Olanzapine

Olanzapine is an effective atypical antipsychotic drug. From the chemical point of view, olanzapine is a thienobenzodiazepine.

Olanzapine - Chemical Structure

Most likely, this drug is best known by its trade name Zyprexa®.

Indications

For what it uses

The use of olanzapine is indicated for the treatment of the following diseases:

Schizophrenia;
Manic episodes, moderate to severe.

Warnings

Due to the serious side effects that may occur, the use of olanzapine in elderly patients with dementia should be avoided.

For preventive purposes, patients on olanzapine over 65 years of age should have regular blood pressure checks.

Since olanzapine may cause an increase in body weight, patients must be constantly monitored.

Olanzapine can raise blood glucose, triglyceride and cholesterol levels, so regular blood tests must be performed to assess these factors, both before and during treatment.

Since olanzapine can promote the formation of blood clots, caution should be exercised when administering the drug in patients with a family history of coagulation disorders.

Attention should be paid to the administration of olanzapine in patients who suffer - or have suffered - from the following diseases:

Stroke or transient ischemic attack;
Parkinson's disease;
Prostate disorders;
Paralytic ileus;
Liver and / or renal disorders;
Blood disorders;
Cardiac disorders;
Diabetes;
Convulsive disorders or epilepsy.

Olanzapine treatment should not be performed in children and adolescents under the age of 18.

It is not recommended to start therapy with olanzapine - administered intramuscularly - in patients over 75 years of age.

Olanzapine can cause drowsiness, therefore - if this effect appears - driving vehicles and using machines is not recommended.

If treatment with olanzapine is stopped abruptly, so-called withdrawal symptoms may occur. Such symptoms are sweating, insomnia, tremor, anxiety, nausea and vomiting. Therefore, therapy should not be stopped abruptly, but gradually.

Interactions

Olanzapine-induced drowsiness may increase when the drug is administered concomitantly with antidepressants, anxiolytics or tranquilizers .

It may be necessary to change the dose of olanzapine administered if the drug is taken concomitantly with:

Anti-Parkinson drugs ;
Carbamazepine, a drug used to treat epilepsy;
Fluvoxamine, an antidepressant drug;
Ciprofloxacin, an antibiotic.

The combination of olanzapine and alcohol should be avoided.

Side effects

Olanzapine can induce various side effects. The type of adverse effects and the intensity with which they occur varies from person to person, depending on the sensitivity that each patient has towards the drug.

The following are the main side effects that may occur during olanzapine therapy.

Nervous system disorders

Olanzapine therapy can cause various disorders of the central nervous system, including:

Sedation;
Drowsiness;
dizziness;
Restlessness;
Irritability;
Aggressive behaviors;
Anxiety;
Tremor;
Dyskinesia;
Unusual movements, especially of the face and tongue;
Difficulty speaking;
Extreme tiredness;
Confusional state;
Loss of memory or forgetfulness;
Convulsions, often in patients with previous seizure disorders;
Epileptic seizures, in patients with epilepsy.

Reproductive system and breast disorders

Treatment with olanzapine can cause sexual dysfunction, decreased libido and galactorrhoea (abnormal milk secretion) in both sexes.

In women, moreover, the drug can cause breast enlargement, hypomenorrhea (ie reduction of the menstrual cycle) or amenorrhea (absence of the menstrual cycle).

In men, however, olanzapine can cause erectile dysfunction, priapism (that is, a long and painful erection not accompanied by sexual arousal) and gynecomastia (ie an abnormal development of the breasts).

Muscle disorders

Olanzapine can cause various disorders of the muscles that can manifest themselves in the form of unmotivated pain, loss of strength, stiffness or muscle spasms.

Cardiovascular disorders

Treatment with olanzapine can promote the formation of blood clots and can cause orthostatic hypotension (ie a sharp drop in blood pressure when you move from an extended position or sitting to an upright position), fainting, slow heart rate and rhythm abnormalities heart.

Furthermore, there have been cases of sudden and unexplained death.

Diabetes

Diabetes may occur following olanzapine treatment - or worsening of this in already ill patients - sometimes associated with ketoacidosis or coma.

