Side Efleects of Antipsychotic Drugs:

The most common side effects are symptoms of central nervous system i.e. Extrapyramidal  Symptoms (EPS)  including such as: 

Parkinsonism, which occurs in 40 percent of  presenting EPS. Patient present difficulty in mastication movement, weakness and muscle fatigue. 

Akathisia,  occur in 50 percent of all patient presenting EPS. Patient has strong urge to move about and has difficulty in sitting still. It occurs within two weeks of  treatment. Dystonia occurs less than EPS. Patient develops contraction of muscles of the tongue, eye. jaw,  and neck (producing  torticollis) and extraoccular muscles. 

Tardive Dyskinesia, is  less  frequent side effect of  EPS.  It occurs in 3  per  cent of patient due to sudden withdrawal of drugs after giving for long time. The other side effect ill EPS is Neuroleptic Malignant Syndrome (NMS),  This is very rare but can be futal. The treatment for extra pyramidal symptoms are use of antiparkinsonian drugs. Antiparlunsonian drugs includc the anticholinergic and antihistamine drugs. Anticholinergic drugs block  the secretion so they reduce the symptoms of akathisia and acute dystonia, whereas antihistamines have effect  like anticholinergic drugs but ir  is also effective to prevent tardive dpskinesia.