PHARMACOLOGY

 INTRACARDIAC ::

It is given quickly and directly in the cardiac muscle in sudden stoppage of a healthy heart (adrenaline in drowning ) it is the last resort of a physician to revive a standstill heart The method rarely does succeed 

Intramedullary ::

It is given in the medullary cavity of the bone when intravenous injection is not possible Glucose and saline solutions plasma and blood transfusion etc can be easily administered by this route especially in children This route is also rarely used Bone marrow transplantation is done by this method in case of blood cancer 

Intraspinal ::

These injections are administered in lower lumber region of the subarachnoid spaces surrounding the spinal cord (lumbar puncture) Spinal anesthetics diagnostic agents and antibiotics are sometimes injected there most of the operations below the umbilicus are performed now a days under spinal anaesthesia The drug so introduced intrathecally acts directly on the nervous system 

Intracerebral Intracisteral Intraventricular and Intraneural ::

These injections are given in certain parts of the brain in rare conditions These are surgical procedures and are rarely used 

    A drug may exert different effects if given by different routes for example magnesium sulfate (MgSO4) if given orally acts as purgative given parenterally it produces depressant effect if MgSO4 is given through enema it decreases intracranial tension Similarly ethylalcohol is antiseptic if applied on skin however it is central nervous system depressant if given orally Mercurials (e.g. Calomel ) are administered orally as purgative parenterally as diuretic and locally as antiseptic