Anticoagulants like heparin reduce blood-clot formation and ensure free blood flow through major organs in the body. Thrombolytic drugs dissolve blood clots, which can block blood vessels and deprive the heart or brain of blood and oxygen, possibly leading to heart attack or stroke. For instance, antiepileptic drugs reduce the activity of overexcited brain areas and reduce or eliminate seizures. Antipsychotic drugs are used to regulate certain brain chemicals called neurotransmitters , which do not function properly in people with psychoses, major mental disorders often characterized by extreme behaviors and hallucinations , such as in schizophrenia . Antipsychotic drugs can often significantly alleviate hallucinations and other abnormal behaviors.
Antidepressant drugs reduce mental depression .
Antimanic drugs reduce excessive mood swings in people with manic-depressive illness, which is characterized by behavioral fluctuations between highs of extreme excitement and activity and lows of lethargy and depression. Both types of drugs act by normalize chemical activity in the emotional centers of the brain. Antianxiety drugs, also referred to as tranquilizers , treat anxiety by decreasing the activity in the anxiety centers of the brain. Sedative-hypnotic drugs are used both as sedatives to reduce anxiety and as hypnotics to induce sleep. Analgesic drugs reduce pain and are generally categorized as narcotics and non-narcotics.