Question

1. What is the difference between cross tolerance and cross dependence? What role do receptors in the brain play in both of these?What are the effects of cocaine on the body and mind (acute and chronic/long-term)?

Answer 1

Cross tolerance in simple refers to when a person develop tolerance to one drug after a long term use of it, will also develop tolerance to other form of drug which have same action.When the drug is taken it acts on the same receptor cells of the brain.For example antipsychotic medication may block dopamine receptor or serotonin receptor .Drugs like stimulant block the reuptake of epinephrine and dopamine in the brain.In opioid analgesics it binds to the most similar endorphin receptor.

Whereas cross dependence refers to when a particular long term medication is ceased due to its dependence ,it leads to withdrawal signs and symptoms in patient, in order to control this signs and symptoms another drug is given which in long run itself can change into a dependence drug.The receptor plays a major role by transduction and recognising the drug I the brain

The effects of cocaine are as following

Acute:

• Euphoria ,happiness,Irritability ,anger,doubts on others,craving, anxious
• anorexia
• Tachycardia
• Muscle spasm

Chronic:

GI :anorexia,weight loss,ulceration,malnourishment

CVS:Chest pain,aortic rupture, cardiomyopathy

CNS:stroke ,haemorrhage, Parkinson's disease, loss of cognitive functions