paracitamol used for
Reading File
Finding Sources
Searching the Web
paracetamol uses indications mechanism of action
Reading File
Finding Sources
Reading File
Reading File
Here is a comprehensive overview of Paracetamol (Acetaminophen) — also sold as Tylenol, Panadol, Calpol, and others.
What is Paracetamol Used For?
1. Pain Relief (Analgesia)
Paracetamol is a first-line analgesic for mild to moderate pain, including:
- Headache and migraine
- Toothache
- Muscle aches (myalgia)
- Back pain
- Postoperative / postpartum pain
- Arthritis (joint pain — though it does NOT treat the underlying inflammation)
- General body aches
It is comparable in analgesic potency to aspirin, and its effects are additive when combined with NSAIDs (e.g., ibuprofen).
2. Fever Reduction (Antipyresis)
Paracetamol is a standard antipyretic used to reduce fever in:
- Infections (flu, cold, COVID-19, etc.)
- Post-vaccination fever
- Children and adults alike
3. Preferred Agent in Specific Groups
Paracetamol is the drug of choice when other pain relievers are unsuitable:
| Situation | Why Paracetamol is Preferred |
|---|---|
| Children | Safe and well-tolerated |
| Aspirin allergy | No cross-reactivity (usually) |
| Peptic ulcer history | Does not irritate the stomach |
| Hemophilia / bleeding risk | Does not affect platelets |
| Pregnancy | Generally considered safe |
| Patients on anticoagulants (careful) | Does not increase bleeding risk like NSAIDs |
| Bronchospasm triggered by aspirin | Generally safe |
How Does It Work?
The exact mechanism is not fully understood, but paracetamol:
- Weakly inhibits COX-1 and COX-2 enzymes in the brain (centrally), reducing prostaglandin synthesis — this explains both its analgesic and antipyretic effects
- Does NOT significantly inhibit COX in peripheral tissues — which is why it has no meaningful anti-inflammatory effect (unlike NSAIDs)
- Also interacts with endogenous opioid, cannabinoid, and serotonergic systems in the CNS
- A key metabolite (AM404) activates cannabinoid CB1 receptors and TRPV1 channels in the brain, contributing to pain relief
Dosage
- Adults: 500–1000 mg every 4–6 hours; maximum 4 g (4000 mg) per day
- Children: Weight-based dosing (typically 10–15 mg/kg every 4–6 hours)
- Available as: tablets, capsules, liquid suspension, suppositories, and IV (Ofirmev)
Important Safety Points
| Risk | Details |
|---|---|
| Hepatotoxicity (liver damage) | The main danger. Overdose (>10 g in adults) produces toxic metabolite NAPQI, which destroys liver cells. Antidote: N-acetylcysteine (NAC) |
| Alcohol use | Chronic drinkers have lower glutathione reserves — even therapeutic doses can cause liver damage |
| Liver disease | Use with caution or reduce dose |
| Renal disease | Chronic use can worsen kidney function |
| Drug interactions | Anticonvulsants (phenytoin, carbamazepine) increase toxic metabolite production; high doses can raise INR in warfarin users |
What Paracetamol Does NOT Do
- It is not anti-inflammatory — it won't reduce swelling or treat conditions like rheumatoid arthritis effectively
- It does not inhibit platelet aggregation (unlike aspirin)
- It does not affect uric acid levels (safe in gout)
Sources: Katzung's Basic and Clinical Pharmacology 16th Ed.; Rosen's Emergency Medicine — Lippincott Illustrated Reviews: Pharmacology
This is a shared conversation. Sign in to Orris to start your own chat.