Pharma Review PDF

**Autonomic Nervous System** **Page 3: Cholinergic Drugs** - **Definition and Function** - Cholinergic agonists or stimulants promote the action of acetylcholine - Also known as parasympathomimetic drugs, they imitate the effects of the parasympathetic nervous syste...

**Autonomic Nervous System** **Page 3: Cholinergic Drugs** - **Definition and Function** - Cholinergic agonists or stimulants promote the action of acetylcholine - Also known as parasympathomimetic drugs, they imitate the effects of the parasympathetic nervous system. - **Major Classes** - **Cholinergic Agonists**: Mimic acetylcholine\'s action. - **Anticholinesterase**: Inhibit the breakdown of acetylcholine at receptor sites. **Page 4: Pharmacokinetics, Pharmacodynamics, and Pharmacotherapeutics** - **Pharmacokinetics** - Poor CNS penetration; primarily peripheral effects. - Rapidly destroyed in the body; rarely given IM or IV. - Administered topically (eye drops), orally, or SQ injections. - **Pharmacodynamics** - Mimic acetylcholine action on neurons in target organs. - Effects include: - Salivation - Bradycardia - Vasodilation - Bronchoconstriction - Increased GI activity - Bladder muscle contraction - Pupil constriction - **Therapeutic Uses** - Treat atonic bladder conditions, GI disorders, glaucoma, and salivary gland hypofunction. **Page 5: Anticholinesterase Drugs** - **Categories** - **Reversible Anticholinesterase**: Short duration (e.g., donepezil, neostigmine). - **Irreversible Anticholinesterase**: Long-lasting effects, primarily toxic (e.g., echothiophate). **Page 6: Anticholinesterase Drugs - Pharmacokinetics and Nursing Responsibilities** - **Pharmacokinetics** - Readily absorbed from GIT, SQ, and mucous membranes. - Only physostigmine crosses the BBB. - **Pharmacodynamics** - Promote acetylcholine action; reversible lasts minutes to hours, irreversible lasts days to weeks. - **Therapeutic Uses** - Treat glaucoma, increase bladder tone, improve GI motility, diagnose myasthenia gravis, and manage Alzheimer's dementia. - **Nursing Responsibilities** - Ensure compliance, monitor for side effects, and maintain effective oral hygiene. **Page 7: Cholinergic Blocking Drugs** - **Pharmacokinetics** - Absorbed from eyes, GIT, and skin; belladonna alkaloids widely distributed. - **Pharmacodynamics** - Can have paradoxical effects based on dosage. - Used to treat spastic conditions in GI and urinary tracts. - **Therapeutic Uses** - Treat biliary colic, relax GI smooth muscle, and reduce secretions during surgery. - **Nursing Responsibilities** - Advise on common side effects and encourage hydration to prevent constipation. **Page 9: Adrenergic and Adrenergic Blocking Drugs** - **Definition** - Adrenergic drugs are also known as sympathomimetic drugs. **Page 10: Adrenergic Drugs** - **Classification** - Based on chemical structure: catecholamines and non-catecholamines. - **Direct-acting**: Act directly on SNS innervated organs. - **Indirect-acting**: Trigger norepinephrine release. - **Dual-acting**: Both direct and indirect actions. **Page 12: Catecholamines - Pharmacodynamics and Therapeutics** - **Pharmacodynamics** - Primarily direct-acting; can cause excitatory or inhibitory effects. - Norepinephrine has pure alpha activity; epinephrine stimulates both alpha and beta receptors. - **Therapeutic Uses** - Treat low blood pressure, bradycardia, and bronchial asthma. **Page 15: Adrenergic Blocking Drugs** - **Definition** - Also known as sympatholytic drugs; disrupt sympathetic nervous system function. - **Mechanism of Action** - Block impulse transmission at adrenergic neurons or receptor sites. **Page 16: Alpha-Adrenergic Blockers** - **Function** - Interrupt catecholamine actions at alpha receptors, leading to vasodilation and decreased blood pressure. - **Indications** - Used for hypertension, peripheral vascular disorders, and pheochromocytoma. **Page 