Pharmacology Review – GI, GU, Endocrine, CNS & Related Agents

Chapter 50 – Acid-Controlling Drugs

ANTACIDS

• Basic salts (Al, Mg, Ca, Na); neutralise gastric HCl – do not ↓ acid production.

• Often combined with simethicone (antiflatulent).

• Mg → diarrhoea ; Al/Ca → constipation ; combo products balance bowel effects.

• Serious concerns: rebound hyper-acidity (esp. Ca), hyper-calcaemia, milk-alkali syndrome, metabolic alkalosis, acid rebound.

• Caution: Na-containing preps in HF/HTN/Na-restricted pts.

• Drug-interaction mechanisms

  • Adsorption, chelation, ↑ gastric pH (↑ basic drug absorption/↓ acidic), ↑ urinary pH (↑ excretion of acidic drugs).

  • Avoid other PO meds within 1 – 2 h; major risk with quinolones (≈ 50 % ↓ absorption).

H₂-RECEPTOR ANTAGONISTS (H2RA)

• Cimetidine, famotidine, nizatidine (ranitidine withdrawn 2020).

• Block H₂ on parietal cell → up to 90 % ↓ H⁺ secretion → ↑ pH.

• Uses: GERD, PUD, erosive oesophagitis, stress-bleed adjunct, ZE-syndrome.

• Cimetidine: strong CYP-450 inhibitor → ↑ levels of warfarin, phenytoin, theophylline etc.

• All OTC. IV infusion → watch hypotension.

PROTON-PUMP INHIBITORS (PPI)

• Omeprazole, esomeprazole, pantoprazole, lansoprazole, dexlansoprazole, rabeprazole; Zegerid = omeprazole + NaHCO₃.

• Irreversibly inhibit H⁺/K⁺-ATPase → block all acid secretion.

• 1st-line: erosive oesophagitis, severe GERD, NSAID-ulcers, ZE-syndrome, stress-ulcer prophylaxis; combo Tx for H. pylori.

• Interactions: ↓ activation of clopidogrel (omeprazole via CYP2C19); ↑ diazepam, phenytoin; ↑ bleed risk with warfarin.

• FDA warnings: long-term/high-dose → C. difficile, fractures (hip/wrist/spine), pneumonia, hypomagnesaemia.

MISCELLANEOUS

• Sucralfate: forms protective barrier on ulcers.

• Misoprostol: PGE₁ analogue – prevents NSAID ulcers.

• Simethicone: reduces surface tension → gas bubbles coalesce.

NURSING HIGHLIGHTS

• Complete GI & med history (incl. OTC/herbals); assess Na load, renal/cardiac status.

• Give antacids with 240 mL water; chew tabs thoroughly.

• Separate antacids & other PO drugs 1–2 h.

• Monitor occult blood, black/tarry stool; report hematemesis.

• PPIs: give 30–60 min before meals; monitor Mg²⁺, Ca²⁺, bone density.

Chapter 51 – Lower-GI Drugs

ANTIDIARRHEALS

• Adsorbents: bismuth subsalicylate (A/E: ↑ bleed, dark stools/tongue), activated charcoal, colestipol/cholestyramine.

• Anticholinergics: atropine, hyoscyamine – ↓ peristalsis, drying; A/E: urinary retention, blurred vision, confusion.

• Opiates: loperamide, diphenoxylate/atropine – ↓ motility, relieve spasm; additive CNS depression.

• Probiotics (Lactobacillus) – restore flora.

LAXATIVES

• Bulk-forming: psyllium, methylcellulose – absorb water → distend bowel; safest for long-term; take with ≥ 240 mL water.

• Emollient: docusate (stool softener), mineral oil (lubricant) – water/fat into stool.

• Hyper-osmotic: lactulose, PEG, glycerin – ↑ water in colon; lactulose also ↓ ammonia.

• Saline: Mg citrate, Mg hydroxide – osmotic water influx; rapid (3–6 h).

• Stimulant: senna, bisacodyl – nerve stimulation → peristalsis; risk of dependence.

• Peripheral μ-opioid antagonists for OIC: methylnaltrexone, alvimopan, naloxegol.

