Pharmacology 💊 Flashcards

Question

what are the adverse effects of senna?

Answer 1

1. It passes in urine and cause urine discoloration 2. It passes in breast milk and cause cathartic effect in the baby.

Answer 2

- It is prepared as enteric coated tablets to avoid gastric irritation. - If it is given with milk or with other drugs that change gastric pH, - the enteric coating may dissolve in the stomach and cause gastric irritation and pain.

Answer 3

they are anionic surfactants that enable additional water and fats to be incorporated in the stool, making it easier to move through the GIT.

Answer 4

* Glycerin has hygroscopic effect. It draws water from rectal mucosa and lubricates the anal canal. * It also stimulates reflex rectal contractions and promotes stool evacuation in 15-20 min. * Evacuant enema (tape water with mineral oil, hypertonic sorbitol, MgSO4) are safe for administration to facilitate passage of stool in painful anal conditions.

Answer 5

* It acts by activating chloride channels to increase fluid secretion in the intestinal lumen. * This eases the passage of stool and causes little change in electrolyte balance.

Answer 6

treatment of chronic constipation, irritable bowel syndrome (IBS)

Answer 7

* tolerance or dependency has not been associated with this drug. * Also, drug– drug interactions appear minimal

Answer 8

* Constipation: laxatives should not be used for prolonged duration to avoid laxative dependence. * To fasten excretion of toxic substances from the GIT. * To prepare the bowel before X-ray or colonoscopy. * Hepatic encephalopathy (lactulose): to kill ammonia producing bacteria. * Painful anal conditions e.g. anal fissure or piles. * Postoperative: e.g. after hemorrhoids (piles) to avoid strain.

Answer 9

* Laxatives are dangerous in cases of undiagnosed abdominal pain or inflammatory bowel disease. They may lead to intestinal perforation. * Organic obstruction of the GIT.

Answer 10

Drugs used to decrease passage of frequent unformed stool.

Answer 11

1. Anti-cholinergic drugs:(Atropine, hyoscine and propantheline) 2. Synthetic opioids: diphenoxylate and loperamide

Answer 12

Blocking M3 receptor in intestinal smooth muscle: ✓ ↓ colonic peristalsis: Antidiarrheal action ✓ Relieve cramps associated with diarrhea: Antispasmodic action

Answer 13

* They act on opioid μ (mu) receptors enteric nervous system (ENS) leading to ↑ segmenting (non-propulsive) contractions of the intestine and increase resistance to flow through the lumen. * They act on opioid δ (delta) receptors in the ENS leading to ↑ water absorption and ↓ water secretion. * They act on presynaptic opioid receptors in the ENS leading to ↓ Ach release.

Answer 14

Loperamide cannot cross BBB but diphenoxylate can cross BBB poorly (no CNS effects in usual therapeutic doses) but it can cause addiction if used in large doses and for prolonged duration.

Answer 15

Lomotil is a combination of diphenoxylate 2.5 mg + atropine 0.25 mg: produce more ↓↓ in intestinal motility and decrease liability for abuse.

Answer 16

* Anti-cholinergic side effects. * Addiction: if used for prolonged duration.

Answer 17

1. Maintenance of fluid and electrolyte balance 2. Non-specific antidiarrheal agents (should be applied after exclusion of other relevant causes of diarrhea) 3. Specific antidiarrheal agents: treatment of the cause

Answer 18

- Is the first priority especially in extreme of age. - Using oral Rehydration Therapy (ORT): Balanced salt solution containing electrolytes and glucose - Or Intravenous solutions: in severe dehydration.

Answer 19

* Drugs decrease lower GIT motility * Drugs bind to toxins as Adsorbents(Kaolin, pectin, activated charcoal) or bind bile acid as cholestyramine

Answer 20

- antimicrobials for infectious diarrhea. - Anti-inflammatory drugs for inflammatory bowel diseases.

Answer 21

* Anticholinergic drugs: atropine, propantheline, hyoscine * Direct smooth muscle relaxants: papaverine, mebeverine, alverine, drotaverine. * Mixtures: Librax (clidinium + chlordiazepoxide).

Answer 22

* Papaverine: natural opium alkaloid * Mebeverine, alverine, drotaverine: synthetic drugs

Answer 23

Inhibition of PDE enzyme lead to increase cAMP and smooth muscle relaxation

Answer 24

Spasms of the GIT, bile duct and genitourinary tract.

Answer 25

- Cardiac arrhythmia. - Abnormal liver functions in the form of ↑ serum transaminases and alkaline phosphatase. - Headache and dizziness

Answer 26

* Paralytic ileus. * Constipation for more than one week

Answer 27

* Chlordiazepoxide: benzodiazepine that has antianxiety effect. * Clidinium:anticholinergic drug which ↓ GIT motility

Answer 28

* Spasms of the GIT, bile duct and genitourinary tract. * Treatment of irritable bowel syndrome (IBS).

