)
• are allergic to other thioxanthines (e.g., thiothixine)
• are intoxicated with alcohol or other medications (such as hypnotics, other opioids like Codeine or Morphine, or psychotropic medications for mental health conditions)
• have brain damage
• have liver damage
• have serious heart disease, brain disease, or Kidney Disease

There may be an interaction between flupenthixol and any of the following:

• aclidinium
• alcohol
• Alfuzosin
• amantadine
• Amiodarone
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• Anagrelide
• antihistamines (e.g., cetirizine, doxylamine, Diphenhydramine, Hydroxyzine, Loratadine)
• anti-Parkinson's medications (e.g., amantadine, Apomorphine, Bromocriptine, levodopa, Pramipexole, Ropinirole)
• antipsychotics (e.g., chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• antiseizure medications (e.g., Clobazam, Ethosuximide, Gabapentin, Levetiracetam, Phenobarbital, Phenytoin, primidone, Topiramate, Valproic acid, zonisamide)
• atropine
• azelastine
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• barbiturates (e.g., butalbital, pentobarbital, phenobarbital)
• belladonna
• benzodiazepines (e.g., Alprazolam, Diazepam, Lorazepam)
• Benztropine
• brimonidine
• bromocriptine
• Buprenorphine
• Buspirone
• cannabis
• chloral hydrate
• chloroquine
• cisapride
• Dextromethorphan
• Disopyramide
• Domperidone
• Donepezil
• Dronedarone
• efavirenz
• Epinephrine
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• Famotidine
• Fingolimod
• Flavoxate
• Flecainide
• formoterol
• Galantamine
• Glucagon
• glycopyrrolate
• hydroxychloroquine
• Indapamide
• ipratropium
• kava kava
• ketotifen
• lithium
• Loperamide
• lopinavir
• macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
• mefloquine
• Methadone
• Methylphenidate
• Metoclopramide
• mifepristone
• Mirtazapine
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Rasagiline, Selegiline, Tranylcypromine)
• muscle relaxants (e.g., Baclofen, Cyclobenzaprine, methocarbamol, orphenadrine)
• Nabilone
• narcotic pain relievers (e.g., codeine, Fentanyl, morphine, Oxycodone)
• Nitroglycerin
• Octreotide
• Olopatadine
• Oxybutynin
• pentamidine
• Perampanel
• pimozide
• potassium chloride (potassium supplements)
• procainamide
• Propafenone
• Romidepsin
• quinidine
• quinine
• quinolone antibiotics (e.g., levofloxacin, Norfloxacin, moxifloxacin)
• ritonavir
• Rivastigmine
• romidepsin
• St. John's wort
• salmeterol
• saquinavir
• scopolamine
• selective serotonin reuptake inhibitors (SSRIs; e.g., Paroxetine, Fluoxetine, Citalopram)
• serotonin antagonists (anti-emetic medications; e.g., Granisetron, Ondansetron)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., Desvenlafaxine, Duloxetine, Venlafaxine)
• Solifenacin
• sotalol
• sulfamethoxazole
• tacrolimus
• Tamoxifen
• Tapentadol
• Tetrabenazine
• thalidomide
• thiazide diuretics (water pills; e.g., Hydrochlorothiazide, indapamide, Metolazone)
• tiotropium
• Tolterodine
• Tramadol
• Trazodone
• Trimethoprim
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• "triptan" migraine medications (e.g., Eletriptan, Sumatriptan)
• Tryptophan
• tyrosine kinase inhibitors (e.g., Bosutinib, Dasatinib, imatinib, Nilotinib, Sunitinib)
• umeclidinium
• Vardenafil
• vilanterol
• Zolpidem
• Zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Fluanxol Depot (Flupentixol). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Fluanxol Depot (Flupentixol).

