Paracetamol-paracetamol used for-paracetamol side effects and paracetamol made of.

What is paracetamol?

Paracetamol or N-acetyl para aminophenol is an aromatic compound which is also known as acetaminophen. 

Paracetamol is an analgesic as well as antipyretic non narcotic drugs . It is used as a medicinal drugs to treat pain and fever.

Paracetamol structure 

Paracetamol or N-acetyl para aminophenol is an aromatic compound which is also known as acetaminophen.

Paracetamol consists of a benzene ring core which substituted by one hydroxyl group and the nitrogen atom of an amide group in the para position. 

The amide group is acetamide . It is an extensively conjugated system. Paracetamol structure is shown below.

Chemical properties of paracetamol 

Paracetamol consists of a benzene ring core which substituted by one hydroxyl group and the nitrogen atom of an amide group in the para position. The amide group is acetamide . 

It is an extensively conjugated system, as one lone pair on the‘O’-atom, the benzene pi electron cloud, the nitrogen lone pair ,the p-orbital on the carbonyl carbon and one lone pair on the carbonyl oxygen are all conjugated .

The presence of two activating groups make the benzene ring highly reactive toward aromatic electrophilic substitution . 

Since the substituents are ortho, para orienting and para with respect to each other , so all positions on the ring are more activated .

The conjugation also highly reduces the basicity of the  oxygen and the nitrogen atom, while making the hydroxyl acidic through delocalization of charge developed on the phenoxide anion.

What is paracetamol made of ?

There are two several method for preparation of paracetamol . ( I  ) Preparation of paracetamol from nitro benzene . ( II) Preparation of paracetamol from phenol.

Paracetamol from nitro benzene

On reduction of nitro benzene in neutral solution in presence of Zn, NH4Cland 50% alcoholic solution, nitrobenzene convert into phenyl hydroxyl amine . 

This phenyl hydroxyl amine under goes rearrangement reaction in presence of dilute HCl change into p-amino phenol.

The acetylation of this into p-amino phenol in presence of acetic anhydride produced paracetamol or N-acetyl para aminophenol.

Paracetamol from phenol

The nitration of phenol with sodium nitrate and dilute sulfuric acid gives mixture of two isomers . 
From this mixture the wanted 4-nitro phenol can easily be separated by steam distillation . 

The nitro group is then reduced to an amine by sodium borohydride ,giving 4-amino phenol.

Finally, the acetylation of 4-amino phenol in presence of acetic anhydride gives the expected product, paracetamol.

What is paracetamol used for?

Paracetamol  is known as acetaminophen ,is a medication used to treat pain and fever. It is typically used for mild to moderate pain relief .  

Paracetamol is also used for severe pain, such as cancer pain and pain after surgery. Paracetamol is generally safe at recommended doses . 

The recommended maximum daily dose for an adult is 3-4  gm. Paracetamol  is used for reducing fever in people of all ages. 

But paracetamol may be used to treat fever in children only if their temperature is higher than 38.5ᵒC or recommended by physicians.

 Paracetamol is used for mild to moderate pain relief .Based on a systematic review many physicians recommended paracetamol as a first-line treatment for lower back pain .

The USA college of Rheumatology recommends paracetamol as one of several treatment options for people with arthritis pain of the hip, hand or knee that does not improve with exercise . 

Paracetamol has only a small benefit in osteoarthritis . It  can relieve pain mild arthritis.

Paracetamol has relatively little anti-inflammatory activity. Many experiment proved that the use of paracetamol in combination with caffeine as one of several frist-line therapies for treatment of tension and migraine headaches.

Paracetamol combined with NSAIDs may be more effective for treating postoperative pain as well as for dental pain than either paracetamol or NSAIDs alone. 

Paracetamol Side effects 

Acute over doses of paracetamol can cause potentially fatal liver damage. 

Acetaminophen can cause serious liver damage and the possibility of a moderately increased risk of upper gastrointestinal complications such as stomach bleeding, if more directed is used.

Long termed use of paracetamol can causes the different skin diseases .

An association exists between paracetamol use and asthma . 

Certain evidence suggests that this association likely reflects confounders rather than being truly causal.

Paracetamol over dose side effects 

In general , the recommended maximum daily dose of paracetamol for healthy adults is 3-4 gm. Higher doses may lead to toxicity.

Untreated paracetamol over dose results in a lengthy, painful illness . Signs and symptoms of paracetamol toxicity may initially be absent or non specific symptoms. 

The first symptoms of over dose usually begin several hours after ingestion , with nausea, vomiting , sweating, and pain as acute liver failure starts.

People who take over doses of paracetamol do not fall asleep of lose consciousness . Untreated over dose paracetamol can lead to liver failure and death within days.

Some studies have found an association between paracetamol and a slight increase in kidney cancer.

paracetamol vs aspirin 

In contrast to aspirin , paracetanol does not prevent blood clotting . Thus it may be used in people who have concerns with blood coagulation . In addition to it does not cause gastric irritation .

Again, paracetamol does not help reduce inflammation but aspirin does. Unlike aspirin paracetamol is generally considered safe for children . 

Because it is not associated with a risk of Reye’s  syndrome in children with viral illnesses. If taken recreationally withopioids, weak evidence suggests that it may cause hearing loss.

Summary

• What is paracetamol ?
• What is paracetamol made of ?
• What is paracetamol used for ?
• paracetamol Side effects .
• paracetamol over dose side effects.
• paracetamol vs aspirin.  

Friedel crafts alkylation reaction . Click here