Pharm GI and CNS/Psych Meds

phenytoin

Class: Anticonvulsant

Use: Seizures (unconscious muscle contractions)

Action: Binds to sodium channels on nerve membranes and makes them less active.

Adverse Reactions: Gum hyperplasia, abdominal discomfort, dysthymia.

Nursing Implications: Many adverse drug interactions, birth defects during pregnancy.

Teaching: Most side effects are worse when starting and can improve.

phenobarbital

Class: Anticonvulsant

Use: Seizures (unconscious muscle contractions), sleep, anxiety.

Action: Raises the threshold for a seizure by boosting GABA resulting in CNS depression.

High Alert: Class IV

Adverse Reactions: Drowsiness, ataxia (impaired coordination), blurred vision, dysthymia.

Nursing Implications: many adverse drug interactions. Birth defects during pregnancy.

Teaching: Most side effects are worse when starting and can improve. Risk of falling and cognitive impairment.

Lacosamide

Class: Anticonvulsant

Use: Seizures (unconscious muscle contractions)

Action: Acts at sodium channels to stabilize, neurons and prevent repetitive firing.

Adverse Reactions: Euphoria (leads to dependence), orthostatic hypotension, syncope, headaches, dizziness, blurred vision, double, vision, fatigue, nausea, and ataxia.

carbidopa / levodopa (given together)

Class: Dopamine Agonist

Use: Parkinson’s Disease

Action: Carbidopa helps more Levodopa into the brain. Levodopa converts to dopamine. Increased dopamine to reduce muscle tremors, and rigidity, and improve mobility, coordination, and performance.

Adverse Reactions: Hypoglycemia, Dyskinesia (involuntary dance-like movement), postural hypotension, headache, GI disturbances, insomnia, strange dreams, impulse control, and confusion.

Nursing Implications: Combining with dopamine agonists can cause severe hypotension. Combining with MAO inhibitors can cause hypertension.

Teaching: Take 30-60 min before meals to help absorption. Don’t crush extended release tablets, which are not recommended for starting treatment.

donepezil

Class: Cholinesterase Inhibitor

Use: Alzheimer’s

Action: Binds to acetylcholinesterase to stop it from breaking down ACH too fast. ACH helps with memory and stuff.

Becomes less effective with time, as fewer brain cells remain to make ACH.

Adverse Reactions: Hallucinations, dysrhythmias, GI bleeding, infection, difficulty urinating, incontinence.

Nursing Implications: Don’t give with other drugs that can prolong the QT interval on the ECG.

Teaching: Take at bedtime to minimize side effects.

memantine

Class: NMDA Blocker

Use: Alzheimer’s

Action: Prevents excess calcium from entering the brain, reducing or slowing damage to the neurons.

Adverse Reactions: Dysrhythmias, headaches, dizziness, and constipation.

Nursing Implications: Don’t give with other drugs that can prolong the QT interval on the ECG.

Teaching: Take at bedtime.

lorazepam

Class: Antianxiety (Benzodiazepines)

Use: Anxiety, alcohol withdrawal, preoperatively, muscle spasm relief.

Action: Depresses the CNS by binding to benzodiazepine receptors.

Adverse Reactions: Dependence, memory loss, drowsiness

Nursing Implications: Use for shortest time possible due to dependence.

Contraindication: Liver disease.

Teaching: Birth defects when pregnant. Don’t take with alcohol or other depressants.

sertraline

Class: Antidepressant (SSRIs)

Use: Depression, PTSD, OCD, general anxiety disorder, premenstrual dysphoric disorder.

Action: Inhibits neuronal uptake of serotonin, thus increasing action of serotonin as a mood stabilizer.

Adverse Reactions: Risk of suicide, bleeding, hyponatremia (low blood sodium), bone fractures, drowsiness, insomnia, dry mouth, decreased appetite, sweating, constipation, decreased sex drive and ability to orgasm.

Nursing Implications: other drugs can cause serotonin syndrome (life threatening).

Teaching: Takes weeks to notice an effect. Don’t stop abruptly.

haloperidol

Class: Antipsychotic

Use: Severe mental illness, may be combined with major tranquilizers.

Action: Block dopamine in the brain.