Abnormal heart rhythms: Fluanxol Depot (Flupentixol) can cause abnormal heart rhythms. Certain medications (e.g., Sotalol, quinidine, thioridazine, Chlorpromazine, Pimozide,  moxifloxacin, Mefloquine, pentamidine, arsenic trioxide, Tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should not be used in combination with flupenthixol. You are more at risk for this type of abnormal heart rhythm and its complications if you:

• are female
• are older than 65 years of age
• have a family history of sudden cardiac death
• have a history of heart disease or abnormal heart rhythms
• have a slow heart rate
• have congenital prolongation of the QT interval
• have Diabetes
• have had a stroke
• have low potassium, magnesium, or calcium levels
• have nutritional deficiencies

Blood counts: Fluanxol Depot (Flupentixol) can decrease the number of neutrophils (a type of white blood cell that helps fight infection), red blood cells (which carry oxygen), and platelets (which help your blood to clot). Your doctor will do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.

Blood sugar: Flupenthixol may cause an increase in blood sugar levels (may cause a loss of blood glucose control) and glucose tolerance may change. This may happen to people who have never had high blood glucose levels. People with diabetes may find it necessary to monitor their blood sugar more frequently while using Fluanxol Depot (Flupentixol).

If you have diabetes or are at risk for developing diabetes, discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.

Dementia: Adults with dementia appear to be at a greater risk of sudden death when they are taking flupenthixol. This appears to happen more often in seniors with dementia. If you have dementia, discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.

Drowsiness/reduced alertness: Fluanxol Depot (Flupentixol) may cause drowsiness. Do not drive, operate machinery, or perform other potentially hazardous tasks until you have determined how Fluanxol Depot (Flupentixol) affects you.

Glaucoma: Fluanxol Depot (Flupentixol) may make glaucoma worse. If you have glaucoma, discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Fluanxol Depot (Flupentixol) to build up in the body, causing side effects. If you have liver disease or decreased liver function, discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.

Flupenthixol may also cause decreased liver function or make liver problems worse. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Movement disorders: The use of flupenthixol has been associated with a potentially irreversible movement disorder called tardive dyskinesia (TD). This syndrome involves the involuntary movements of facial muscles and the tongue. The risk of a person developing this syndrome is usually but not always linked to treatment duration and the total amount of antipsychotic medications taken.

If you develop signs and symptoms of TD during treatment with flupenthixol, including sticking the tongue out, smacking the lips, pursing or puckering of lips, and blinking eyes rapidly, contact your doctor as soon as possible.

Neuroleptic malignant syndrome (NMS): Flupenthixol, like other antipsychotic medications, can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever; muscle stiffness; confusion or loss of consciousness; sweating, racing, or irregular heartbeat; or fainting, get immediate medical attention.

Parkinson's Disease: Fluanxol Depot (Flupentixol) may make symptoms of Parkinson's disease worse. If you have Parkinson's disease, discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.

Prolonged erection (priapism): If an erection lasts longer than 4 hours (a rare occurrence), seek immediate medical assistance. If this condition is not treated quickly, tissue damage and permanent loss of the ability to have an erection could result.

Seizures: Flupenthixol may make pre-existing seizure disorders worse. If you have a seizure disorder, discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.

Stopping the medication: If Fluanxol Depot (Flupentixol) needs to be stopped, it should be done gradually, under the supervision of your doctor. If you suddenly stop taking Fluanxol Depot (Flupentixol), you may experience symptoms of withdrawal.

Take the medication exactly as prescribed by your doctor, and do not stop taking the medication without checking with your doctor first.

Pregnancy: Fluanxol Depot (Flupentixol) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Fluanxol Depot (Flupentixol), contact your doctor immediately. Newborn babies who have been exposed to Fluanxol Depot (Flupentixol) in the last 3 months of pregnancy have experienced withdrawal symptoms after birth.

Breast-feeding: Fluanxol Depot (Flupentixol) passes into breast milk. If you are a breast-feeding mother and are taking flupenthixol, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Fluanxol Depot (Flupentixol) have not been established for children.

Seniors: Seniors are at an increased risk of experiencing severe side effects of flupenthixol due to decreased kidney, liver, and heart function. Discuss with your doctor how Fluanxol Depot (Flupentixol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fluanxol Depot (Flupentixol), and whether any special monitoring is needed.