18: Beta-Adrenergic Blockers** - **Definition** - Widely used adrenergic blockers that inhibit catecholamine action at beta-adrenergic - Also known as BETA BLOCKERS **GASTROINTESTINAL DRUGS** **1. Antacids** - **Definition**: A group of inorganic chemicals that neutralize stomach acid. They are often available over-the-counter (OTC) and can be used alone or with other drugs for treating peptic ulcers. - **Common drugs**: Magnesium hydroxide, aluminum hydroxide, simethicone, magaldrate (aluminum-magnesium complex), calcium carbonate, sodium bicarbonate. - **Pharmacokinetics**: - Neutralize gastric acid in the stomach. - Distributed throughout the gastrointestinal tract (GIT). - Primarily eliminated via feces. - **Pharmacodynamics**: - Reduces the total amount of acid in the GIT, which helps peptic ulcers heal. - **Uses**: - Relieves symptoms of acid indigestion, heartburn, dyspepsia, or GERD. - Often used for the symptomatic relief of peptic ulcer disease (PUD). - **Drug Interactions**: - Can interfere with the absorption of certain oral drugs if taken at the same time. - May reduce the absorption of drugs like digoxin, iron salts, isoniazid, quinolones, and tetracyclines if taken within two hours of antacids. **2. H2 Receptor Antagonists** - **Definition**: Drugs that block the action of histamine on the stomach's acid-secreting parietal cells. - **Common drugs**: Cimetidine, nizatidine, ranitidine, famotidine. - **Pharmacokinetics**: - Cimetidine, nizatidine, and ranitidine are rapidly and completely absorbed from the GIT. - Famotidine is not completely absorbed. - Food and antacids may reduce absorption. - These drugs are widely distributed, metabolized by the liver, and excreted in the urine. - **Pharmacodynamics**: - Block histamine from stimulating the parietal cells, reducing gastric acid production and promoting ulcer healing. - **Uses**: - Treatment of active duodenal or benign gastric ulcers. - Management of pathological GI hypersecretory conditions (e.g., Zollinger-Ellison syndrome). - Prevention of stress ulcers, especially in critically ill patients or those with reflux esophagitis or GI bleeding. - Relief of heartburn, acid indigestion, and sour stomach. - **Drug Interactions**: - Antacids reduce the absorption of cimetidine, nizatidine, and famotidine. - Cimetidine may increase blood levels of drugs such as oral anticoagulants, propranolol, benzodiazepines, theophylline, and phenytoin by reducing their metabolism in the liver. - It also inhibits alcohol metabolism, increasing blood alcohol levels. - **Adverse Effects**: - Common side effects include headache, dizziness, malaise, nausea, diarrhea, and muscle pain. - Cimetidine is associated with side effects such as rashes, loss of sexual desire, and impotence. - Famotidine and nizatidine cause fewer side effects, with headache being the most common, followed by constipation or diarrhea **3. Proton Pump Inhibitors (PPIs)** - **Definition**: These drugs inhibit the final step of acid production in the stomach, which helps reduce gastric irritation and allows ulcers to heal. - **Common drugs**: Rabeprazole, pantoprazole, omeprazole, lansoprazole, esomeprazole. - **Pharmacokinetics**: - Disrupt chemical binding in stomach cells to reduce acid production. - **Pharmacodynamics**: - Reduce acid production by inhibiting the hydrogen-potassium ATPase enzyme system of gastric parietal cells. - **Uses**: - Short-term treatment of active gastric ulcers, active duodenal ulcers, erosive esophagitis, and GERD. - Treatment of peptic ulcers associated with **H. pylori** infections in combination with antibiotics. - Long-term management of hypersecretory conditions (e.g., Zollinger-Ellison syndrome). - **Drug Interactions**: - Can interfere with the metabolism of diazepam, phenytoin, and warfarin, causing increased plasma concentrations of these drugs. - **Adverse Effects**: - CNS: Dizziness and