Answer 29

* Atropine-like actions e.g, dry mouth, urine retention, etc. * CNS depression (benzodiazepine): Sedation, drowsiness, confusion, etc.

Answer 30

as direct smooth muscle relaxant: * Paralytic ileus. * Constipation for more than one week.

Answer 31

- **Ulceration of the duodenum or stomach** due to **imbalance** between local invasive force (e.g. HCl and pepsin) and protective mechanisms.

Answer 32

**- Stress:**↑ HCl and pepsin secretion by parietal cells. **- Diet:** coffee, alcohol and spices. **- Drugs:** NSAIDs, corticosteroids, morphine,methylxanthines, etc. - Infection with **Helicobacter pylori.**

Answer 33

- **Mucus** production by gastric mucosa. - Pancreatic **bicarbonate** secretion. - Good mucosal **blood flow**. - Local **PGE2 and PGI2** production.

Answer 34

- H. pylori is spiral gram **-ve flagellates** found in the **antrum** of human stomach

Answer 35

- Infection with H. pylori can be diagnosed by **endoscopic biopsy or serological markers**.

Answer 36

- **Ach:** ↑ HCl secretion through M1 receptors → ↑ intracellular Ca2+. - **Gastrin:** ↑ HCl secretion through G receptors → ↑ intracellular Ca2+. - **Histamine:** ↑ HCl secretion through H2 receptors → ↑ intracellular **cAMP**. - Both **Ca2+ and cAMP activate H+/K+ ATPase** at the membrane of the parietal cell to secrete H+ into the gastric lumen (proton pump).

Answer 37

act on PG receptors → ↓ cAMP → ↓ HCl secretion.

Answer 38

- Rest and Sedation: they improve healing and relief pain of DU. - Stop Smoking, Spices, alcohol, coffee, and tea: because they ↑ HCl. - Avoid Stress: because stress ↑ HCl. - Avoid ulcerogenic drugs: e.g. NSAIDs. - Diet: 1. Frequent small meals in DU in order to buffer high acidity. 2. Encourage milk and fats. 3. Avoid Spices and fried food

Answer 39

(Cimetidine – Ranitidine – Famotidine - Nizatidine)

Answer 40

**Drugs that ↓ HCl secretion (Antisecretory drugs):** - H2 blockers: cimetidine, ranitidine, famotidine. - Proton pump inhibitors: omeprazole, lanzoprazole, etc. **Drugs that ↑ mucosal defense mechanisms (cytoprotective drugs):** - Sucralfate - Colloid bismuth compounds: e.g. bismuth subcitrate. - Carbenoxolone - PGE1 analogues: misoprostol. **Drugs that neutralize HCl:** - antacids **Antimicrobial drugs for H. pylori**

Answer 41

- They act as **competitive inhibitors of histamine H2-receptors** on the parietal cell, This results in a marked ↓ in **histamine-stimulated HCl secretion**

Answer 42

- Duodenal and gastric ulcers. - Prophylaxis & treatment of stress ulcers (e.g. after burn or major trauma). - Reflux esophagitis. - With ulcerogenic drugs (e.g. NSAIDs) to protect the gastric mucosa from injury.

Answer 43

- GIT disturbance - CNS symptoms: headache, slurred speech, delirium, coma, etc. - Tolerance - Cimetidine has **anti-androgenic effects** (due to block of androgen receptors) leading to **↓ sperm count, impotence and gynecomastia**. - Cimetidine **inhibits hepatic microsomal enzymes** (P450) leading to ↓ metabolism of other drugs e.g. **theophylline, warfarin, sulphonylureas, etc.**

Answer 44

- **Avoid sudden withdrawal** to prevent rebound ulceration. - **Avoid combination** of cimetidine with **drugs having narrow therapeutic index** (because cimetidine inhibits microsomal P450 and ↑ their toxicity).

Answer 45

(Omeprazole – Lansoprazole – Pantoprazole)

Answer 46

- They are **prodrugs**, They are converted into the active form in the **gastric mucosa** - Produce **irreversible inhibition of gastric H+/K+ ATPase enzyme** leading to **↓ both basal and stimulated HCl** secretion to around the zero level for **1-2 days**. - Their **bioavailability is decreased significantly by food** and, ideally, should be administered **1 hour before a meal**.

Answer 47

**The same as H2 blockers** (dose of omeprazole: 20-40 mg/day orally for 4-6 weeks then 10-20 mg/day for 4-6 months to prevent recurrence).

Answer 48

- GIT disturbance: abdominal colic, nausea, vomiting and transient increase of liver enzymes. - Headache, dizziness, skin rash, - **Decrease vit B12 absorption** after > 12 weeks of therapy due to interference with intrinsic factor secretion by the stomach **(megaloblastic anemia)**. - Osteoporosis - **Inhibition of gastric acidity** leads to alteration of bioavailability of some drugs e.g. **ketoconazole, digoxin, and iron**. - Infection eg, RT pneumonia, C. diffecil infection - Omeprazole in high dose induced gastric carcinoid tumor in rats. **Drug interaction:** - PPI (Omeprazole) inhibits microsomal P450 enzymes leading to: 1. Decreases metabolism of some drugs and increase their toxicity eg, phenytoin, warfarin. 2. Decrease activation of clopidogrel.

