How do moderate and high doses of cocaine affect the human body?

Hint: Cocaine belongs to a class of stimulants. It interferes with the transport of neurotransmitter dopamine. Cocaine has stimulating action on the central nervous system. Cannabinoids are also being abused by some sports people these days.

Complete answer:
Cocaine also is known as coca alkaloid is obtained from the Erythroxylum coca. Commonly it is called coke or crack usually taken by snorting Cocaine interferes with the transport of neurotransmitter dopamine.
Action of dopamine- During normal communication, dopamine is released from neurons at the synapse (a small gap between two neurons) and binds to special proteins called dopamine receptors on neighbouring neurons. In this process, dopamine acts as a chemical messenger that sends signals from neurons to neurons. Another special protein called a transporter removes dopamine from synapses and recycles them for later use.
Effect of cocaine in the transmission of neurotransmitter dopamine -cocaine be clearance of dopamine at synapses by binding to the dopamine transporter. The dopamine then builds up at the synapse, producing an amplified signal in the receiving neuron. This is the cause of the euphoria that often occurs immediately after taking the medicine.
Effect of Moderate doses of cocaine
1.Feeling of euphoria and increased energy
2. Increased respiration rate Increased blood pressure and increased heart rate (after initial retention)
3. Increased productivity for simple tasks
4. Dilated pupils
5.Feeling of well being and increased confidence
Effect of high doses of cocaine
1.Irritability
2.Anxiety
3.Panic attacks
4.Paranoia
5. A psychopathy in which a person loses touch with reality and experiences auditory hallucinations.
6. Many chronic cocaine users lose their appetite and experience significant weight loss and malnutrition. Cocaine has a strong toxic effect on the heart and cardiovascular system.
Parkinson’s disease can also occur after many years of cocaine use.

Note:
Some methods of using cocaine can have their own side effects. Regular snorting of cocaine can cause loss of smell, nosebleeds, difficulty swallowing, hoarseness, and complete irritation of the nasal septum, leading to chronic inflammation and a runny nose.
Smoking cocaine can damage the lungs and worsen asthma.
People who inject cocaine are more likely to have a puncture site called a forearm mark and are at risk of infectious diseases such as HIV and hepatitis C.