headache. - GI: Abdominal pain, diarrhea, nausea, vomiting, dry mouth. - Respiratory: Cough, stuffy nose, hoarseness, epistaxis (nosebleeds) **4. Sucralfate** - **Definition**: A gastrointestinal protectant that works locally in the stomach. - **Action**: Reacts with hydrochloric acid to form a thick, paste-like substance that adheres to ulcers and gastric mucosa, protecting the ulcer from further damage by gastric acid. - **Pharmacodynamics**: - Protects the stomach lining by forming a barrier over the ulcer and inhibiting pepsin activity, preventing further protein breakdown in the stomach. - **Pharmacokinetics**: - Rapidly absorbed, metabolized by the liver, and excreted in feces. - Crosses the placenta and enters breast milk. - **Contraindications**: - Should not be given to patients with known allergies to the drug. - Not recommended for individuals with renal failure or undergoing dialysis. - **Adverse Effects**: - GI issues: Constipation, nausea, indigestion, gastric discomfort, dry mouth. - Other effects: Dizziness, sleepiness, vertigo, skin rash, back pain. - Caution with aluminum toxicity if combined with aluminum salts **5. Misoprostol** - **Definition**: A synthetic prostaglandin that inhibits gastric acid secretion and increases mucus production, protecting the stomach lining. - **Uses**: - Primarily used to prevent NSAID-induced gastric ulcers in high-risk patients. - **Pharmacokinetics**: - Rapidly absorbed, metabolized in the liver, and excreted in urine. - Crosses the placenta and enters breast milk. - **Contraindications**: - Contraindicated in pregnancy as it is an abortifacient (can cause miscarriages). - Caution in patients with hepatic or renal impairment. - **Adverse Effects**: - GI: Nausea, diarrhea, abdominal pain, flatulence, dyspepsia. - Genitourinary: Miscarriages, excessive bleeding, spotting, menstrual disorders **6. Laxatives** - **Types**: - **Chemical Stimulants**: Stimulate nerve plexus in the intestine wall, increasing motility (e.g., bisacodyl, senna). - **Bulk Stimulants**: Increase bulk in fecal matter, helping to stimulate peristalsis (e.g., magnesium sulfate, psyllium). - **Lubricants**: Help ease stool passage by coating the intestinal contents without affecting motility (e.g., docusate, mineral oil). - **Uses**: Treat constipation, evacuate the bowels before surgery, relieve abdominal distension. - **Adverse Effects**: - GI: Diarrhea, cramping, nausea. - CNS: Dizziness, headache, weakness. - Others: Palpitations, sweating, and fainting **7. Gastrointestinal Stimulants** - **Definition**: Drugs that stimulate GI motility by increasing parasympathetic activity or making GI tissues more sensitive to it. - **Common drugs**: Metoclopramide (Reglan), dexpanthenol. - **Pharmacodynamics**: - Metoclopramide works by blocking dopamine receptors, making GI tissues more sensitive to acetylcholine, which increases motility. - Dexpanthenol increases acetylcholine levels, stimulating parasympathetic activity. - **Uses**: - Treat delayed gastric emptying, stimulate rapid movement of GI contents. - **Adverse Effects**: - Nausea, vomiting, diarrhea, fatigue, dizziness, intestinal spasms, and cramping **8. Antidiarrheals** - **Definition**: Drugs used to treat diarrhea by slowing intestinal motility. - **Common drugs**: Bismuth subsalicylate, loperamide, opium derivatives. - **Pharmacodynamics**: - Bismuth subsalicylate works on the GI lining to inhibit local reflexes. - Loperamide acts directly on the muscles of the GIT to slow activity. - Opium derivatives affect CNS centers to slow GI activity. - **Uses**: Treat acute and chronic diarrhea, reduce discharge from ileostomies, prevent and treat traveler's diarrhea. - **Adverse Effects**: - GI: Constipation, nausea, dry mouth, abdominal discomfort. - CNS: Fatigue, weakness, dizziness, skin rash. - Opium derivatives may cause sedation, euphoria, hallucinations, and respiratory depression. **1. Antihistamine Drugs (\"For Allergy\")** - **Mechanism**: Block the action of histamine, the chemical responsible for allergy symptoms like itching, swelling, and inflammation. - **Pharmacokinetics**: Rapid absorption within 15 minutes. - **Contraindications**: Not used for treating anaphylaxis. **Types of Antihistamines:** 1. **First-generation antihistamines**: - Older, more sedating (e.g., diphenhydramine - Benadryl, chlorpheniramine). - Cause drowsiness and central nervous system (CNS) side effects. 