20 Difference types Analgesic and Anti pyretics medicine There composition Where to use Dosage Od bd or tds
Reading File
Finding Sources
Finding Sources
Finding Sources
Analgesic-Antipyretic Drugs — Composition, Uses, Dosage & Frequency
Frequency key: OD = once daily, BD = twice daily, TDS = thrice daily, QID = four times daily.
| # | Drug (Composition / Class) | Main Use / Indication | Adult Dosage | Frequency |
|---|---|---|---|---|
| 1 | Paracetamol (Acetaminophen) — para-aminophenol derivative, non-opioid analgesic-antipyretic | Mild-moderate pain, fever | 500-1000 mg/dose (max 4 g/day) | TDS-QID |
| 2 | Aspirin (Acetylsalicylic acid) — salicylate NSAID | Pain, fever, inflammation; low-dose for antiplatelet | 300-650 mg (analgesic); 75-150 mg (antiplatelet) | TDS-QID (pain); OD (antiplatelet) |
| 3 | Ibuprofen — propionic acid NSAID | Pain, fever, mild inflammatory conditions | 400-600 mg | TDS |
| 4 | Diclofenac sodium — phenylacetic acid NSAID | Musculoskeletal pain, dysmenorrhea, post-op pain | 50 mg | BD-TDS |
| 5 | Naproxen — propionic acid NSAID (long acting) | Osteoarthritis (OA), rheumatoid arthritis (RA), dysmenorrhea | 250-500 mg | BD |
| 6 | Mefenamic acid — fenamate NSAID | Dysmenorrhea, mild-moderate pain | 250-500 mg | TDS |
| 7 | Ketorolac — acetic acid NSAID (potent, short-term only) | Acute moderate-severe pain (post-operative, renal colic) | 10 mg oral / 30 mg IM/IV | QID oral, TDS-QID IM (max 5 days) |
| 8 | Indomethacin — indole acetic acid NSAID | Gout, ankylosing spondylitis, RA | 25-50 mg | BD-TDS |
| 9 | Piroxicam — oxicam NSAID, long half-life | OA, RA | 20 mg | OD |
| 10 | Nimesulide — sulfonanilide, preferential COX-2 inhibitor | Fever, dysmenorrhea, musculoskeletal pain | 100 mg | BD |
| 11 | Etoricoxib — selective COX-2 inhibitor | OA, RA, acute gout, dental pain | 60-120 mg | OD |
| 12 | Celecoxib — selective COX-2 inhibitor | OA, RA (lower GI risk) | 100-200 mg | OD-BD |
| 13 | Meloxicam — oxicam, COX-2 preferential | OA, RA | 7.5-15 mg | OD |
| 14 | Aceclofenac — phenylacetic acid derivative | Musculoskeletal and joint pain | 100 mg | BD |
| 15 | Ketoprofen — propionic acid NSAID | Pain and inflammation (arthritis, sprains) | 50-100 mg | BD-TDS |
| 16 | Tramadol — synthetic opioid agonist + monoamine reuptake inhibitor | Moderate-severe pain | 50-100 mg (max 400 mg/day) | TDS-QID |
| 17 | Morphine sulfate — strong opioid | Severe pain (cancer, MI, post-op) | 5-10 mg IM/SC or 10-30 mg oral | Every 4 hours (as needed) |
| 18 | Codeine phosphate — mild opioid | Mild-moderate pain, cough suppression | 15-60 mg | TDS-QID |
| 19 | Etodolac — acetic acid NSAID | OA, RA | 400 mg | BD |
| 20 | Metamizole (Dipyrone/Analgin) — pyrazolone derivative | Fever, severe pain (renal/biliary colic) | 500 mg oral / 1 g IV | TDS-QID |
Key points on composition and mechanism
- Paracetamol acts mainly centrally (weak COX inhibition, thought to also act via the endocannabinoid and TRPA1 pathways); it has poor peripheral anti-inflammatory action, which is why it treats pain/fever but not inflammation.
- NSAIDs (aspirin, ibuprofen, diclofenac, naproxen, mefenamic acid, ketorolac, indomethacin, piroxicam, aceclofenac, ketoprofen, etodolac) inhibit cyclooxygenase (COX-1/COX-2), reducing prostaglandin synthesis — giving analgesic, antipyretic, and anti-inflammatory effects together.
- COX-2 selective agents (celecoxib, etoricoxib, meloxicam, nimesulide) spare COX-1 in the gastric mucosa, giving a lower GI ulcer risk but a higher cardiovascular risk profile - Lippincott Illustrated Reviews: Pharmacology.
- Opioids (tramadol, morphine, codeine) act on mu-opioid receptors in the CNS; they relieve severe pain but are not antipyretic and carry dependence/respiratory depression risk.
Safety notes
- Paracetamol overdose (>150 mg/kg or >10 g in an adult) causes severe hepatotoxicity via the reactive metabolite NAPQI depleting glutathione, per the P C Dikshit Textbook of Forensic Medicine and Toxicology - always respect the 4 g/day ceiling.
- NSAIDs carry GI ulceration, renal impairment, and cardiovascular risk with chronic/high-dose use; lowest effective dose for the shortest duration is recommended, especially in the elderly or those with peptic ulcer/renal disease.
- Ketorolac is restricted to short courses (under 5 days) because of high GI bleeding risk.
- Opioids need dose individualization, caution in respiratory disease, and monitoring for tolerance/dependence with prolonged use.
Disclaimer: These are standard textbook reference doses for adults with normal renal/hepatic function. Actual prescribing must account for age, weight, comorbidities, renal/hepatic status, and local drug formulary/guidelines - this is not a substitute for individualized clinical or pharmacist advice.
This is a shared conversation. Sign in to Orris to start your own chat.