Answer 49

- It **needs acidic medium** to be activated. In the presence of acidic medium, it forms a **complex with protein debris at the ulcer base and forms a physical barrier** (so not taken with antacids, H2 blockers, or PPIs). - It **↓ pepsin secretion and ↑ secretion of endogenous PGs**.

Answer 50

- **Constipation** (due to presence of aluminum). - **↓↓ absorption of tetracycline, digoxin and phenytoin**. - Contain aluminum metal which may accumulate in cases of renal failure causing toxicity, so it should be avoided in **renal failure**.

Answer 51

Bismuth subsalicylate and subcitrate

Answer 52

- As sucrlfate - It has additional antimicrobial activity against H. pylori.

Answer 53

- Black stool and teeth discoloration. - Encephalopathy in presence of renal failure

Answer 54

Chronic renal failure and CNS diseases.

Answer 55

Misoprostol

Answer 56

- It acts on specific receptors on gastric parietal cells to **↓ histamine-stimulated HCl secretion**. - **↑ mucus and bicarbonate secretion** (cytoprotective action). - **↑ mucosal blood flow** and stimulates mucosal cellular regeneration.

Answer 57

**Prevention** of peptic ulcer in high risk patients e.g. those on long term use of NSAIDs for chronic inflammatory diseases. [misoprostol 200 microgram is combined with naproxen or diclofenac in single tablet].

Answer 58

- Diarrhea and cramping pain: due to ↑ GIT motility and water secretion. - Uterine contractions during pregnancy → abortion.

Answer 59

Antacids are **weak bases** that are taken **orally** and partially **neutralize gastric acid and reduce pepsin activity**.

Answer 60

They are used as **symptomatic relief of hyperacidity** and should **not** be used as **long-term treatment**.

Answer 61

- Sodium bicarbonate - Calcium carbonate - Magnesium and aluminum salts (Mg hydroxide and Aluminium hydroxide)

Answer 62

**Change in bowel habits:** - **Al3+** hydroxide causes **constipation**, while **Mg2+** hydroxide cause **diarrhea**. For this reason, **both salts** are combined **together** to manage this problem. **Rebound hyperacidity:** - with **Ca2+ and Na**HCO3 containing antacids. **Cation overload:** - Na+ salts → hypertension and systemic alkalosis. - Ca2+ salts → hypercalcemia, renal stones . **Decrease absorption of other drugs:** - the metal ion in some preparations can chelate other drugs especially **tetracycline, digitalis and iron** (2 hours interval is essential)

Answer 63

Infection with **H. pylori** is a main cause of recurrence of PU.

Answer 64

- **H**ospitalization and Fresh blood transfusion. - **A**cid suppression with high dose PPIs by continuous i.v. infusion is the standard of care e.g. omeprazole 80 mg i.v. bolus followed by 8 mg/h for 72h. - **V**itamin K1: 10 mg i.m or s.c. - **E**ndoscopic therapy: several types of endoscopic treatments are available

Answer 65

- It is the syndrome consisting of **esophageal mucosal damage** produced by **retrograde** flow of gastric contents into the esophagus. - It is primary due to **ineffective or incompetent** lower esophageal sphincter **(LES)**.

Answer 66

Non- Drug Measures: - **Sleeping on a high pillow:** most damage to the esophagus occurs at night when swallowing is much reduced and acid can remain in contact with the mucosa of the esophagus for long period. - **Avoid:** 1. Large meals and eating before sleeping. 2. Alcohol, smoking, spicy foods and coffee. 3. Aspirin and NSAIDs. 4. Tight clothes around the abdomen. 5. Weight reduction (Enhance, Don’t avoid) **--------------------------------------------------------------------------** Drug treatment: - Decreasing HCl secretion: (H2 blockers and proton pump inhibitors). - Antacids and antacid combinations:(Gaviscon). - Prokinetic drugs. - Surgical treatment: if medical therapy failed.

Answer 67

(alginic acid + Mg-trisilicate + Al-hydroxide + NaHCO3)

Answer 68

Alginic acid **in presence of saliva and NaHCO3** forms a highly **viscous foamy solution** of Na-alginate that **floats on the gastric contents as a raft and prevents gastric reflux**.

Answer 69

Drugs that increase upper GIT motility and increase gastric empting.

Answer 70

**1. Dopaminergic blockers:** e.g. Metoclopramide and Domperidone. **2. Serotonin (5-HT4) agonists:** e.g. Mosapride **3. Cholinomimetic agents:** e.g. Bethanechol. **4. Macrolide antibiotics:** e.g.Erythromycin

Answer 71

1. Misoprostol 2. PPI 3. H2 Blockers