Medications: Nervous, Respiratory, Circulatory & Digestive Systems

Medications by System

Nervous System Medications

Adrenaline (SNA): Used in cases of asthma, allergies, and premature births (fenoterol). Also used in Parkinson's disease (dopamine) and inhibition of milk secretion (bromocriptine). Dopamine increases blood pressure.

• Parasympathetic Cholinergic Drugs: Produce parasympathetic stimuli.
• Acetylcholine: Causes vasodilation in the heart.
• Indirect Cholinergics: Prevent acetylcholine from being metabolized (e.g., Physostigmine, Neostigmine). Used in glaucoma, crosses the blood-brain barrier (BBB), and can be lethal in high doses.
• Anticholinergics: Block the effects of acetylcholine (e.g., Atropine, Scopolamine).

Respiratory System Medications

Most commonly used drugs include oxygen and cough modifiers. They are used in bronchial asthma (bronchodilators).

• Centrally Acting Antitussives:
  • Narcotics: Codeine.
  • Non-narcotics: Nascopina, Oxolamine.
• Peripherally Acting Antitussives: (e.g., Perebron).
• Expectorants: Increase mucus production (e.g., Ambroxol).
• Mucolytics: Liquefy bronchial secretions (e.g., Bromohexine).
• Bronchodilators: Relax smooth muscle of the bronchial tree. They are classified as:
  • Adrenergic Agonists: Cause relaxation of smooth muscle (e.g., Salbutamol).
  • Anticholinergics: Override the effects produced by acetylcholine (e.g., Theophylline, Aminophylline).
  • Other bronchodilators: Berodual.

Circulatory System Medications

• Cardiotonics: Increase myocardial contractility.
  • Cardiac Glycosides: Some have cardiotonic and antiarrhythmic effects (e.g., Digoxin, which increases the force of heart muscle contraction).
• Antiarrhythmics: Used to treat arrhythmias (e.g., Lidocaine, Propranolol, Atenolol, Amiodarone).
• Calcium Channel Blockers: Reduce calcium entry into cardiac cells (e.g., Diltiazem, Verapamil, Nifedipine).
• Antihypertensives: Used to treat high blood pressure. These are classified as:
  • Diuretics: Hydrochlorothiazide, Furosemide, Mannitol, Spironolactone.
  • Direct Vasodilators: Hydralazine (reduces peripheral resistance).
  • Calcium Channel Blockers.
  • Angiotensin-Converting Enzyme (ACE) Inhibitors: Cause vasodilation.
  • Adrenergic Inhibitors: Methyldopa (reduces blood pressure).
• Antianginals: Prevent or relieve angina (e.g., Nitrites and Dinitrates, which relax smooth muscle in blood vessels, the digestive tract, and the urinary tract).

Digestive System Medications

• H2 Antihistamines: Cimetidine, Ranitidine, Famotidine (act by competitive antagonism with histamine).
• Anticholinergics: Atropine, Scopolamine (inhibit gastric secretion).
• Proton Pump Inhibitors (PPIs): Omeprazole (acts on the H+ secretion process, inhibiting the production of hydrochloric acid in the stomach).
• Antacids: React with hydrochloric acid (HCl) (e.g., Sodium Bicarbonate, Aluminum Hydroxide, Magnesium Hydroxide).
• Laxatives: Modify stool consistency.
  • Stimulants: Promote fluid accumulation in the lumen.
  • Osmotic Laxatives: Magnesium, Lactulose, Glycerin.
  • Lubricants: Liquid Paraffin.
• Antidiarrheals:
  • Absorb toxins: Activated Carbon.
  • Alter intestinal motility: Loperamide.
• Antiemetics: Used for the treatment of vomiting.
  • Butyrophenones, Phenothiazines (produce dopaminergic blockade).
  • Metoclopramide, Domperidone.
• Antispasmodics: Relieve pain caused by gastrointestinal spasms (e.g., Papaverine, Propinoxato (Viadil), Trimebutine).