IBS DRUGS

• IBS-D: alosetron (5-HT₃ antag, BBW ischaemic colitis), rifaximin (non-abs ABx), eluxadoline (μ/κ agonist, δ antag).

• IBS-C: lubiprostone (Cl⁻ channel activator), linaclotide (guanylate cyclase-C agonist), tegaserod (5-HT₄ agonist – CV risk).

NURSING

• Baseline bowel pattern, hydration, electrolytes; auscultate BS 4 quadrants.

• Older adults → ↑ risk fluid/electrolyte loss.

• Avoid bismuth subsalicylate in children/teens (Reye’s) & ASA allergy.

• Encourage fibre, fluids, activity; caution laxative abuse.

Chapter 52 – Antiemetics/Antinausea

CLASSES & MECHANISMS

• Anticholinergics: scopolamine – block vestibular ACh.

• Antihistamines (H₁): dimenhydrinate, meclizine, hydroxyzine (IM/PO only) – block vestibular H₁.

• Dopamine antagonists: prochlorperazine, promethazine (IV risky – tissue necrosis), metoclopramide (also prokinetic) – CTZ block.

• Neurokinin-1 antagonists: aprepitant, fosaprepitant, rolapitant – block substance P; 3A4 interactions.

• 5-HT₃ antagonists: ondansetron, granisetron – CTZ & GI serotonin block; 1st-line CINV.

• Tetrahydrocannabinol: dronabinol – cortical inhibition; CINV, appetite.

SAFETY & NURSING

• Contra scopolamine in narrow-angle glaucoma.

• Give antiemetic 30–60 min before chemo.

• Monitor orthostatic BP, dehydration, extrapyramidal sx (metoclopramide – tardive dyskinesia).

• Warn about drowsiness; avoid driving.

Chapter 28 – Diuretics

CARBONIC ANHYDRASE INHIBITORS (CAI)

• Acetazolamide – ↓ H⁺ avail → HCO₃⁻ diuresis; uses: glaucoma, altitude sickness, edema.

• A/E: metabolic acidosis, hypokalaemia, hyperglycaemia.

LOOP DIURETICS

• Furosemide, bumetanide, torsemide – block Na⁺/Cl⁻ in thick ascending loop; rapid, potent even at CrCl < 25 mL/min.

• Uses: edema HF/renal/hepatic, HTN, hypercalcaemia.

• A/E: hypokalaemia, ototoxicity, dehydration, ↑ glucose/uric acid; furosemide BBW fluid-electrolyte loss.

OSMOTIC

• Mannitol – proximal tubule; ↓ ICP/IOP, ARF prophylaxis; A/E: pulmonary edema, convulsions.

POTASSIUM-SPARING

• Spironolactone, amiloride, triamterene – collect. duct; aldosterone antagonism.

• Uses: hyperaldosteronism, HF, counter K⁺ wasting.

• A/E: hyperkalaemia, gynecomastia (spirono), kidney stones (triam). BBW spirono tumor.

THIAZIDE(+-like)

• HCTZ, chlorthalidone, indapamide, metolazone – distal tubule Na-Cl blocker; ineffective CrCl < 30 (except metolazone).

• 1st-line HTN; also diabetes insipidus, Ca²⁺ stones.

• A/E: hypo-K/Na/Mg, hyper-Ca/lipids/uric acid/glucose, photosensitivity.

NURSING

• Baseline weight, I&O, BP, electrolytes, renal/hepatic fx.

• Dose in AM; change positions slowly.

• Monitor K⁺: supplements with loops/thiazides; avoid with K-sparing/ACE.

• Assess ototoxic meds with loops.

Chapter 29 – Fluids & Electrolytes

CRYSTALLOIDS

• 0.9 % NaCl, LR, D5W, etc. Replace water/Na⁺; can cause edema, dilute COP.

• Hypertonic (3–5 % NaCl) – cautious, risk ODS.

COLLOIDS

• Albumin 5 %, dextran 40, hetastarch – ↑ oncotic pressure; risk coagulopathy, anaphylaxis.

BLOOD PRODUCTS

• PRBCs, FFP, cryo; only fluid with O₂-carrying ability; infuse with NS only.

POTASSIUM

• HypoK < 3.5 mEq/L (weakness, arrhythmia); HyperK > 5.5 (paresthesia, VF).