Adverse Reactions: Pseudo-Parkinsonism, acute dystonia, akathisia, neuroleptic malignant syndrome and tardive dyskinesia. 10% of patients experience these symptoms.

Nursing Implications: Assess level of consciousness, agitation, hallucinations. Drug interactions with acetaminophen diuretics, calcium channel blockers, anti-diabetics.

Teaching: may take weeks to notice effect. Stay hydrated, report unusual movements or spasms.

Pseudoparkinsonism, Acute dystonia, Akathisia, Tardive dyskinesia

lithium carbonate

Class: Antimanic

Use: Mood-stabilizer for bipolar disorder during the manic phase.

Action: Alters sodium transport at nerve endings and enhances uptake of serotonin and norepinephrine by the cells.

Adverse Reactions: Hypothyroidism, renal failure, diabetes insipidus, weight gain, increased thirst and urine output, dry skin.

Nursing Implications: Amount needed for an effective dose is close to causing toxic effects (range: 0.5-1.5). Interacts with diuretics, antidepressants, antipsychotics, NSAIDS.

Teaching: Takes weeks to notice effect. No alcohol or other depressants. Check lithium levels every 6-8 weeks.

midazolam

Class: Sedative-hypnotic (benzodiazepines)

Use: Preoperative sedation, amnesia, sedation during outpatient procedures.

Routes: IV (Sedative effect), Oral (antianxiety)

Action: Depresses the CNS and boosts GABA.

Adverse Reactions: Apnea (no breathing), drowsiness, headache.

Nursing Implications: Asses respiratory status prior to administering.

Teaching: Amnesia effect after procedure, avoid driving and alcohol for 24 hours.

calcium carbonate

Maalox, Tums

Class: Antacid

Use: Peptic ulcers, gastroesophageal reflux disease (GERD), heart burn, calcium supplement.

Action: Neutralizes hydrochloric acid (HCI) in the stomach, increasing gastric pH and reducing gastric irritation.

Adverse Reactions: Hypercalcemia, hypercalciuria, hypermagnesia, bradycardia, dysrhythmias, anorexia, diarrhea, constipation.

Nursing Implications: Oral route. Give 2 hours before or after other meds (absorption interference).

Contraindications: Hypercalcemia, kidney stones.

Teaching: Report tingling, muscle spasms.

famotidine

Pepcid

Class: Histamine H2-receptor antagonist

Use: Neutralizes acid and promotes healing of ulcers, GERD.

Action: Blocks histamine from H2-receptors to prevent stimulation of the secretory cells. Lowers acidity during the day and night and after consuming things like caffeine.

Adverse Reactions: Dizziness, headache, somnolence, diarrhea, hematologic changes, muscle pain.

Nursing Implications: Caution around those sensitive: pregnant, breastfeeding, children, geriatric. Patients with decreased renal function.

Teaching: Avoid hazardous activities, alcohol.

omeprazole

Losec

Class: Proton-pump inhibitor (PPI)

Use: Peptic ulcers, GERD, stress ulcers

Action: Attach to proton-pump, irreversibly stopping the acid secretary pump, stopping acid production.

Adverse Reactions: headache, diarrhea, abdominal pain, nausea, rarely rash, dizziness.

Nursing Implications: Precautions: pregnancy, breastfeeding, children, Asian, Black, hepatic disease.

Teaching: Take before food. Avoid alcohol (GI irritation). Report severe diarrhea, black tarry stools.

sucralfate

Carafate

Class: Cytoprotective

Use: Peptic ulcers

Action: Protects the lining of the stomach from further damage from acids.

Adverse Reactions: Dry mouth, constipation, bezoar.

Nursing Implications: Precautions: pregnancy breast-feeding, children, renal failure, hypoglycemia.

Teaching: Take on an empty stomach 1 hour before meals and at bedtime. Take 2 hrs before or after other meds. Take full course.

metoclopramide

Class: Promotility

Use: Post-op or chemotherapy induced nausea and vomiting, diabetic gastroparesis, and GERD.

Action: Move contents more quickly through the GI tract.

Contraindication: Levodopa/carbidopa

Adverse Effects: Drowsiness, restlessness, visual impairment, urinary retention, insomnia, depression, suicidal ideation.

Nursing Implications: Monitor mood, orthostatic hypotension.

