Pharmacology Prototype Drugs Review

PNS and SNS prototype drug review

Propranolol

Class/mechanism: Nonselective beta-blocker; inhibits sympathetic excitation

Primary clinical purpose: hypertension, dysrhythmias, heart failure, migraine prophalaxis,

Key adverse effects/safety alert: Dizziness, loss of energy, orthostatic hypotension, severe bradycardia, and bronchospasm.

Contraindications: Asthma and COPD patients

Emergency antidote/overdose treatment: Fluid expanders (normal saline) or vasopressors (dopamine/dobutamine) for hypotension

Bethanechol

Class/Mechanism: Muscarinic cholinergic agonist; parasympathomimetic; binds to ACH receptors to induce/mimic parasympathetic; CHOLINERGIC

Primary clinical purpose: Nonobstructive urinary retention and GI ulcers

Key adverse side effects/safety alert: Monitored for cholinergic crisis (SLUDGE)

Contraindication patients: in asthma, epilepsy, parkinsonism, peptic ulcer disease, bradycardia, GI/urinary obstruction, and pregnancy/lactation; NEVER give IM or IV.

Antidote/Overdose treatment: Atropine —> subQ or IV

Lorazepam

Class/mechanism: Benzodiazepine and GABA agonist; potentiates inhibitory GABA neurotransmission

Primary clinical purpose: Prescribed for anxiety, insomnia, and status epilepticus

Key adverse affects/safety alert: Drowsiness, sedation, dizziness, ataxia, and respiratory depression. IV route causes profound amnesia, weakness, and hypotension

Contraindication patients: Glaucoma, severe liver disease, and active suicidal ideation. ⚠ Black Box Warning: Mixing with alcohol or opioids causes fatal respiratory failure

Antidote/overdose treatment: Flumazenil

Zolpidem

Mechanism/class: Nonbenzodiazepine hypnotic; (Sedative-Hypnotic); preserves NREM stage 3 sleep

Primary clinical purpose: used for short-term insomnia management (7-10 days)

Key adverse effects/safety alerts: Daytime drowsiness, amnesia, confusion, sleepwalking, nocturnal eating, and hallucinations.

TAKE IMMEDIATELY BEFORE BED (7-27 MINS) WITHOUT FOOD

Contraindication patients: lactating women

Antidote/overdose treatment: Flumazenil

Escitalopram

Mechanism/class: SSRI; increases serotonin availability in the CNS

Primary clinical purpose: Generalized anxiety disorder (GAD), major depressive disorder (MDD), and panic disorder

Key adverse affects/safety alerts: Dizziness, nausea, insomnia, confusion, and seizures in overdose; Black Box Warning: Suicidal thinking/behavior risk in children, teens, and young adult

Contraindication patients: Do NOT combine with MAOIs or St. John's wort due to life-threatening Serotonin Syndrome. Requires a 2-3 week washout period

Antidote/overdose treatment: No specific antidote; general supportive care for seizures, confusion, and dysrhythmia

Sertraline

Mechanism/class: SSRI; blocks serotonin reuptake

Primary clinical purpose: Major depression, OCD, panic disorder, PTSD, PMDD, and social anxiety

Key adverse side effects/safety alerts: sexual dysfunction and weight gain; Black Box Warning: Suicidal risk in young populations

Contraindicated patients: those taking MAOIs. Do NOT combine with anticoagulants

Antidote/overdose treatment: Emergency medical attention and supportive care for tremors, seizures, and tachycardia

Imipramine

Mechanism/class: Tricyclic Antidepressant (TCA); blocks reuptake of norepinephrine and serotonin

Primary clinical purpose: Major depression, nocturnal enuresis (bed-wetting) in children, off-label for chronic pain

Key adverse side effects/safety alerts: Sedation, orthostatic hypotension, dysrhythmias, and anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation)

Contraindicated patients: severe liver and kidney disease; Black Box Warning: Suicidal risk in young adults

Antidote/overdose treatment: Stomach pump, activated charcoal, airway support, and cardiac rhythm monitoring

Phenelzine

Mechanism/class: Monoamine Oxidase Inhibitor (MAOI); irreversibly inhibits MAO enzyme to increase catecholamines

Primary clinical purpose: major depression and panic disorder

Key adverse side effects/safety alerts: Constipation, dry mouth, orthostatic hypotension, insomnia, and delirium. ⚠ Black Box Warning: Suicidal risk in young adults.

