Elderly Patients
Elderly patients suffering from a mental disorder associated learning abnormality (dementia-related
psychosis) are at an increased risk when using Quetiapine. These patients may experience an increased incidence of blood vessel-related brain diseases, heart failure or lung infection (
pneumonia) which can be possibly fatal. Quetiapine should not be used in such patients. Take necessary precautions while using Quetiapine in patients with a risk factor for
stroke.
Suicidal Thoughts and Behavior
Children and young adults (age 18 to 24 years) or patients with mood disorder,
schizophrenia, and depression/psychotics disorders are at an increased risk when using Quetiapine. These patients may experience worsening of the
depression and suicide-related/unusual changes in behaviors such as agitation,
anxiety, panic attacks, irritability, etc. Patients should be monitored closely for suicide-related/unusual changes in behaviors in the starting of therapy or during dose adjustment. Discontinuation of Quetiapine, the lowest effective dose or changes in the therapy should be considered in such patients.
Neuroleptic Malignant Syndrome
Patients taking Quetiapine are at an increased risk. Drug-induced life-threatening reaction (neuroleptic
malignant syndrome) may occur in these patients and may experience symptoms such as high
fever, abnormal mental status, muscle rigidity, irregular blood pressure, abnormal heart rhythm, increased heart rate, sweating, increased
creatinine phosphokinase, kidney failure, and myoglobin in the urine. Monitoring and treatment of neuroleptic malignant syndrome, discontinuation of Quetiapine or other drugs not required for the combined therapy should be considered. Antipsychotic drug therapy should be reintroduced after recovery from the neuroleptic malignant syndrome.
High Blood Sugar
Patients with high blood sugar are at an increased risk while taking Quetiapine. These patients may experience an increased level of glucose and acids in the blood, weight gain, a complication of high blood sugar (diabetic hyperosmolar
coma) or fatality. These patients should be observed for symptoms of high blood sugar such as weakness, increased thirst or urine passage and excessive eating (
polyphagia). Such patients should be monitored regularly for body weight changes or worsening of sugar level. Fasting blood sugar test should be performed in the starting and during the treatment with Quetiapine.
Metabolic Changes
Children or patients taking Quetiapine are at an increased risk. These patients may experience metabolic changes such as an increase in weight, changes in
lipids levels such as an increase in
triglycerides, total
cholesterol, high-density lipoprotein, and a decrease in high-density lipoprotein. Patients should be monitored for metabolic changes, and appropriate treatment should be used.
Tardive Dyskinesia
Elderly patients especially elderly women taking Quetiapine, are at an increased risk. These patients may experience irreversible and involuntary body movements (tardive
dyskinesia). This risk increases as the treatment duration increases. Long-term antipsychotic treatment should be given in patients with serious illness. The smallest dose for the shortest duration should be used in such patients. Quetiapine should be discontinued, or dose reduction should be considered in patients developing symptoms of involuntary body movements.
Low Blood Pressure on Quickly Standing
Elderly patients or patients taking Quetiapine are at an increased risk. Quetiapine may cause
dizziness, increased heart rate, loss of consciousness,
falls, or low blood pressure on quickly standing up in these patients in the starting period of Quetiapine therapy. Precaution should be taken in patients with low blood volume, low body fluid, taking antihypertensive drugs, and in blood vessel related heart and brain diseases. Starting dose should be kept small, and dose should be increased slowly afterward. If low blood pressure still develops, then the previous dose should be considered.
Low Levels of Blood Cells
Patients with history or already low levels of white blood cells count/absolute neutrophil count, or taking Quetiapine are at an increased risk. Quetiapine may decrease the number of leukocytes (leukopenia), granulocytes, or neutrophils in these patients. Complete blood count test should be performed in such patients in the initial period and during drug therapy. Patients should be informed to report the doctor immediately on the occurrence of any signs of infection and low levels of granulocytes. On the occurrence of low white blood cell or neutrophil count, Quetiapine should be discontinued. Patients should be monitored and treated for symptoms of infection such as
fever.
Cloudiness of the Lens in the Eye
Adults and children using Quetiapine for long-term are at an increased risk. Long-term use of Quetiapine may cause cloudiness of the lens in the eye (
cataracts) in these patients. An appropriate method such as slit lamp exam should be used for the diagnosis of the cataract in the starting and during Quetiapine therapy.
Abnormal Heart Rhythm
Elderly patients, patients taking medicines known to cause electrolyte imbalance/QT prolongation, an overdose of Quetiapine or with any other illness are at an increased risk. These patients may experience prolonged heartbeat (QT prolongation). Quetiapine should not be used in patients with a history of abnormal heartbeat, low levels of potassium/magnesium, birth defects related to abnormal heart rhythm, or taking drugs known to cause QT prolongation such as quinidine, gatifloxacin, or methadone. Precaution should be used in patients with heart failure, thickened heart muscles (heart hypertrophy) or taking neuroleptics.
Seizures
Elderly patients, patients with a history of
seizures, condition associated with seizures, or taking Quetiapine are at an increased risk. Quetiapine may cause seizures in these patients. Precaution should be taken in such patients.
Increased Levels of Prolactin
Patients taking Quetiapine are at an increased risk. These patients may experience increased levels of prolactin, which may lead to reduced pituitary gonadotrophin secretion and ultimately reduced functioning of the reproductive system. These patients may also experience abnormal milky discharge from breasts (
galactorrhea), the absence of
menstruation (
amenorrhea), enlarged breasts in men (
gynecomastia), and erection abnormality (
impotence). Decreased bone density may occur in these patients.
Increased Levels of Liver Enzymes
Patients taking Quetiapine are at an increased risk. These patients may experience increased levels of transaminases such as alanine aminotransferase.
Memory and Movement Problems
Patients taking Quetiapine are at an increased risk. Quetiapine may cause drowsiness, sedation,
falls, and abnormality in thinking, judgment or movements. Patients should take necessary precaution while
operating heavy machines such as automobiles.
Prolonged Erection of the Penis
Patients taking Quetiapine are at an increased risk. These patients may experience prolonged erection of the penis (
priapism). Surgical procedures should be considered for the treatment of priapism.