Antipsychotics also known as neuroleptics or major tranquilizers, are a class of medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia and bipolar disorder. Antipsychotics are usually effective in relieving symptoms of psychosis in the short term. They are increasingly being used in the management of non-psychotic disorders. 

Today, two generations of antipsychotics are distinguished. First-generation antipsychotics are also known as typical antipsychotics were discovered in the 1950s and used to treat psychosis. Typical antipsychotics are not particularly selective and also block dopamine (D2) receptors. Blocking D2 receptors in these other pathways is thought to produce some unwanted side effects that the typical antipsychotics can produce. They were commonly classified on a spectrum of low potency to high potency, where potency referred to the ability of the drug to bind to dopamine receptors, and not to the effectiveness of the drug. 

Second-generation drugs are known as atypical antipsychotics have been developed more recently. Atypical antipsychotic drugs have a similar blocking effect on D2 receptors, however, most also act on serotonin receptors (Pic. 1). Second-generation drugs are hypothesized as having a more beneficial influence on the negative symptoms than the older (typical) antipsychotics.


The range of side effects patients commonly encounter includes:

  • weight gain
  • endocrine disturbances (related to any of the organs of the body that make hormones)
  • sedation
  • anticholinergic effects (agents that block neurotransmitter called acetylcholine)
  • hypotension (low blood pressure)
  • seizures

Less common and unpredictable reactions are an abnormal condition or disease of the blood (blood dyscrasias), cardiotoxicity (causing cardiac problems), sudden death, and the neuroleptic malignant syndrome (life-threatening reaction that occasionally occurs to antipsychotics).

Associated diseases

  • hyperprolactinemia (high prolactin level)
  • metabolic syndrome (a group of risk factors that is associated with the risk of developing cardiovascular disease and type 2 diabetes)


Antipsychotic medication blocks type 2 dopamine (D2) receptors which results in increased prolactin secretion (hyperprolactinaemia). This complication is most associated with conventional antipsychotics, amisulpride, and risperidone, which can raise prolactin levels 10-fold above pretreatment values in both men and women, but because women start off at higher levels, they are more likely to experience symptoms.

The long-term use of antipsychotics is associated with side effects such as involuntary movement disorders, gynecomastia, and metabolic syndrome. They are also associated with increased mortality in elderly people with dementia.

Risk factors

The contraindications for antipsychotics include:

  • central nervous system depressants (sedatives and tranquilizers that slow brain activity)
  • cigarette smoking
  • antidepressants
  • beta-blockers (cardiac medication)


Preventing side effects of antipsychotics medication

The prevention of antipsychotics side effects should be prescribing antipsychotic medications only when indicated for a clearly diagnosed illness where alternative strategies including psychological interventions have been unsuccessful. Treatment of an episode of primary affective illness with a brief period of psychotic symptoms is an important example. It’s almost always important to start at a lower dose and slowly titrate the dose upwards whilst carefully monitoring tolerability due to side effects.

Antipsychotics affect fertility through changes in prolactin level as the typical antipsychotics are regarded as the most common medications related to hyperprolactinaemia. They lead to acute and persistent increase of prolactin levels and thus affecting hormonal balance. 

Female fertility

The great response of prolactin in women of a reproductive age, who are not nursing or pregnant, leads to the inhibition of the normal pulsatile secretion of gonadotropin-releasing hormone (GnRH) of the hypothalamus. These, not so frequent, pulses of GnRH result in regular menses, on the one hand, but impaired follicular growth on the other. Greater impairment of pulsatile GnRH secretion leads to an anovulatory stage with menses being too frequent, too heavy, or infrequent (amenorrhea). If the release of the egg is compromised, sperm can not be encountered and fertilization does not occur.

Further restraining of pulsatile GnRH secretion provokes deficient secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), in amounts not adequate to induce a proper ovarian response (the ability to recruit adequate follicles). That provokes a hypoestrogenized amenorrheic cycle and side reactions of estrogen deficiency - comparable to what occurs during menopause or infertility. Hence, as hyperprolactinaemia is associated with estrogen suppression, the initial prolactin elevation is clinically identified by reproductively related symptoms, primarily in females.

Male fertility

Even in men, antipsychotic medication can lead to infertity. No sperm could be present in the ejaculate (azoospermia). Likewise, men could suffer from difficulty maintaining an erection and decreased sexual desire.

All patients treated with these prolactin-elevating agents should be questioned regarding their menstrual cycle patterns, and prolactin levels should be monitored on a regular basis. Should disruption of menstrual cycles occur, the dose may be reduced, if clinically feasible. 

The increase in prolactin that occurs through the use of conventional antipsychotics develops over the first week of treatment and remains elevated throughout the period of use. Once treatment stops, prolactin levels return to normal within 2-3 weeks.

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