Teaching: Don’t drink alcohol or operate heavy equipment.

loperamide

Class: Antidiarrheal

Use: Nonspecific diarrhea or diarrhea caused by antibiotics.

Action: Reduce fluid in stool, decrease peristalsis and motility of intestinal tract.

Adverse Reactions: Drowsiness, dizziness, and constipation.

Nursing Implications: Precautions: pregnancy breast-feeding, children under 2yrs, hepatic disease, gastroenteritis, toxic megacolon, geriatric.

Teaching: If diarrhea lasts more than 48 hours, seek further evaluation.

psyllium

Class: Bulk-forming agent

Use: Constipation

Action: Absorbs water and expands, increasing the bulk and moisture content of the stool. Peristalsis increases and absorbed water softens the stool.

Adverse Reactions: GI upset, electrolyte disturbances, reduce effectiveness of antibiotics, anticoagulant, digitalis, and salicylates.

Nursing Implications: Takes 12 hours to 3 days to work.

Teaching: Increase activity level (peristalsis), fluids, for short term use.

docusate

Class: Stool softener

Use: Constipation, to avoid straining post-op.

Action: Allows fats and water to soften the stool.

Adverse Reactions: GI upset, electrolyte disturbances, reduce effectiveness of antibiotics, anticoagulant, digitalis, and salicylates.

Nursing Implications: Works in 1-3 days.

Teaching: Increase activity level (peristalsis), fluids, for short term use.

lactulose

Class: Saline laxative

Use: Constipation, to clean out bowels before colonoscopies or surgeries, examinations.

Reduces ammonia levels in liver failure patients.

Action: Osmotic effect draws water into bowel, increasing size and softening stool, promoting peristalsis.

Adverse Reactions: GI upset, electrolyte disturbances, reduce effectiveness of antibiotics, anticoagulant, digitalis, and salicylates.

Nursing Implications: Works quickly in 30 minutes to 6 hours.

Teaching: Increase activity level (peristalsis), fluids, for short term use.

magnesium hydroxide

Class: Saline laxative

Use: Constipation, to clean out bowels before colonoscopies, surgery, examinations.

Action: Osmotic effect draws water into bowel, increasing size and softening stool, promoting peristalsis.

Adverse Reactions: GI upset, electrolyte disturbances, reduce effectiveness of antibiotics, anticoagulant, digitalis, and salicylates.

Nursing Implications: Precautions: pregnancy, renal disease, cardiac disease.

Teaching: Increase activity level (peristalsis), fluids, for short term use. Discontinue if cramping, rectal bleeding, or vomiting.

bisacodyl

Class: Stimulant or irritant laxative

Use: Quick constipation relief from poor diet, being in bed a long time, or other meds.

Action: Increase peristalsis by stimulating intestine nerves, irritating the intestine mucosa, and increase water and electrolyte secretion.

Adverse Reactions: GI upset, electrolyte disturbances, reduce effectiveness of antibiotics, anticoagulant, digitalis, and salicylates.

Nursing Implications: Works in 6-8 hours.

Teaching: Increase activity level (peristalsis), fluids, for short term use.

ondansetron

Zofran

Class: Antiemetic

Use: Nausea, vomiting—especially associated with chemotherapy and post-op.

Action: Blocks serotonin 5-HT peripherally, centrally, and in the small intestine.

Adverse Reactions: Headache, dizziness, drowsiness, diarrhea, constipation, abdominal pain, dry mouth, rash.

Nursing Implications: Precautions: pregnancy, breastfeeding, children, geriatric.

Teaching:

Antacids (class)

• Neutralize existing hydrochloric acid (HCI) in the stomach.

• Increase gastric pH. (lowers acidity)

• For temporary relief only.

• Doesn’t prevent future attacks.

• Typically contain calcium, magnesium, and/or aluminum.

• Used as adjunct therapy, not primary treatment.

Histamine H2-Receptor Blockers (class)

• Decrease gastric acid secretion by blocking histamine binding to H2 receptors on parietal cells in the stomach.

• Reduce basil, gastric acid production. (baseline acid throughout the day)

• Decrease day and nighttime gastric acid.

• Reduce meal stimulated acid secretion.

• Decrease acid released in response to substances like caffeine.