• IV KCl: max 10 mEq/h (unmonitored); high-alert.

• Treat hyperK: patiromer, sodium zirconium, insulin + glucose, Ca²⁺, dialysis.

SODIUM

• HypoNa < 135 mEq/L (seizure, cramps); risk ODS with rapid correction.

• HyperNa > 145 mEq/L (edema, thirst).

• Vaptans (conivaptan IV, tolvaptan PO) for euvolemic hypoNa; BBW monitor Na.

NURSING

• Continuous assessment: vitals, I&O, weight, labs.

• Monitor infusion compatibility, IV site, elderly/peds higher sensitivity.

• Albumin risk hypervolemia → HF.

Chapter 24 – Heart Failure Drugs

KEY TERMS

• Positive inotrope ↑ contractility; chronotrope ↑ HR; dromotrope ↑ conduction.

CORE THERAPY (2017 AHA/ACC)

1. ACE I or ARB

2. β-blocker (metoprolol, carvedilol)

3. Loop diuretic for volume

4. Add aldosterone antagonist (spirono/eplerenone) as HF progresses.

5. Digoxin, hydralazine/isosorbide (esp. African-Amer.), ivabradine, ARNI (sacubitril/valsartan) as indicated.

ACE I

• Prevent Ang II & aldosterone; ↓ preload/afterload; cough, hyperK, angioedema; BBW fetal toxicity.

ARBs

• Valsartan etc.; ↓ SVR; no cough; BBW pregnancy.

ARNI

• Sacubitril/valsartan; Class I for HFrEF; SE: hypotension, hyperK, ↑ Cr.

β-BLOCKERS

• Cardioprotective – block SNS catecholamines; ↓ HR/contractility.

ALDOSTERONE ANTAGONISTS

• Spironolactone, eplerenone – ↓ remodeling; risk hyperK.

B-TYPE NATRIURETIC PEPTIDE

• Nesiritide IV acute decomp; not 1st line.

PHOSPHODIESTERASE INHIBITOR

• Milrinone IV inodilator; A/E dysrhythmia, hypotension.

DIGOXIN

• + inotrope/– chronotrope, narrow TI (0.5–2 ng/mL); ↑ tox with hypoK/Mg, ↓ renal.

• S/S tox: blurry yellow vision, bradyarrhythmia; antidote: digoxin immune Fab.

NURSING

• Baseline BNP, electrolytes, apical pulse (hold < 60), renal/LFT.

• Monitor weight, edema, lung sounds, I&O.

Chapter 25 – Antidysrhythmic

• Class I (Na⁺ block), II (β-block), III (K⁺ block e.g., amiodarone – BBW hepato-/pulmo-tox), IV (Ca²⁺ block).

• All prodysrhythmic; monitor ECG QT prolongation.

• Warfarin interaction esp. amiodarone (↑ INR); monitor.

Chapter 22 – Antihypertensives

• Classes: diuretics (1st line), adrenergics (α-2 agonist clonidine; α-1 blocker doxazosin; β-blockers; α/β labetalol), ACE I, ARB, CCB, vasodilators (hydralazine, minoxidil, nitroprusside), direct renin inhibitor (aliskiren).

• ACE/ARB less effective African-American monotherapy.

• Vasodilators rapid BP drop – monitor.

• BBW: ACE/ARB fetal toxicity; minoxidil, nitroprusside cyanide tox.

• Nursing: BP trends, orthostatic hypotension, abrupt withdrawal → rebound HTN.

Chapter 23 – Antianginal

• Nitrates (nitroglycerin, isosorbide): ↓ preload/afterload; A/E headache, reflex tachy; tolerance – nitrate-free interval 10–12 h.

• β-blockers: decrease demand.

• CCBs: vasodilate coronaries; amlodipine, diltiazem, verapamil.

• Ranolazine for chronic stable angina prolongs QT.

• Nursing: SL nitro q5 min × 3, store in dark, replace 3–6 mo; avoid PDE-5.

Chapter 27 – Antilipemics

STATINS (HMG-CoA RI)

• Atorva, rosuva, simva, prava, lova, fluva, pitava.

• ↓ LDL (30–50 %), modest ↑ HDL, ↓ TG; give PM; A/E myopathy → rhabdo, ↑ LFT.

