This is a list of adverse effects of the antipsychotic
olanzapine, sorted by frequency of occurrence.[1]
Very common
Very common adverse effects of olanzapine, occurring more than 10%, include:
Weight gain (dose-dependent). Weight gain of over 7% of a person's initial body weight prior to treatment is in this category of very common too with some estimates of its incidence putting it at around 40.6%. This adverse effect is most likely the result of its potent
5-HT2C receptor and
H1 receptor blockade (or more specifically
inverse agonism).[2]
Hyperprolactinemia elevated blood levels of the hormone,
prolactin. Prolactin is one of the hormones that plays a key role in lactation. Long-term uncontrolled hyperprolactinaemia can lead to bone demineralisation (osteoporosis) and an increased risk of fractures (breaks). It tends to produce hyperolactinaemia less often than
risperidone,
paliperidone and the
typical antipsychotics but more often than
quetiapine and
clozapine.
Hyperglycaemia (elevated blood glucose levels). This may be the result of olanzapine's inhibitory effects on the
M3 receptor which regulates the release of insulin from the pancreas.[2]
Extrapyramidal symptoms (EPS) (dose-dependent). Tends to produce less extrapyramidal side effects than typical antipsychotics but more extrapyramidal side effects than sertindole, clozapine and quetiapine.[9][10]
Mild and transient constipation and
xerostomia (dry mouth)
Dizziness
Weight gain of over 15% of one's initial body weight. Is reported to occur in approximately 7.1% of patients.
Glucosuria (glucose in the urine. This is a consequence of hyperglycaemia)
Transient, asymptomatic
elevations of hepatic aminotransferases (ALT, AST), especially in early treatment. ALT and AST are liver enzymes which are often tested for as a measure of liver function.
Increased total
bilirubin (a by product of the breakdown of haem — a part of blood cells that is used to carry oxygen. In most people this is an indication of impaired liver function)
Pancreatitis, swelling of the pancreas which supplies the body with insulin.
Neuroleptic malignant syndrome a potentially fatal complication of antipsychotic drug treatment. Presents with hyperthermia, tremor, tachycardia (high heart rate), mental status change (e.g. confusion), etc.
Jaundice, which is basically when the body's ability to clear a by product (called
bilirubin) of the breakdown of an essential component of the blood called
haem, is impaired leading to yellow discolouration of the skin, eyes and mucous membranes.
Diabetic coma
Diabetic ketoacidosis. Type II diabetes mellitus is basically where the body cannot effectively utilise sugars to produce energy due to the fact that its cells have become unresponsive to the hormone, insulin, which allows cells to utilise sugars for energy. This in turn forces the body to burn fats for energy and fats require conversion to ketone bodies in order to be utilised by the cells of the body as an energy source. The ketone bodies are acidic hence when the body is entirely reliant on these ketone bodies for energy the levels in the blood reaches a point where it overwhelms the body's natural mechanisms to keep blood pH (a measure of acidity) within a safe range, leading to the blood becoming acidic which is potentially damaging to the tissues of the body due to the ability of acidic environments to
denature the proteins of the body.
^Lexi-Comp Inc. (2010) Lexi-Comp Drug Information Handbook 19th North American Ed. Hudson, OH: Lexi-Comp Inc.
ISBN978-1-59195-278-7.
^
abBrunton, L; Chabner, B; Knollman, B (2010). Goodman and Gilman's The Pharmacological Basis of Therapeutics (12th ed.). New York: McGraw-Hill Professional.
ISBN978-0-07-162442-8.
^Leucht, S; Cipriani, A; Spineli, L; Mavridis, D; Örey, D; Richter, F; et al. (Sep 2013). "Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia: a multiple-treatments meta-analysis". The Lancet. 382 (9896): 951–62.
doi:
10.1016/S0140-6736(13)60733-3.
PMID23810019.
S2CID32085212.
^Moncrieff, J.; Leo, J. (September 2010). "A systematic review of the effects of antipsychotic drugs on brain volume". Psychological Medicine. 40 (9): 1409–1422.
doi:
10.1017/S0033291709992297.
PMID20085668.
S2CID23522488.