DRUG-TYPES-2

Types of Drugs

Antiarrhythmics

  • Arrhythmia: Variation in heartbeat, irregular heart rate.

  • Key Components of Heart's Electrical System:

    • Sinoatrial (SA) Node: Heart's natural pacemaker.

    • Atrioventricular (AV) Node: Connects atria and ventricles.

    • Bundle of His: Carries electrical signals to ventricles.

    • Purkinje Fibers: Transmit signals to ventricles for contraction.

Cardiac Electrical Impulse Process

  1. SA Node generates impulse.

  2. Impulse spreads through atria, causing contraction.

  3. Travels to AV Node; signal delayed.

  4. Moves through Bundle of His to ventricles.

  5. Ventricles contract, pumping blood.

ECG Waveforms

  • P wave: Atrial depolarization.

  • QRS complex: Ventricular depolarization.

  • T wave: Ventricular repolarization.

Common Arrhythmias

  • Atrial Flutter: Upper chambers beat too fast.

  • Premature Atrial Contraction (PAC): Extra heartbeat from upper chambers.

  • Premature Ventricular Contractions (PVCs): Extra heartbeat from lower chambers.

  • Ventricular Fibrillation: Rapid, uncoordinated contractions.

Antiarrythmia Drug Classes

  1. Membrane-Stabilizing Agents (Class I)

    • Slow sodium ion movement in cells.

    • Example: Disopyramide, Flecainide, Lidocaine.

  2. Disopyramide

    • ventricular arrythmias

    • anticholinergic

    • for patients with heart failure

    • SIDE EFFECTS: dry mouth, constipation, urinary retention, blurred vision

  3. Flecainide

    • ventricular arrythmias

    • SIDE EFFECTS: dizziness, blurred vision, tremor, nausea, and vomiting

  4. Lidocaine

    • local anesthetic

  5. Potassium Channel Blockers

    • Block potassium flow, delaying repolarization.

    • Example: Amiodarone, Dofetilide.

  6. Other Medications

    • Digoxin: Slows ventricular rate in atrial fibrillation.

    • Atropine: Treats bradycardia.

Antibiotics

Types of Bacteria

  • Aerobic: Requires oxygen to survive.

  • Anaerobic: Cannot live in oxygen presence.

Antibiotic Classes

  1. Sulfonamides

    • Block folic acid synthesis.

    • Common Use: UTIs.

    • Side Effects: Rashes, nausea.

    • Examples: Sulfamethoxazole-trimethoprim.

  2. Penicillins

    • Prevent cell wall formation.

    • Common Uses: Various infections including STDs.

    • Side Effects: Diarrhea.

    • Examples: Amoxicillin, Ampicillin.

  3. Cephalosporins

    • Similar action to penicillins.

    • Used in various surgical prophylaxis.

    • Multiple generations available.

  4. Macrolides

    • Treat pulmonary infections.

    • Example: Azithromycin.

    • Side Effects: Gastrointestinal distress.

  5. Quinolones

    • Disrupt bacterial DNA coiling.

    • Side Effects: Nausea, joint issues.

    • Examples: Ciprofloxacin, Levofloxacin.

  6. Aminoglycosides

    • Inhibit protein synthesis in bacteria.

    • Side Effects: Nephrotoxicity, ototoxicity.

    • Example: Gentamicin.

Other Key Antibiotics

  • Vancomycin: Treats MRSA.

  • Clindamycin: For serious gram-positive infections.

  • Metronidazole: Effective against anaerobic bacteria and protozoa.

  • Pentamidine: For Pneumocystis Carinii.

  • Linezolid: Used for MRSA and VRE.

Anticoagulant Drugs

  • Heparin: Prevents clot formation, does not dissolve existing clots.

  • Warfarin: Prevents future clots.

  • Dabigatran, Rivaroxaban: Direct thrombin inhibitors, do not require monitoring.

Antidotes

  • Heparin: Protamine sulfate.

  • Warfarin: Vitamin K (Phytonadione).