SIDE EFFECTS: See also Warning section. Drowsiness, dizziness, lightheadedness, dry mouth, blurred vision, constipation, and trouble sleeping may occur. If any of these effects persist or worsen, tell 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. 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: stiff muscles, severe muscle spasms/cramping (such as twisting neck, arching back, eyes rolling up), restlessness/constant need to move, shaking (tremor), slow/shuffling walk, drooling/trouble swallowing, mask-like expression of the face. 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 taking this medication do not have serious side effects. Tell your doctor right away if any of these unlikely but serious side effects occur: fainting, confusion, depression/suicidal thoughts, 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, thiothixene 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, signs of infection (such as fever, persistent sore throat), severe stomach/abdominal pain, seizures. 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. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: See also Warning section. Before taking this medication, tell your doctor or pharmacist if you are allergic to it; 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. Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood problems (such as low red/white/platelet blood cell counts), a certain eye condition (glaucoma), heart problems (such as fast/irregular heartbeat, low blood pressure), liver disease, breast cancer, brain disorder/tumor/injury, drug/alcohol/substance abuse, Parkinson's disease, seizures, a certain severe reaction to other antipsychotic-type medications (neuroleptic malignant syndrome-NMS), slow movement of the gut/intestines (such as chronic constipation, intestinal blockage), difficulty urinating (such as due to prostate problems). This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana. This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness. Before having surgery or imaging procedures (such as certain X-rays, CT scans) requiring the use of contrast dye (such as metrizamide), tell your doctor or dentist that you are using this medication and about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). This medication may make you sweat less, making you more likely to get heat stroke. Avoid doing things that may cause you to overheat, such as hard work or exercise in hot weather, or using hot tubs. When the weather is hot, drink a lot of fluids and dress lightly. If you overheat, quickly look for a place to cool down and rest. Get medical help right away if you have a fever that does not go away, mental/mood changes, headache, or dizziness. Older adults may be more sensitive to the side effects of this drug, especially dizziness, lightheadedness, drowsiness, confusion, constipation, trouble urinating, extrapyramidal symptoms (EPS), and tardive dyskinesia (TD) (see Side Effects). Dizziness, lightheadedness, drowsiness, and confusion can increase the risk of falling. 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 rarely 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) 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. It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: 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 include: anticholinergic/antispasmodic drugs (such as atropine, dicyclomine, scopolamine), lithium, drugs that increase the amount of dopamine in your body (such as cabergoline, levodopa, pergolide, ropinirole), drugs that lower blood pressure (such as guanethidine, alpha blockers like prazosin). Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine). 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.

OVERDOSE: 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: severe drowsiness/dizziness, inability to wake up (coma).