NEET MDS Lessons
Pharmacology
TCI -Target Controlled Infusion
TCI is an infusion system which allows the anaesthetist to select the target blood concentration required for a particular effect and then to control depth of anaesthesia by adjusting the requested target concentration
Mechanism
Instead of setting ml/h or a dose rate (mg/kg/h), the pump can be programmed to target a required blood concentration.
• Effect site concentration targeting is now included for certain pharmacokinetic models.
• The pump will automatically calculate how much is needed as induction and maintenance to maintain that concentration.
Mefenamic acid
Analgesic, anti‐inflammatory properties less effective than aspirin
Short half‐lives, should not be used for longer than one week and never in pregnancy and in children.
Enhances oral anticoagulants
Used to treat pain, including menstrual pain. It decreases inflammation (swelling) and uterine contractions.
ANTIBIOTICS
Chemotherapy: Drugs which inhibit or kill the infecting organism and have no/minimum effect on the recipient.
Antibiotic these are substances produced by microorganisms which suppress the growth of or kill other micro-organisms at very low concentrations.
Anti-microbial Agents: synthetic as well as naturally obtained drugs that attenuate micro-organism.
SYNTHETIC ORGANIC ANTIMICROBIAL DRUGS
Sulfonamides
Trimethoprim-sulfamethoxazole
Quinolones – Ciprofloxacin
ANTIBIOTICS THAT ACT ON THE BACTERIAL CELL WALL
Penicillins
Cephalosporins
Vancomycin
INHIBITORS OF BACTERIAL PROTEIN SYNTHESIS
Aminoglycosides - Gentamicin
Antitubercular Drugs: Isoniazid & Rifampin
Tetracyclines
Chloramphenicol
Macrolides – Erythromycin, Azithromycin
Clindamycin
Mupirocin
Linezolid
ANTIFUNGAL DRUGS
Polyene Antibiotics (Amphotericin B, Nystatin and Candicidin)
Imidazole and Triazole Antifungal Drugs
Flucytosine
Griseofulvin
ANTIPROTOZOAL DRUGS
Antimalarial Drugs – Quinine, Chloroquine, Primaquine
Other Antiprotozoal Drugs – Metronidazole, Diloxanide, Iodoquinol
ANTIHELMINTHIC DRUGS
Praziquantel
Mebendazole
Ivermectin
ANTIVIRAL DRUGS
Acyclovir
Ribavirin
Dideoxynucleosides
Protease inhibitors
Characteristics of Opioid Receptors
mu1
Agonists : morphine phenylpiperidines
Actions: analgesia bradycardia sedation
mu2
Agonists : morphine phenylpiperidines
Actions: respiratory depression euphoria physical dependence
delta
Actions: analgesia-weak, respiratory depression
kappa
Agonists: ketocyclazocine dynorphin nalbuphine butorphanol
Actions: analgesia-weak respiratory depression sedation
Sigma
Agonists: pentazocine
Action: dysphoria -delerium hallucinations tachycardia hypertension
epsilon:
Agonists: endorphin
Actions: stress response acupuncture
Patient positioning
The most common medical emergency encountered in the dental office setting is syncope. So patients in the supine or semi-supine position to improve venous return and cerebral blood flow provided that the position is tolerated by the patient and is appropriate for their medical condition.
Thrombolytic Agents:
Tissue Plasminogen Activator (t-PA, Activase)
t-PA is a serine protease. It is a poor plasminogen activator in the absence of fibrin. t-PA binds to fibrin and activates bound plasminogen several hundred-fold more rapidly than it activates plasminogen in the circulation.
Streptokinase (Streptase)
Streptokinase is a protein produced by β-hemolytic streptococci. It has no intrinsic enzymatic activity, but forms a stable noncovalent 1:1 complex with plasminogen. This produces a conformational change that exposes the active site on plasminogen that cleaves a peptide bond on free plasminogen molecules to form free plasmin.
Urokinase (Abbokinase)
Urokinase is isolated from cultured human cells.Like streptokinase, it lacks fibrin specificity and therefore readily induces a systemic lytic state. Like t-PA, Urokinase is very expensive.
Contraindications to Thrombolytic Therapy:
• Surgery within 10 days, including organ biopsy, puncture of noncompressible vessels, serious trauma, cardiopulmonary resuscitation.
• Serious gastrointestinal bleeding within 3 months.
• History of hypertension (diastolic pressure >110 mm Hg).
• Active bleeding or hemorrhagic disorder.
• Previous cerebrovascular accident or active intracranial bleeding.
Aminocaproic acid:
Aminocaproic acid prevents the binding or plasminogen and plasmin to fibrin. It is a potent inhibitor for fibrinolysis and can reverse states that are associated with excessive fibrinolysis.
Factors affecting onset and duration of action of local anesthetics
pH of tissue
pKa of drug
Time of diffusion from needle tip to nerve
Time of diffusion away from nerve
Nerve morphology
Concentration of drug
Lipid solubility of drug