2. **Second-generation antihistamines**: - Newer, less sedating (e.g., cetirizine - Zyrtec, loratadine - Claritin, fexofenadine - Allegra). - Fewer side effects and are considered safer. **Uses:** - **Allergic Rhinitis (Hay Fever)**: Relieve sneezing, itchy/watery eyes, nasal congestion. - **Hives and Skin Allergies**: Reduce itching, swelling, and redness. - **Motion Sickness**: Some antihistamines (e.g., dimenhydrinate - Dramamine) prevent motion sickness. - **Insomnia**: First-generation antihistamines (e.g., diphenhydramine) are used as sleep aids due to their sedative effects. **Side Effects:** - **Drowsiness and sedation** (especially with first-generation). - **Dry mouth, nose, and throat**. - **Dizziness, impaired coordination**. - **Constipation** **2. Antitussive Drugs (\"Suppress Cough\")** - **Mechanism**: Suppress or reduce coughing by acting on the cough reflex in the medulla oblongata. - **Types**: 1. **Non-narcotic** (e.g., dextromethorphan). 2. **Narcotic** (e.g., codeine, hydrocodone). 3. **Combination**: Narcotic and non-narcotic. **Mechanism of Action:** - **Central action**: Depress the cough center in the brain to decrease cough reflex sensitivity. - **Peripheral action**: Act on the respiratory system to inhibit the cough response (e.g., benzonatate). **Common Antitussives:** - **Codeine**: A narcotic that acts on the CNS. - **Dextromethorphan (DXM)**: A non-narcotic that acts centrally. - **Guaifenesin**: A peripheral antitussive that loosens mucus. - **Benzonatate**: Numbs the cough reflex. **Uses:** - **Dry, unproductive cough**. - **Short-term cough suppression** to improve sleep and quality of life. **Side Effects:** - **CNS effects**: Drowsiness, dizziness, impaired coordination. - **GI effects**: Constipation, nausea, vomiting. - **Respiratory depression** (especially with narcotics). - **Addiction potential** (narcotic antitussives like codeine) **3. Asthma Drugs** A. **Methylxanthines** (\"Bronchodilators\"): - **Example**: Theophylline. - **Therapeutic Range (TR)**: 10-20 mcg/ml. - **Uses**: Chronic stable asthma, COPD. - **Contraindications**: Seizures, cardiac issues, liver disease. - **Onset**: 30 mins, **Duration**: 6 hours (oral & IV), 8-24 hours (sustained release). - **Important**: Avoid caffeine. IV administration must be slow to prevent dizziness, hypotension, flushing, bradycardia, and palpitations. B. **Pirbuterol**: - Aerosolized bronchodilator used alongside theophylline or steroid therapy. C. **Cromolyn Sodium**: - **Use**: Prevents bronchial or acute asthma by inhibiting histamine release. - **Administration**: By inhalation. **4. Mucolytics (\"Liquefy and Loosen Thick Mucus\")** - **Use**: Help clear mucus in conditions like cystic fibrosis and chronic bronchitis. A. **Acetylcysteine**: - **Administration**: Nebulization or oral (diluted). - **Uses**: Asthma, hyperactive airway, antidote for acetaminophen overdose (if given within 12-24 hours). - **Side Effects**: Nausea, vomiting, stomatitis, runny nose. B. **Dornase Alfa**: - **Mechanism**: Enzyme that digests DNA in thick sputum (used in cystic fibrosis). - **Effect**: Improvement within 3-7 days. - **Side Effects**: Chest pain, sore throat, laryngitis, hoarseness. **Uses of Mucolytics:** - **COPD**. - **Cystic Fibrosis**: Liquefy thick mucus. - **Bronchitis** (acute and chronic). - **Pneumonia**. - **Atelectasis**. **Side