Furthermore, olanzapine can cause an increase in blood sugar and urine levels.

Endocrine disorders

Olanzapine therapy can cause hyperprolactinaemia, which can cause an increase in blood levels of the hormone prolactin.

Hepatobiliary disorders

Treatment with olanzapine may cause liver disorders and jaundice.

Allergic reactions

Olanzapine - like all drugs - can trigger allergic reactions in sensitive individuals. These reactions can occur in the form of a skin rash, itching or swelling of the mouth and throat.

Urinary tract disorders

Treatment with olanzapine may cause urinary incontinence or inability to urinate.

Gastrointestinal disorders

Olanzapine therapy may cause pancreatitis (inflammation of the pancreas) accompanied by severe stomach pain, feeling sick and fever.

Other side effects

Other side effects that may occur following olanzapine therapy are:

Temperature;
Accelerated breathing;
Increased sweating;
Increased appetite;
Increased body weight;
Increased cholesterol and lipids in the bloodstream;
Increased blood levels of uric acid, creatine phosphokinase and liver enzymes;
Dry mouth sensation;
Skin eruptions;
Photosensitivity reactions;
Fluid retention causing swelling of hands, feet and ankles;
arthralgia;
Epistaxis (blood in the nose);
Abdominal distension;
Hair loss;
Worsening of the symptoms of Parkinson's disease in patients with this condition.

Elderly patients with dementia

Elderly patients with dementia are more susceptible to the following side effects:

Stroke;
Pneumonia;
Extreme tiredness;
Urinary incontinence;
Walking problems;
Falls;
Temperature;
Visual hallucinations;
Redness of the skin.

Furthermore, cases of death have also been reported.

Overdose

In the event of overdose with olanzapine it is necessary to immediately contact a doctor and go to the nearest hospital.

The symptoms that can occur after taking an overdose of medication are:

Increased heart rate;
Impaired heart rhythm;
Agitation or aggression;
Difficulty of the word;
Reduced level of consciousness;
Convulsions;
Temperature;
Drowsiness;
Slow down of breathing;
Hypotension or hypertension;
Coma.

Action mechanism

Olanzapine is a potent antagonist of D2 dopamine receptors (DA) and 5-HT2A receptors of serotonin (5-HT). In fact, these two endogenous monoamines play an important role in the development of psychiatric diseases.

Mode of Use - Posology

Olanzapine is available for oral administration in the form of coated tablets or orodispersible tablets (ie which dissolve in the mouth).

Coated tablets should be swallowed whole and without chewing and can be taken either on an empty stomach or on a full stomach.

Orodispersible tablets, on the other hand, must be dissolved in the mouth, or they can be dissolved in a full glass of water or in drinks such as orange juice, apple juice, milk or coffee. Drinks may change color or become dull after the tablet is dissolved, it is necessary to mix well and drink immediately.

It is advisable to take olanzapine tablets at the same time each day.

Olanzapine is also available for intramuscular administration. It appears as a powder that must be dissolved in a special solvent - by the doctor or nurse - just before administration.

In this case, since the drug is administered by specialized personnel - unlike what can happen with oral administration - it is very unlikely that an overdose will occur.

The dosage of olanzapine must be established by the doctor on an individual basis, depending on the type and severity of the disease to be treated.

Below are some indications on the doses of medication usually administered.

Oral administration

The dose of olanzapine usually administered is 5-20 mg, to be taken once a day.

Intramuscular administration

Olanzapine is administered into the muscle tissue of the buttock. The doses usually used are 150-300 mg every two weeks, or 300-405 mg every four weeks.

Pregnancy and breastfeeding

Before using olanzapine during pregnancy (known or presumed) it is absolutely necessary to seek medical advice. In fact, newborns whose mothers took olanzapine during the last trimester of gestation developed adverse effects, such as tremors, weakness, muscle stiffness, sleepiness, agitation, respiratory disorders and feeding difficulties.

Because olanzapine is excreted in breast milk, breastfeeding mothers should not be treated with the drug.