• Can be used intravenously before or during major surgery to prevent stress ulcers.

Proton-Pump Inhibitors (PPIs) (class)

• Stop the acid secretory pump in the gastric parietal cell membrane.

• Block the proton pump directly, preventing acid secretion into the stomach.

• Provide the most complete acid suppression of all drug classes.

• Used in critically ill patients to prevent stress ulcers.

• Often used with other drugs to treat H. pylori infection.

Cytoprotective Drugs (class)

Protect the stomach lining and prevent further damage.

Allow existing ulcers to healed by providing physical protection.

Laxatives (class)

• Promote bowel movements and relieve constipation.

• increase G.I. motility and facilitate stool passage through various actions:

Bulk-forming by absorbing water, softening stool by allowing water to enter, lubricants create barrier preventing fluid reabsorption, stimulants increase peristalsis (muscle constriction and relaxation).

Anticholinergics and Antispasmodics (class)

• Reduce diarrhea and associated symptoms.

• For peptic ulcer, pylorospasm, biliary colic, hypermotility, acute pancreatitis.

• Block acetylcholine from binding to receptors in nerve cells of the parasympathetic system.

• decrease G.I. tract spasm and intestinal, motility. Reduce acid production, slow gastric emptying, reduce gastric motility, and associated pain.

• Rarely used alone.

Adverse reactions: high dosages cause CNS issues like agitation, confusion, delirium, and seizures.

Implications: Don’t stop taking suddenly. Don’t use during infectious diarrhea (needs to clear out). Don’t give to patients with GI obstructions, enlarged prostate, or glaucoma (worsens them).

Bulk-Forming Laxatives

Action: Absorb water in the G.I. tract, expanding the stool, increasing bulk. The increased bulk stimulates peristalsis, and the absorbed water softens the stool.

Use: Treats and prevents constipation, manages irritable bowel syndrome, and diverticulosis.

• Onset of 12 hours to 3 days.

Adverse Effects: G.I. upset. Risk of esophageal obstruction if not taken with enough water at least 8 to 12 ounces swelling of throat or choking. Hypersensitivity reactions from inhaling psyllium dust, including bronchospasm and anaphylaxis.

Stool Softeners

Action: Reduce surface tension of stool, so water and lipids can enter and soften the feces, making it easier to pass.

Uses: After surgery or patients who should avoid straining.

Onset: 1-3 days.

Adverse Effects: GI upset, severe allergic reactions possible.

Lubricant laxatives

Action: Create a barrier between feces and colon wall that prevents absorption of fecal fluid, softening the stool. The lubricant eases passage of feces through the intestine.

Use: When straining should be avoided. Prevent pain and decreased risk of tearing hemorrhoids, or anal fissures.

Onset: 6-8 hours.

Adverse Effects: GI upset, decreased absorption of nutrients and fat-soluble vitamins, lipid pneumonia from inhalation.

Osmotic (saline) laxatives

Action: Produce osmotic effect, drawing water into the intestinal lumen. Increased fluid softens stool and increases volume, stimulating peristalsis.

Use: Cleanse bowel for colonoscopy, x-ray, or GI surgery. Lactulose reduces ammonia levels in liver failure patients.

Onset: 1-3 hours

Adverse Effects: GI upset, fluid and electrolyte disturbance with daily use or in patients with renal/cardiac impairment.

Stimulant (Irritant) Laxatives

Action: Stimulates nerves in colon to increase peristalsis.

Uses: Acute constipation from prolonged bedrest, poor diet, or drug-induced.

Onset: 6-12 hours.

Adverse Effects: GI upset, muscle weakness (excessive use), dermatitis, pruritus, alkalosis, electrolyte imbalance (excessive use).

Cannabinoids

Action: Forms of THC bind to cannabinoid receptors in the chemoreceptor trigger zone, preventing serotonin 5–HT3 from binding.

Use: Reduces nausea and vomiting.

Adverse Effects: Feeling “high”, dizziness, anxiety, insomnia, difficulty concentrating, confusion, sedation, seizure-like activity.

Contraindication: Acute psychosis or unstable mental illness.

Teaching: Avoid alcohol sedatives, or CNS depressants. Take first dose 30 minutes before meal—later doses can be taken with food.