Effects:** - **GI effects**: Nausea, vomiting, abdominal pain, diarrhea. - **Respiratory effects**: Cough, bronchospasm, throat irritation. - **Allergic reactions**: Rash, hives, angioedema. - **Metabolic effects**: Electrolyte imbalances (e.g., hypokalemia). **5. Expectorants (\"Thinning of Mucus\")** - **Mechanism**: Help loosen and expel mucus from the lungs. **Common Drugs:** - **Guaifenesin** (Mucinex, Robitussin): Loosens mucus. - **Tessalon Perles (Benzonatate)**: Thins mucus. - **Ammonium chloride**. - **Potassium iodide** **CENTRAL & PERIPHERAL NERVOUS SYSTEM DRUGS** **1. Muscle Relaxants** - **Purpose**: These drugs help relieve muscle pain, spasms, and tightness caused by conditions like Multiple Sclerosis (MS), cerebral palsy, and injuries. - **Types**: 1. **Centrally-acting** (work on the brain and spinal cord): - **Examples**: Baclofen, Cyclobenzaprine, Methocarbamol. - **Used for**: Short-term relief from muscle spasms due to injury, pain, or anxiety. - **Side effects**: Drowsiness, dizziness, dry mouth, and sometimes changes in urine color. 2. **Peripherally-acting** (work directly on the muscles): - **Example**: Dantrolene Sodium. - **Used for**: Treating severe muscle stiffness in conditions like MS and preventing a serious condition called malignant hyperthermia. - **Caution**: Can harm the liver, especially when combined with other drugs like estrogen. **2. Sedatives, Anxiolytics (Anti-Anxiety), and Hypnotics (Sleep Aids)** - **Purpose**: These drugs calm you down, reduce anxiety, and help you sleep. - **Types**: 1. **Benzodiazepines**: Reduce anxiety, help you relax, and are sometimes used to stop seizures. - **Examples**: Lorazepam (Ativan), Temazepam. - **Side effects**: Drowsiness, confusion, and risk of dependence if used long-term. 2. **Barbiturates**: Older sedatives that are now used less because they can be addictive and cause serious breathing problems. - **Examples**: Phenobarbital. 3. **Nonbenzodiazepines**: Newer sleep aids with fewer side effects but still help with short-term insomnia. - **Examples**: Zolpidem (Ambien). **3. Anti-Anxiety Drugs (Anxiolytics)** - **Buspirone**: A newer anti-anxiety drug with fewer side effects than older ones. - **Advantages**: Doesn't cause much drowsiness, and it's not addictive. However, it takes time to start working, so it's not for immediate relief. **4. Antidepressants** - **Purpose**: Treat depression by balancing chemicals in the brain. - **Types**: 1. **MAO Inhibitors (MAOIs)**: Increase levels of norepinephrine and serotonin in the brain. They are powerful but require a strict diet. - **Example**: Phenelzine. - **Warning**: Avoid foods like cheese and red wine as they can cause dangerous reactions. 2. **Tricyclic Antidepressants (TCAs)**: Help increase norepinephrine and serotonin but can cause dry mouth, weight gain, and drowsiness. - **Examples**: Amitriptyline, Imipramine. 3. **Selective Serotonin Reuptake Inhibitors (SSRIs)**: Newer drugs with fewer side effects, often used for both depression and anxiety. - **Examples**: Fluoxetine (Prozac), Sertraline (Zoloft). **5. Antiparkinsonian Agents** - **Purpose**: Help manage the symptoms of Parkinson's disease, like tremors and stiffness. - **Types**: 1. **Dopaminergic Drugs**: Increase dopamine levels in the brain, which are low in Parkinson's. - **Examples**: Levodopa, Carbidopa-Levodopa (Sinemet). - **Caution**: Can cause nausea, low blood pressure, and confusion. 2. **Anticholinergic Drugs**: Reduce the activity of acetylcholine, another brain chemical that's too active in Parkinson's patients. - **Examples**: Benztropine. **6. Antiepileptic Drugs (Anticonvulsants)** - **Purpose**: Prevent seizures in epilepsy or after head injuries. - **Types**: 1. **Hydantoins**: Control seizures by stabilizing brain activity. - **Example**: Phenytoin (Dilantin). 2. **Barbiturates**: Used to treat seizures but can cause drowsiness. - **Example**: Phenobarbital. 