BILE ACID SEQUESTRANTS

• Cholestyramine, colesevelam; bind BA in gut; GI issues, take other drugs 1 h before/4–6 h after.

NIACIN

• ↓ LDL/TG, ↑ HDL; flushing (pretreat ASA), hepatotoxic.

FIBRATES

• Gemfibrozil, fenofibrate – ↓ TG; ↑ warfarin, rhabdo with statins.

CHOLESTEROL ABSORPTION INHIBITOR

• Ezetimibe – ↓ LDL; often with statin.

PCSK-9 INHIBITORS

• Alirocumab, evolocumab SC q2–4 wks; huge LDL ↓.

Chapter 30 – Pituitary Drugs

• Cosyntropin (ACTH) diagnostic; Somatropin (GH) for deficiency, HIV wasting (risk hyperglycaemia, slipped epiphysis).

• Octreotide: GH antagonist; tx acromegaly, carcinoid crisis; monitor glucose, ECG.

• Vasopressin/desmopressin: DI, ACLS pulseless arrest (vaso), esophageal varices; BBW hyponatraemia.

• Nursing: baseline height/weight, BP, F&E, watch intranasal admin, rotate SQ sites.

Chapter 31 – Thyroid

• Levothyroxine synthetic T₄ – 1st line; long half-life 7 days; take AM empty stomach; narrow TI; watch for hyperthyroid Sx.

• Antithyroid: propylthiouracil (PTU), methimazole – inhibit iodination; A/E agranulocytosis, hepatotoxic; supportive until euthyroid.

• Radioiodine ¹³¹I ablation; β-blocker symptomatic.

Chapter 32 – Antidiabetic

INSULINS

• Rapid (lispro, aspart, glulisine, Afrezza inhaled), Short (regular IV), Intermediate (NPH), Long (glargine, detemir, degludec).

• Basal-bolus regimen preferred; U-500 caution high-alert.

ORAL/INJECTABLE AGENTS

• Biguanide: metformin (1st-line; CI eGFR<30; A/E GI, lactic acidosis).

• Sulfonylurea: glipizide etc. – ↑ insulin; risk hypo.

• Glinides: repaglinide – short meal-time.

• TZD: pioglitazone – PPAR-γ; risk HF, edema.

• α-glucosidase inhibitor: acarbose – flatulence, take with first bite.

• DPP-4 inhibitors (-gliptin): sitagliptin etc.; nasopharyngitis, pancreatitis.

• SGLT-2 inhibitors: canagliflozin etc.; ↓ renal glucose reabs; A/E GU infections, euglycemic ketoacidosis, amputations.

• GLP-1 agonists (inject): exenatide, liraglutide; weight-loss; risk thyroid C-cell tumor.

• Amylin analogue: pramlintide – inject with meals.

NURSING

• Assess BG, A1C, meal timing, renal; rotate sites.

• Treat hypo (< 50 mg/dL): PO glucose or glucagon IM/IV D50W.

Chapter 14 – Antiepileptics

• Goals: seizure control w/ minimal A/E; mono-therapy first; monitor serum levels.

• Classic agents: phenytoin, carbamazepine (BBW blood dyscrasia), valproic acid (BBW hepatotoxic, pancreatitis), phenobarbital.

• Newer: levetiracetam, lamotrigine (rash SJS), topiramate, gabapentin.

• Many are CYP inducers/inhibitors; ↓ OCP efficacy.

Chapter 15 – Antiparkinson

• Levodopa/carbidopa mainstay; wearing-off after 5–10 yr.

• COMT inhib: entacapone (brown urine), tolcapone (BBW liver failure).

• MAO-B inhib: selegiline, rasagiline (↑ tyramine crisis less risk).

• Dopamine agonists: pramipexole, ropinirole, rotigotine patch.

• Amantadine for dyskinesia (livedo reticularis).

• Anticholinergic: benztropine for tremor; avoid in elderly BPH/glaucoma.

Chapter 12 – CNS Depressants

• Benzodiazepines: diazepam, lorazepam, alprazolam; schedules IV; risk dependence (2020 BBW for abuse).

• Non-benzo hypnotics: zolpidem (sleep-walking), zaleplon, eszopiclone.

