The word NSAID is expanded as Non Steroidal Anti-inflammatory Drugs. The same group of drugs are also called Non-Narcotic Analgesics or Analgesic-Antipyretic-Anti-inflammatory Drugs.
The word used is – Non-steroidal – because steroids are one of the most potent anti-inflammatory drugs; and we want to emphasize that NSAIDs exert anti-inflammatory effect, but they are not steroidal in nature.
Why the word Non-Narcotic Analgesics –
The most potent analgesic drugs are Narcotics (Narcosis = Central nervous system depression) (Morphine-like drugs).
NSAIDs produce analgesic effect without depressing central nervous system; hence they are termed Non-Narcotic Analgesics.
Its extremely important not to have narcotic / central nervous system depressant effect for for relieving minor pains in day to day life. Thus Non-Narcotics are the most commonly used drugs for relieving pain.
Mention the differences between Narcotic Analgesics and Non-narcotic Analgesics.
|Narcotic Analgesics||Non-Narcotic Analgescis|
|Produce CNS depression||Less CNS depression|
|Analgesic action is mainly central||Analgesic action is mainly peripheral|
|Opioid receptors||Peripheral pain receptors|
|Cardiovascular system depression||Minimal|
|Abuse liability is remarkable (Drug dependence)||No abuse liability|
|Physical dependence||No physical dependence|
|Mostly used for emergencies and severe pains||Mostly used for day to day pain relief and mild to moderate pains|
|e.g. Morphine, Buprenorphine, Pethidine, Pentazocin, Fentanyl||e.g. Aspirin, Paracetamol, Ibuprofen, Diclofenac,Naproxen, Mefenamic acid|
|Type of pain relieved|
|Severe||Mild to moderate|
|Visceral pain||Integumental; sometime also visceral|
|Deeper pain||Superficial pain|
Mention the non-narcotic analgesics without anti-inflammatory action.
Paracetamol (Acetaminophen) and Ketorolac have analgesic action, but they are poor (modest) at anti-inflammatory action.
This is why paracetamol is mostly used for relieving pain (analgesic action) and decreasing body temperature (anti-pyretic action), but not for inflammatory conditions.
Similarly ketorolac is mostly used to relieve the pain.
Mention pharmacological actions of Aspirin / NSAIDs / Non-narcotic analgesics.
- Analgesic action: This is mostly peripheral, by acting on peripheral pain receptors by decreasing their sensitivity. Because NSAIDs inhibit cyclooxygenase-2 (COX-2) and inhibit synthesis of prostaglandins (PGs), Bradykinin (BK) TNF-alpha (Tumor necrosis factor alpha).
- Antipyretic action: By 2 mechanisms. 1- Central, by acting on hypothalamus and re-setting the thermostat. 2-Peripheral, by producing cutaneous vasodilation (dilation of blood vessels in the skin) and sweating –> dissipation of heat
- Anti-inflammatory action: on – chemical mediators, stabilizes lysosomal memb, decrease mucopolysaccharides, decrease edema (1.2-1.5 g q 8h)
- Antiplatelet action: (anti-aggregatory action on platelets) (only ASPIRIN IN LOW DOSES)): Inhibits TXA2 synthesis [(Thromboxane A2)– Irreversible COX inhibition – (acetylation) – Long lasting effect – 7-10 days – (lifetime of platelets) (platelets – no nucleus – no de novo protein synthesis)]
- Respiration & Acid base imbalance: Moderate doses: Resp alkalosis. Toxic doses: accumulation of co2 , resp acidosis and metabolic acidosi
- Decrease renal/stomach PGs