3. **Benzodiazepines**: Also used to control seizures (e.g., Diazepam). 4. **Valproic Acid**: A broad-spectrum anticonvulsant used for different types of seizures. - **Caution**: Can cause liver problems, especially in young children. **7. Antipsychotic Agents** - **Purpose**: Treat psychotic conditions like schizophrenia, where patients may have delusions or hallucinations. - **Types**: 1. **Typical Antipsychotics**: Older drugs that help with the positive symptoms (hallucinations, delusions) but can cause movement disorders (tremors, stiffness). - **Examples**: Haloperidol, Chlorpromazine. 2. **Atypical Antipsychotics**: Newer drugs that treat both positive and negative symptoms (e.g., lack of motivation) with fewer movement side effects. - **Examples**: Risperidone, Clozapine **DRUGS ACTING ON THE RENAL SYSTEM** **Diuretics ***" Diuretics think DRY INSIDE"* Diuretics are crucial medications that facilitate the excretion of water and electrolytes through the kidneys. Their primary functions are to lower blood pressure and reduce edema associated with conditions such as heart failure and renal or liver disorders. **The main classes of diuretics include:** \- Thiazide and Thiazide-like \- Loop Diuretics \- Potassium-sparing Diuretics \- Osmotic Diuretics \- Carbonic Anhydrase Inhibitors **Thiazide and Thiazide-like Diuretics** These diuretics are derivatives of sulfonamide and include: **Thiazides**: \- Bendroflumethiazide \- Benzthiazide \- Chlorothiazide \- Hydrochlorothiazide \- Hydroflumethiazide \- Methyclothiazide \- Polythiazide \- Trichlormethiazide \- **Thiazide-like:** \- Chlorthalidone \- Indapamide **Loop Diuretics** Known as high-ceiling diuretics, they act on the thick ascending loop of Henle to inhibit sodium chloride transport into circulation. Key examples include: \- Bumetanide \- Ethacrynate sodium \- Ethacrynic acid \- Torsemide \- Furosemide **Potassium-sparing Diuretics** These diuretics have milder effects compared to others but help conserve potassium. Common examples are: \- Amiloride \- Spironolactone \- Triamterene **Osmotic Diuretics** Osmotic diuretics draw water into the renal tubule without causing sodium loss. A prominent example is mannitol. They are particularly useful in acute situations, such as: \- Reducing intraocular pressure (IOP) before eye surgery or during glaucoma attacks. \- Managing increased intracranial pressure (ICP) or acute renal failure due to shock, drug overdose, or trauma. **Carbonic Anhydrase Inhibitors** These mild diuretics include: \- Acetazolamide \- Methazolamide **Drugs for Fluids and Electrolytes** **Electrolyte Management** - Fluid and electrolyte balance can be easily disrupted by illness, loss of appetite, medication, vomiting, surgery, and diagnostic tests. Electrolytes are compounds that carry an electrical charge when dissolved in water, and electrolyte replacement drugs are mineral salts that help restore depleted levels. **Key Electrolytes** **Potassium** \- Major cation in intracellular fluid (ICF). \- Normal levels: 3.5 to 5.5 mEq/L. \- Dietary requirement: 40-60 mEq daily. \- Supplementation can be done orally or intravenously using potassium salts like potassium bicarbonate, chloride, gluconate, and sulfate. **Calcium** \- Primarily stored in bones; mobilized as needed. \- Chronic deficiency can lead to bone demineralization. \- Normal levels: 4.5 to 5.5 mEq/L or 8.5 to 10.5 mg/dl. \- Daily requirements vary by age: \- 1,300 mg (ages 14--18) \- 1,000 mg (ages 19--50) \- 1,200 mg (over age 50). **Magnesium** \- Second most abundant cation in ICF after potassium. \- Normal levels: 1.5 to 2.5 mEq/L. \- Daily requirements: \- Ages 19--30: 400 mg (men), 310 mg (women) \- Over age 31: 420 mg (men), 320 mg (women). **Sodium** \- Major cation in extracellular fluid (ECF). \- Normal levels: 135 to 145 mEq/L. \- Daily dietary requirement: approximately 2 g.