Olanzapine

Olanzapine is a second generation antipsychotic used to treat bipolar disorder, schizophrenia and psychosis. Olanzapine is a second-generation antipsychotic (sometimes described as an ‘atypical antipsychotic’). It may also be described as a mood stabiliser. There is a naturally occurring chemical messenger ('neurotransmitter') in the brain called dopamine, which is mainly involved in thinking, emotions, behaviour and perception. With some illnesses, dopamine may be overactive, which upsets the normal balance of chemicals in the brain and can produce a variety of symptoms.

The main effect that olanzapine has is to block some dopamine receptors in the brain, correcting the overactivity of dopamine. Olanzapine also has effects on other neurotransmitters in the brain such as serotonin. This can have positive effects, including reducing movement disorders and symptoms of depression and anxiety.

Whenever starting a new medication there are often side effects, some of the side effects of olanzapine include:

• feeling sleepy, tired, weak or exhausted 

• weight gain

• increases in the levels of prolactin in the blood (may only be seen in blood tests)

• feeling dizzy or faint with a slow heart rate, especially when getting up from a lying or sitting position (this usually happens at the start of your treatment and will normally pass on its own – speak to your doctor if it doesn't)

• changes in the level of some blood cells, chemicals, circulating fats and, in early treatment, temporary increases in liver enzymes (seen only in blood tests)

• increased appetite

• tremor, muscle stiffness or unusual muscle movements

• dry mouth

• loss of strength or extreme tiredness

• water retention leading to swelling of the hands, ankles or feet

• joint pain

• sexual problems such as feeling less like having sex less and problems getting an erection

Olanzapine use has been linked to an increased risk of developing diabetes among some young people. Symptoms include:

• putting on weight

• needing to wee a lot

• needing to drink a lot

• feeling weak

• raised blood sugar levels

Here are only some of the most common side effects of olanzapine, please speak to your doctor if you would like more information.

 Please do not worry about these side effects. Some people will not get any side effects at all. If you think you are getting side effects from taking olanzapine, speak to your doctor or pharmacist. If you do get a side effect, please think about reporting it via the 'Yellow Card' system.

If you have taken more olanzapine than the dosage recommended by the doctor who prescribed it to you, you must get medial help immediately - even if you do not feel any different.