NEET MDS Lessons
Pharmacology
Oxycodone
About equal potency to morphine. Very effective orally.
It is combined with aspirin or acetaminophen for the treatment of moderate pain and is available orally
Oxycodone is a semisynthetic compound derived from thebaine, with agonist activity primarily at mu receptors.
Neurolept Anesthesia
An antipsychotic agent such as droperidol plus an opiate analgesic agent such as fentanyl or sufentanil. This latter agent is approximately eight to ten times more potent than fentanyl.
Quinolone
Quinolones and fluoroquinolones form a group of broad-spectrum antibiotics. They are derived from nalidixic acid.
Fluoroquinolone antibiotics are highly potent and considered relatively safe.
MOA : Quinolones act by inhibiting the bacterial DNA gyrase enzyme. This way they inhibit nucleic acid synthesis and act bacteriocidically.
Drugs :Nalidixic acid, Ciprofloxacin , Levofloxacin, Norfloxacin ,Ofloxacin, Moxifloxacin , Trovafloxacin
PHARMACOLOGY OF VASOCONSTRICTORS
All local anesthetics currently used in dentistry today produce some degree of vasodilatation. This
characteristic results in the increased vascularity of the injected site and results in a shorter duration of local
anesthetic action due enhanced uptake of the local anesthetic into the bloodstream.
- Using a “chemical tourniquet” to prolong the effect of local anesthetics
- The vasoconstrictive action of epinephrine reduces uptake of local anesthetic resulting in a significant increase in the duration of local anesthetic action.
- the addition of vasoconstrictors in local anesthetic solutions will:
1. Prolong the effect of the local anesthetic
2. Increase the depth of anesthesia
3. Reduces the plasma concentration of the local anesthetic
4. Reduces the incidence of systemic toxicity
5. Reduces bleeding at surgical site
Local anesthetics containing epinephrine produce:
1. Localized
VASOCONSTRICTION MEDIATED BY ALPHA RECEPTOR ACTIVATION
i. Hemostasis at surgical site
ii. Ischemia of localized tissue
2. Systemic
HEART
i. Increased heart rate (β1)
ii. Increased force and rate of contraction (β 1)
iii. Increased cardiac output
iv. Increases oxygen demand
v. Dilation of coronary arteries
vi. Decreases threshold for arrhythmias
LUNGS
i. Bronchodilation (β2 )
SKELETAL MUSCLE
i. Predominately vasodilation (fight or flight response) (β 2 )
CNS
i. Minimal direct effect due to difficulty in crossing the blood-brain barrier. Most effects on the CNS are manifestations of the vasoconstrictor on other organs such as the heart.
Concentrations of vasoconstrictors
1. Epinephrine The most commonly used epinephrine dilution in dentistry today is 1:100000. However it appears that a 1:200000 concentration is comparable in effect to the 1:100000 concentration.
2. Levonordefrin Levonordefrin is a synthetic compound very similar in structure to epinephrine. It is the only alternate choice of vasoconstrictor to epinephrine. It is prepared as a 1:20000 (0.05mg/ml)(50 mcg/ml) concentration with 2 % mepivacaine.
Cardiovascular considerations
The plasma concentration of epinephrine in a patient at rest is 39 pg/ml.1 The injection of 1 cartridge of lidocaine 1:100000 epinephrine intraorally results in a doubling of the plasma concentration of epinephrine.
The administration of 15 mcg of epinephrine increased heart rate an average of 25 beats/min with some individuals experiencing an increase of 70 beats/min.
Clinical considerations
It is well documented that reduced amounts of epinephrine should be administered to patients with:
HEART DISEASE (ANGINA HISTORYOF MI)
POORLY CONTROLLED HIGH BLOOD PRESSURE
It is generally accepted that the dose of epinephrine should be limited to 0.04 mg (40 mcg) for patients that have these medical diagnoses
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
Immunosuppressive antibodies can be classified mainly into monoclonal and polyclonal antibodies, targeting specific components of the immune system.
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Monoclonal Antibodies:
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Basiliximab: Targets the IL-2 receptor on T cells, inhibiting T-cell activation. It is FDA approved for use in renal transplantation to prevent acute rejection.
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Alemtuzumab: Targets CD52, a protein found on the surface of mature lymphocytes. It is used for treating chronic lymphocytic leukemia and as an induction agent in kidney transplantation.
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Rituximab: Targets CD20 on B cells, leading to B-cell depletion. It is used in various conditions, including non-Hodgkin lymphoma and rheumatoid arthritis.
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Daclizumab: Targets the IL-2 receptor (CD25) and is used in renal transplantation to prevent acute rejection.
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Eculizumab: Targets complement component C5, inhibiting the complement cascade. It is used in conditions like paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome.
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Polyclonal Antibodies:
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Rabbit Antithymocyte Globulin (rATG): A polyclonal antibody that targets multiple T-cell surface markers, leading to T-cell depletion. It is used as an induction agent in kidney transplantation and for treating acute rejection.
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Equine Antithymocyte Globulin (eATG): Similar to rATG, it targets T cells and is used in transplantation settings.
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Mechanisms of Action:
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Depletion of Immune Cells: Many antibodies work by depleting specific immune cell populations (e.g., T cells or B cells) to reduce the immune response against transplanted organs or in autoimmune diseases.
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Blocking Activation Signals: Some antibodies block key receptors involved in T-cell activation, preventing the immune response from being initiated.
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Inhibition of Complement Activation: Antibodies like eculizumab inhibit the complement system, which can contribute to tissue damage in antibody-mediated rejection.
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Clinical Applications:
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Organ Transplantation: Antibodies are commonly used to prevent rejection in kidney, liver, and heart transplants.
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Autoimmune Diseases: They are also used in treating conditions like rheumatoid arthritis, lupus, and multiple sclerosis.
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Potential Side Effects:
- Infections: Due to immune suppression, patients are at increased risk of infections.
- Allergic Reactions: Some patients may experience allergic reactions to antibody therapies.
- Infusion Reactions: These can occur during the administration of monoclonal antibodies, leading to symptoms like fever, chills, and hypotension.
Heroin (diacetyl morphine)
Heroin is synthetically derived from the natural opioid alkaloid morphine
Largely owing to its very rapid onset of action and very short half-life, heroin is a popular drug of abuse
It is most effective when used intravenously
Heroin is rapidly deacetylated to 6-monoacetyl morphine and morphine, both of which are active at the mu opioid receptor
More lipid soluble than morphine and about 2½ times more potent. It enters the CNS more readily.