Opioid Analgesics · Anticonvulsants · Benzodiazepines · Antidepressants & Anxiolytics
Four CNS drug families, one study map: class (what family?) → action (what does it change?) → watch (safety & teaching). These are the drugs that show up over and over on NCLEX — learn the brand/generic pairs cold, then hang one mechanism and one trap on each.
📄 Simple Nursing original — opens in Drive →
Robo's 3-part study map for every drug on this page: CLASS → ACTION → WATCH.
| Class | Brand Name(s) | Generic Name |
|---|---|---|
| Opioid Analgesic | Demerol | Meperidine HCl |
| Dilaudid | Hydromorphone | |
| Duragesic, Sublimaze | Fentanyl | |
| Morphine Sulfate | Morphine Sulfate | |
| Vicodin, Norco | Hydrocodone | |
| Anti- convulsant | Dilantin | Phenytoin |
| Neurontin | Gabapentin | |
| Tegretol | Carbamazepine | |
| Depakote | Valproic Acid | |
| Benzo- diazepine | Xanax | Alprazolam |
| Valium | Diazepam | |
| Ativan | Lorazepam | |
| Versed | Midazolam | |
| SSRI | Celexa | Citalopram |
| Lexapro | Escitalopram Oxalate | |
| Paxil | Paroxetine | |
| Prozac | Fluoxetine | |
| Zoloft | Sertraline | |
| SNRI | Effexor | Venlafaxine |
| TCA | Elavil | Amitriptyline |
| Anxiolytic | Buspar | Buspirone HCl |
One card per class: what it is, how it works, the one nursing point that matters most, and the trap NCLEX loves to hide.
Mechanism: ↑ pain threshold by altering pain perception in the CNS (bind mu-opioid receptors).
⭐ Key nursing point: Assess respiratory rate and sedation level before every dose — hold and notify the provider for significant respiratory depression or oversedation. Pair with a scheduled bowel regimen (opioids slow peristalsis → constipation is universal, not occasional).
Trap 1: Meperidine (Demerol) builds up a toxic metabolite, normeperidine, especially with repeated dosing or renal impairment — can cause CNS excitation and seizures. It is not a first-line choice for ongoing/chronic pain.
Trap 2: Antidote = naloxone (Narcan). Reversal is short-acting compared to many opioids — the patient can re-sedate after the naloxone wears off, so keep monitoring.
Mechanism: ↑ the interval between seizures / raise the seizure threshold so neurons fire less easily.
⭐ Key nursing point: Monitor blood levels for phenytoin (Dilantin), carbamazepine (Tegretol), and valproic acid (Depakote) — narrow therapeutic windows. Gabapentin (Neurontin) is also frequently prescribed off-label for chronic neuropathic pain.
Mechanism: enhance/facilitate GABA, the brain's main inhibitory neurotransmitter — opens the chloride channel more often, calming neuron firing.
⭐ Key nursing point: monitor sedation, respiratory status, and fall risk. Versed (midazolam) is commonly used for short procedural sedation. Never discontinue abruptly after regular use — withdrawal can include seizures.
Mechanism: inhibit serotonin reuptake in the CNS, leaving more serotonin available at the synapse.
⭐ Key nursing point: full antidepressant effect takes about 2–4 weeks — teach patients not to expect immediate relief and not to stop early because "it isn't working yet." Watch closely for worsening mood or suicidal ideation early in treatment, especially in adolescents/young adults.
Mechanism: Effexor (SNRI) blocks reuptake of both norepinephrine and serotonin at nerve endings. Elavil (TCA, older class) works similarly but also blocks histamine/cholinergic/alpha receptors, giving it more side effects.
⭐ Key nursing point: TCAs are cardiotoxic in overdose (widened QRS, dysrhythmias) — narrow therapeutic index, teach strict adherence and safe storage, especially with a depressed or at-risk patient.
Mechanism: exact mechanism not fully defined; thought to act by changing serotonin activity in certain brain regions.
⭐ Key nursing point: Buspar is not a PRN anxiety drug — it takes about 2–4 weeks of scheduled dosing to reach full effect, has minimal sedation, and carries no significant abuse/dependence potential, unlike the benzodiazepines above.
What to say at the bedside, and the one table that keeps benzos and SSRIs from blurring together.
| Benzodiazepine | SSRI |
|---|---|
| Onset: fast — can relieve acute anxiety same-day | Onset: slow — 2–4 weeks for full effect |
| Mechanism: enhances GABA (inhibitory) | Mechanism: blocks serotonin reuptake |
| Dependence/abuse potential: higher, taper to stop | Dependence/abuse potential: low, but taper to avoid discontinuation syndrome |
| Antidote available: flumazenil | No specific antidote — treat serotonin syndrome supportively |