Contraindicated patients: Strict Tyramine Food Restriction: Ingesting tyramine (aged cheeses, wine, beer, pepperoni, salami, soy sauce) causes a life-threatening Hypertensive Crisis. Washout period of 2–3 weeks required

Antidote/overdose treatment: Slow IV diazepam for seizures, calcium channel blockers for severe hypertension, and IV fluids

Morphine

Mechanism/class: Opioid Receptor Agonist; binds to mu and kappa opioid receptors in the CNS

Primary clinical purpose: Moderate to severe acute/chronic pain, preanesthetic medication, dyspnea in pulmonary edema.

Key adverse side effects/safety alerts: Severe respiratory depression, sedation, constipation, nausea, euphoria, orthostatic hypotension, and physical dependence

IMPORTANT: Hold if respiratory rate is < 10 breaths/min

Contraindication patients: severe asthma, GI obstruction, and gallbladder disease. <br>⚠ Black Box Warning: Schedule II drug; monitor epidural for 24h; do not crush ER tablets

Antidote/overdose treatment: Naloxone (Narcan) IV

Naloxone

Mechanism/class: Pure Opioid Receptor Antagonist; competitively blocks mu and kappa receptor

Primary clinical purpose: Complete or partial reversal of acute opioid overdose, respiratory depression, and septic shock hypotension

Key adverse side effects/safety alerts: Rapid loss of analgesia, hyperventilation, tremors, elevated blood pressure, nausea/vomiting, and immediate opioid withdrawal

IMPORTANT: Administer for respiratory rate < 10 breaths/min

Contraindication patients: Ineffective against nonopioid respiratory depression

Antidote/overdose treatment: Oxygen, IV fluids, vasopressors, and supportive care for combined drug overdoses

Acetaminophen

Mechanism/class: Centrally Acting Nonopioid Analgesic & Antipyretic; acts at the level of the hypothalamus to cause vasodilation

Primary clinical purpose: Treatment of mild-to-moderate pain and fever reduction. (Has NO anti-inflammatory properties)

Key adverse side effects/safety alerts: Minimal side effects at therapeutic doses. Accidental overdose causes severe hepatic necrosis / liver failure

MAX PER DAY: 4000 MG/24 HRS

Contraindication patients: active liver disease or chronic alcoholism

Antidote/overdose treatment: Emergency liver protection protocol (acetylcysteine) and supportive care.

Phenylephrine (Neo-Synephrine)

Mechanism/class: Selective Alpha-1 Adrenergic Agonist; directly stimulates alpha-1 receptors to cause vasoconstriction and mydriasis

Primary clinical purpose: Nasal decongestant (topical), mydriatic for eye exams, and parenteral agent for acute hypotension in shock or spinal anesthesia

Key adverse side effects/safety alerts: Intranasal mucosal burning, rebound congestion, reflex bradycardia, CNS anxiety/tremors, and severe tissue necrosis with extravasation; Black Box Warning: Severe reactions or death with IV infusion

Contraindication patients: pancreatitis, hepatitis, Co-administration with MAOIs causes a hypertensive crisis

Antidote/overdose treatment: Phentolamine

Atropine

Mechanism/class: Muscarinic Cholinergic Receptor Blocker (Anticholinergic / Parasympatholytic); suppresses parasympathetic tone to induce a sympathetic state

Primary clinical purpose: increase heart rate for bradycardia patients, dilate pupils during eye exams, IBS

Key adverse side effects/safety alerts: Tachycardia, dry mouth, urinary retention, constipation, photophobia, decreased sweating (hyperthermia risk), and delirium/coma.

