pharmacy all semester notes and study material previous year qus

LAXATIVES 1. Bulk-Forming Laxatives (Fiber Supplements) ✅ Mechanism: Absorb water to increase stool bulk and soften it. ⏳ Onset: 12–72 hours. 💊 Examples: Psyllium (Metamucil) Methylcellulose (Citrucel) Polycarbophil (FiberCon) Wheat dextrin (Benefiber) --- 2. Osmotic Laxatives ✅ Mechanism: Draw water into the intestines, softening stool and promoting bowel movements. ⏳ Onset: 30 minutes to 3 days (depends on type). 💊 Examples: Polyethylene glycol (PEG 3350) – (MiraLAX, GlycoLax) Lactulose – (Constulose, Kristalose) Sorbitol – Sugar alcohol with a mild laxative effect. Magnesium hydroxide (Milk of Magnesia) Magnesium citrate – Used for rapid bowel cleansing. --- 3. Stimulant Laxatives ✅ Mechanism: Stimulate intestinal contractions to move stool. ⏳ Onset: 6–12 hours. 💊 Examples: Senna (Sennosides) – (Senokot, Ex-Lax) Bisacodyl – (Dulcolax, Correctol) Castor oil – (Less commonly used due to cramping effects) --- 4. Stool Softeners (Emollients) ✅ Mechanism: Increase water and fat penetration in stool, making it easier to pass. ⏳ Onset: 12–72 hours. 💊 Examples: Docusate sodium (Colace) Docusate calcium (Surfak) --- 5. Lubricant Laxatives ✅ Mechanism: Coat stool to prevent water loss, making it easier to pass. ⏳ Onset: 6–8 hours. 💊 Examples: Mineral oil – Available as oral liquid or enema. --- 6. Prokinetic & Secretory Agents (For Chronic Constipation or IBS-C) ✅ Mechanism: Stimulate gut motility and fluid secretion. 💊 Examples: Lubiprostone (Amitiza) – Chloride channel activator. Linaclotide (Linzess) – Guanylate cyclase-C agonist, increases intestinal fluid. Plecanatide (Trulance) – Similar to Linzess. Prucalopride (Motegrity) – Serotonin (5-HT4) receptor agonist, enhances gut motility. --- 7. Enemas & Suppositories ✅ Mechanism: Provide direct stool softening and evacuation. ⏳ Onset: Minutes to hours. 💊 Examples: Glycerin suppositories – Mild stimulant effect. Bisacodyl suppositories – Faster-acting stimulant. Phosphate enema (Fleet Enema) – Used for rapid relief.

𝗖𝗲𝘁𝗶𝗿𝗶𝘇𝗶𝗻𝗲 ✅ 𝗖𝗲𝘁𝗶𝗿𝗶𝘇𝗶𝗻𝗲 is a 𝘀𝗲𝗰𝗼𝗻𝗱-𝗴𝗲𝗻𝗲𝗿𝗮𝘁𝗶𝗼𝗻 𝗛𝟭 𝗮𝗻𝘁𝗮𝗴𝗼𝗻𝗶𝘀𝘁, used for allergic rhinitis and urticaria. ✅ 𝗟𝗲𝘀𝘀 𝘀𝗲𝗱𝗮𝘁𝗶𝗼𝗻 compared to first-generation antihistamines. ✅ The standard pediatric dose (6–12 years) is 5 mg once daily, while adults receive 10 mg once daily. ✅ Starts 𝘄𝗼𝗿𝗸𝗶𝗻𝗴 𝗶𝗻 𝟯𝟬–𝟲𝟬 𝗺𝗶𝗻𝘂𝘁𝗲𝘀 and lasts 24 hours. ✅ Excreted by kidneys → 𝗱𝗼𝘀𝗲 𝗮𝗱𝗷𝘂𝘀𝘁𝗺𝗲𝗻𝘁 𝗻𝗲𝗲𝗱𝗲𝗱 in renal impairment. ✅ 𝗦𝗮𝗳𝗲𝗿 𝗶𝗻 𝗲𝗹𝗱𝗲𝗿𝗹𝘆 𝗽𝗮𝘁𝗶𝗲𝗻𝘁𝘀 due to fewer anticholinergic effects.