NEET MDS Lessons
Pharmacology
Midazolam -Intravenous Anesthetics
Midazolam is a benzodiazepine used for preoperative sedation, induction of anesthesia, or maintenance of anesthesia in short procedures.
Needle selection
Nerve blocks:
Inferior alveolar- 25 G short (LLU technique)
PSA- 25 G short
Mental/Incisive- 25 G short
Palatal- 27/30 G short/ultrashort
Gow-Gates/Akinosi- 25 G long
Infraorbital- 25 G long
Field Block:
ASA 25/27 short
Infiltration:
Infiltration/SP 25/27 short
PDL/Intraosseous
PDL 27/30 short
Intraosseous 30 short/ultrashort
COAGULANTS
An agent that produces coagulation (Coagulation is a complex process by which blood forms clots).
ANTICOAGULANTS
An anticoagulant is a substance that prevents coagulation; that is, it stops blood from clotting.
Anticoagulants:
Calcium Chelators (sodium citrate, EDTA)
Heparin
Dalteparin Sodium (Fragmin) -Low molecular-weight heparin
Enoxaparin - Low molecular-weight heparin
Tinzaparin Sodium - Low molecular-weight heparin
Warfarin
Lepirudin - recombinant form of the natural anticoagulant hirudin: potent and specific Thrombin inhibitor
Bivalirudin - analog of hirudin: potent and specific Thrombin inhibitor
Procoagulants:
Desmopressin acetate
Antiplatelet Drugs:
Acetylsalicylic Acid, Ticlopidine, Sulfinpyrazone, Abciximab , Clopidogrel bisulfate
Fibrinolytic Drugs:
Tissue Plasminogen Activator (t-PA, Activase), Streptokinase (Streptase),
Anistreplase, Urokinase
Antagonists:
Protamine sulfate, Aminocaproic acid
Pharmacological agents used to treat blood coagulation disorders fall in to three major categories:
1. Anticoagulants: Substances that prevent the synthesis of a fibrin network which inhibits coagulation and the formation of arterial thrombi and thromboembolic clots.
2. Antiplatelet agents: Substances that reduce the adhesion and aggregation of platelets.
3. Fibrinolytic agents: Substances that promote the destruction of already formed blood clots or thrombi by disrupting the fibrin mesh.
Ciprofloxacin : Ciprofloxacin is bactericidal and its mode of action depends on blocking of bacterial DNA replication by binding itself to an enzyme called DNA gyrase
Ciprofloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria.
Enterobacteriaceae, Vibrio, Hemophilus influenzae, Neisseria gonorrhoeae
Neisseria menigitidis, Moraxella catarrhalis, Brucella, Campylobacter,
Mycobacterium intracellulare, Legionella sp., Pseudomonas aeruginosa,
Bacillus anthracis - that causes anthrax
Weak activity against: Streptococcus pneumoniae,
No activity against: Bacteroides, Enterococcus faecium, Ureaplasma urealyticum and others
It is contraindicated in children, pregnancy, and epilepsy.
Ciprofloxacin can cause photosensitivity reactions and can elevate plasma
theophylline levels to toxic values. It can also cause constipation and sensitivity to caffeine.
Dosage in respiratory infections is 500-1500 mg a day in 2 doses.
Antiplatelet Drugs:
Whereas the anticoagulant drugs such as Warfarin and Heparin suppress the synthesis or activity of the clotting factors and are used to control venous thromboembolic disorders, the antithrombotic drugs suppress platelet function and are used primarily for arterial thrombotic disease. Platelet plugs form the bulk of arterial thrombi.
Acetylsalicylic acid (Aspirin)
• Inhibits release of ADP by platelets and their aggregation by acetylating the enzymes (cyclooxygenases or COX) of the platelet that synthesize the precursors of Thromboxane A2 that is a labile inducer of platelet aggregation and a potent vasoconstrictor.
• Low dose (160-320 mg) may be more effective in inhibiting Thromboxane A2 than PGI2 which has the opposite effect and is synthesized by the endothelium.
• The effect of aspirin is irreversible.
Classification
I) Esters
1. Formed from an aromatic acid and an amino alcohol.
2. Examples of ester type local anesthetics:
Procaine
Chloroprocaine
Tetracaine
Cocaine
Benzocaine- topical applications only
2) Amides
1. Formed from an aromatic amine and an amino acid.
2. Examples of amide type local anesthetics:
Articaine
Mepivacaine
Bupivacaine
Prilocaine
Etidocaine
Ropivacaine
Lidocaine
Gabapentin (Neurontin): newer; for generalized tonic-clonic seizures and partial seizures (partial and complex)
Mechanism: unknown but know doesn’t mimic GABA inhibition or block Ca currents
Side effects: dizziness, ataxia, fatigue; drug well-tolerated and no significant drug interactions