Contraindicated patients: cardiac in sufficiency (tachycardia); hypertension, glaucoma, acute hemorrhage

Antidote/overdose treatment: Physostigmine for ATROPINE POISONING

Methylphenidate (Ritalin, Concerta, Daytrana)

Mechanism/class: CNS Stimulant; activates the reticular activating system (RAS) by releasing norepinephrine and dopamine

Primary clinical purpose: Attention deficit/hyperactivity disorder (ADHD) and narcolepsy

Key adverse side effects/safety alerts: Nervousness, insomnia, irregular heartbeat, hypertension, weight loss, and liver toxicity. ⚠ Black Box Warning: Schedule II drug with high abuse potential; risk of sudden death or serious cardiovascular events

Contraindication patients: severe anxiety, psychosis, suicidal ideation, glaucoma, motor tics, or Tourette's.

Antidote/overdose treatment: No specific antidote; emergency medical attention and general supportive care for acute CNS overstimulation

Sumatriptan (Imitrex)

Mechanism/class: 5-HT (Serotonin) Receptor Agonist (Triptan); selectively constricts cranial intracranial arteries

Primary clinical purpose: Acute treatment to abort migraine attacks with or without aura

Key adverse side effects/safety alerts: Dizziness, drowsiness, warming/flushing sensations, severe systemic hypertension, dysrhythmias, and MI

MAX 2 DOSES/24 HRS

Contraindicated patients: recent MI, history of angina, uncontrolled hypertension, CAD, or severe renal/hepatic impairment

Antidote/overdose treatment: No specific antidote; supportive care for weakness, tremors, seizures, or respiratory distress

Aspirin (Acetylsalicylic Acid / ASA)

Mechanism/class: Salicylate NSAID; irreversible cyclooxygenase (COX-1 & COX-2) inhibitor providing antipyretic, analgesic, anti-inflammatory, and antiplatelet effects

Primary clinical purpose: Mild-to-moderate pain, fever, inflammatory conditions

Key adverse side effects/safety alerts: Gastric discomfort, peptic ulcers, and GI bleeding (black, tarry stools smelling like pennies). 🚨 Reye's Syndrome Alert: Strictly contraindicated in children/adolescents

Contraindication patients: anticoagulant therapy, Must be discontinued 1 week prior to elective surgery due to irreversible platelet inhibition

Antidote/overdose treatment: Stomach pump, activated charcoal, laxatives, and supportive care for tinnitus, dizziness, or seizures

Ibuprofen (Motrin, Advil)

Mechanism/class: Nonselective COX-1 & COX-2 Inhibitor NSAID; prevents prostaglandin formation to manage pain, fever, and inflammation

Primary clinical purpose: Relief of mild-to-moderate pain, fever reduction, and acute/chronic inflammatory joint conditions (arthritis)

Key adverse side effects/safety alerts: GI upset, peptic ulceration, fluid retention, and acute renal failure

Contraindication patients: active kidney disease

MUST BE TAKEN WITH FOOD OR MILK; MAX 3,200 MG/DAY

Antidote/overdose treatment: Gastric decontamination, activated charcoal, and general supportive medical care

Celecoxib (Celebrex)

Mechanism/class: Selective COX-2 Inhibitor NSAID (Prescription); targets COX-2 to block inflammatory prostaglandins while sparing stomach-protective COX-1

Primary clinical purpose: Acute pain, fever, and severe chronic joint inflammation (osteoarthritis and rheumatoid arthritis)

Key adverse side effects/safety alerts: Mild GI and cardiovascular thrombotic risk

MUST be taken with food. Cannot be combined with other NSAIDs

Contraindicated patients: sulfonamide allergies or post-surgery

Antidote/overdose treatment: Symptomatic and supportive emergency medical care