• Orexin antagonist: suvorexant (somnolence).

• Barbiturates: phenobarbital, pentobarbital – narrow TI, enzyme inducer; risk respiratory arrest.

• Muscle relaxants: baclofen, cyclobenzaprine, dantrolene; CNS depression.

Chapter 13 – CNS Stimulants

• ADHD: amphetamine, methylphenidate, lisdexamfetamine (prodrug) – Schedule II; A/E appetite loss, insomnia, ↑BP.

• Narcolepsy: modafinil, armodafinil.

• Anorexiants: phentermine, orlistat (GI fat block), lorcaserin; contraindicated CVD.

• Antimigraine triptans (5-HT₁B/1D): sumatriptan, rizatriptan; vasoconstrict; contraind CAD; new CGRP-mAbs (erenumab).

• Analeptics: caffeine, doxapram – stimulate medulla resp ctr; neonatal apnea.

Chapter 45 – Antineoplastics (Overview)

• Cell-cycle specific: Antimetabolites (methotrexate, 5-FU – palmar-plantar syndrome), Mitotic inhibitors (vincristine – fatal intrathecal), Taxanes (paclitaxel), Topoisomerase I (irinotecan – cholinergic diarrhea), Antineoplastic enzymes (asparaginase – pancreatitis).

• Non-specific: Alkylating, Anthracyclines, Platinum.

• Dose-limiting toxicities: myelosuppression, GI mucositis, alopecia.

• Cytoprotectants: allopurinol/rasburicase (TLS), dexrazoxane (cardio-protect), amifostine (renal).

• Nursing: ANC < 500 hold; antiemetics, extravasation protocols, infection precautions.

Chapter 35 – Male Health

• Testosterone (IM, transderm) – BBW thrombosis; contraind prostate cancer.

• 5-α-reductase inhibitors: finasteride, dutasteride – BPH, alopecia; women avoid handling; ↓ PSA 50 %.

• α-1 blockers: tamsulosin relieve BPH obstructive sx.

• PDE-5 inhibitors: sildenafil, tadalafil, vardenafil, avanafil – ED & PAH; contraind nitrates; A/E priapism, vision loss.

• Anabolic steroids (oxandrolone) Schedule III; risk liver cancer, infertility.

Chapter 34 – Female Health

ESTROGENS & PROGESTINS

• HRT individualized; contraind: estrogen-dependent cancer, thromboembolism, pregnancy, undx bleed.

• A/E: DVT/PE, stroke, breast CA; add progestin if uterus intact.

• SERMs: raloxifene (osteoporosis) – BBW VTE.

CONTRACEPTIVES

• Combined OCP mono-, bi-, triphasic; progestin-only, depot medroxyprogesterone (BBW bone loss), patch, ring.

• Antibiotics, anticonvulsants ↓ efficacy.

OSTEOPOROSIS THERAPY

• Bisphosphonates: alendronate – sit upright 30 min, esophagitis; atypical femur fx, ONJ.

• Calcitonin nasal, SERMs, denosumab (RANK-L mAb), teriparatide/abaloparatide (PTH analog 24 mo max), romosozumab (Evenity) – BBW MI/stroke.

FERTILITY DRUGS

• Clomiphene (SERM) induces ovulation; menotropins (FSH/LH); A/E multiple gestation, ovarian hyperstimulation syndrome.

UTERINE MODULATORS

• Oxytocin – induce labour, control PPH; watch uterine hyper-stimulation.

• Prostaglandins (dinoprostone, misoprostol) cervical ripening, abortion.

• Ergot (methylergonovine) post-partum hemorrhage.

• Tocolytics preterm labour: indomethacin (NSAID), nifedipine (CCB); BBW NSAID fetal effects.

NURSING ACROSS FEMALE DRUGS

• Contraindications (smoking > 35 yr, VTE, cancers).

• Baseline BP, pregnancy test.

• Bisphosphonate admin: AM empty stomach with 240 mL water.

• Oxytocin: continuous fetal, uterine monitoring.

These bullet-style notes consolidate key concepts, indications, mechanisms, adverse effects, contraindications, interactions, FDA/BBW alerts, and priority nursing implications for the chapters/pages supplied.