Olanzapine (zyprexa®)

Olanzapine, clozapine, risperidone and quetiapine are part of a group of drugs called atypical antipsychotic. Although, they are not specifically drugs for dementia they are often useful. They are used to control behaviour, orientate speech and thoughts and help with hallucinations or delusions

The way these drugs work is extremely complicated and not well understood. They block many messengers that communicate between the neurons in the brain, such as dopamine, histamine and acetylcholine

Due to its complicated and broad spectrum of blocking they produce a great variety of side effects. Side effects tend to be more common and noticeable with higher dosage than with low, which are often more recommended. The most common side effects are:

• dizziness
• weight gain
• hypertension when patient change posture, such as standing from seating (specially during initial dose titration)
• faster beating of the heart
• in some patients extrapyramidal side effects occur (usually mild and transient). Extrapyramidal side effects are a group of side effect characteristic to antipsychotic drugs. They include restlessness (patients pace up and down, constantly shift their leg position or tap their feet); sustained muscle contraction, grimacing facial distortion, neck twisting and laboured breathing; occasionally, fixed staring, eyeballs move upwards and then sideways, remarking in that position; mouth wide open tongue protruding and the head tilting backwards; and Parkinsonism side effects like tremor, rigidity and poverty of facial expression
• occasional tardia dyskinesia on long term administration
• hormonal effects, such as secretion of milk from the breast, missed periods and loss of libido
• drowsiness
• speech difficulty
• exacerbation of parkinson’s disease
• increase of appetite
• diabetes mellitus

You will have a list of other less common side effects in the leaflet given with your medication

They should never been prescribed in glaucoma patients or in breast feeding women

If another medication is required, please don’t forget to check with the pharmacist

Reproduced with kind permission of Maria Sanchez our Consultant Pharmacist