Written by : Dr. Urusa I Inamdar

Introduction:

Paracetamol and acetaminophen are two official names of the same chemical compound derived from its chemical name : N-acetyl-para-aminophenol . It is an aniline derivative and the most extensively used over-the-counter and prescription analgesic worldwide . It has analgesic and anti-pyretic properties similar to non – steroidal antiinflammatory drugs (NSAIDS) but contrary to them , it does not possess any antiinflammatory properties .

Pharmacodynamics:

It acts mainly in the CNS by inhibiting cyclo oxygenase ( COX-2 ) . It acts by preventing the oxidation of inactive COX to active COX and thereby preventing prostaglandins synthesis through an active metabolite influencing cannabinoid receptors .

Pharmacokinetics:

It is rapidly absorbed from the gastrointestinal tract . The peak plasma concentrations are reached in about 2-3 hrs after rectal administration and reaches total serum concentrations of 5-20 micro g/ml . It is primarily metabolized in the liver by conjugation to gluconide and sulfate .

Indications:

• Analgesic
• Antipyretic

Contraindications:

• Alcoholism
• Hepatic disease
• Viral hepatitis
• Hypertension

Drug interactions:

Paracetamol interacts with enzyme inducing substances , such as isoniazid , carbamazepine , phenytoin or barbiturates , as well as chronic alcohol excess which increases N-acetyl-p-benzoquinone imine production and the risk of toxicity .

Adverse reactions:

• Allegic dermatitis
• Thrombocytopenia
• Agranulocytosis
• Hepatic necrosis

Dosage and administration:

As directed by the physician

Presentation:

Each suppository contains Paracetamol 125 mg

Reference:

• CIMS – prescribers handbook
• Kulkarni R et al. Indian J Pharmacol 2007
• Cullen S et al Arch Dis Child
• Roberts E et al. Ann Rheum Dis. 2016

Written by : Dr. Urusa I Inamdar

1. Macrolides : inhibits bacterial protein synthesis by reversible binding to the 50s ribosomal subunit . Example : azithromycin, clarithromycin, erythromycin
2. Monobactams : inhibit synthesis of peptidoglycan causing osmotic lysis , resistant to beta lactamases and active against gram negative rods. Example: aztreonam
3. Nitrofurantoin : block aerobic energy production and synthesis of proteins , DNA ,RNA and cell walls . Example : nitrofurantoin
4. Oxacephalosporins : bind to penicillin – binding proteins (PBP) of bacteria , inhibit bacterial cell wall peptidoglycan synthesis and activate bacterial cell wall autolytic enzymes. Example : flomoxef , latamoxef
5. Oxazolidinones : cause faulty bacterial protein synthesis by binding to the 50s ribosomal subunit . Example : linezolid , tedizolid
6. Penicillins : inhibit synthesis of peptidoglycan causing osmotic lysis . Example : Amoxicillin, ampicillin,dicloxacillin
7. Penicillins with beta lactamase inhibitors : bind to penicillin binding proteins (PBP) of bacteria , inhibit bacterial cell wall peptidoglycan synthesis and activate bacterial cell wall autolytic enzymes. Example : Amoxicillin + clavulanic acid
8. Quinolones : inhibit topoisomerases that are essential for bacterial DNA replication and transcription, inhibit DNA gyrase . Example : Ciprofloxacin, ofloxacin
9. Sulfonamides : competitive inhibition of folic acid synthesis by acting as structural analogue of para-aminobenzoic acid (PABA) . Example : sulfabenzamide , sulfathiazole
10. Tetracyclines : bind reversibly to receptors on the 30s subunit of the bacterial ribosome inhibiting protein synthesis. Example : minocycline , doxycycline
11. Tyrocidins : alter cytoplasmic membrane causing cellular leakage . Example : bacitracin , tyrothricin

Reference:

• Essentials of medical pharmacology – K D Tripathi
• CIMS – prescribers handbook
• Dental notes

Written by : Dr. Urusa I Inamdar

1. Aminoglycosides : irreversible inhibition of protein synthesis by binding to receptors on the 30s subunit of bacterial ribosome. Example : amikacin , gentamicin , kanamycin
2. Carbacephems : inhibit synthesis of peptidoglycan causing osmotic lysis. Example : loracarbef
3. Cephalosporin : bind to penicillin – binding proteins (PBP) of bacteria , inhibit bacterial cell wall peptidoglycan synthesis and activate bacterial cell wall autolytic enzymes. Example : cefaclor , cefadroxil , cefalexin , cefazolin , cefepine
4. Cephalosporins with Beta lactamase inhibitors : bind to penicillin – binding proteins (PBP) of bacteria , inhibit bacterial cell wall synthesis. Example : cefoperazone + sulbactam , cefuroxime + clavulanic acid
5. Chloramphenicol : bind reversibly to a receptor site on the 50s subunit of bacterial ribosome . Example : chloramphenicol
6. Cyclic Lipopeptides : bind to bacterial membranes and cause a rapid depolarisation of membrane potential . Hence , inhibit the protein , DNA and RNA synthesis which result in bacterial cell death . Example : daptomycin
7. Diaminopyridines : inhibits dihydrofolic acid reductase of bacteria and blocks metabolic sequences in DNA synthesis . Example : trimethoprim
8. Glycopeptides : prevent further elongation and cross linking of bacterial peptidoglycan synthesis , active against gram positive bacteria including methicillin-resistant Staphylococci. Example : oritavancin
9. Glycylcyclines : bind reversibly to receptors on the 30s subunit of the bacterial ribosome inhibiting protein synthesis . Example : tigecycline
10. Ketolides : inhibits bacterial protein synthesis by reversible binding to the 50s ribosomal subunit. Example : telithromycin
11. Lincosamides : inhibit protein synthesis by interfering w/ initiation complexes and translocation reactions on the bacterial 50s subunit . Example : clindamycin , lincomycin
12. Macrocyclic antibiotics : inhibit bacterial protein synthesis by inhibiting RNA polymerase sigma subunit. Example : fidaxomicin

References

• Essentials of medical pharmacology – K D Tripathi
• CIMS – prescribers handbook
• Dental notes