Medications Used in Specific Situations Flashcards
General Information: Antidepressants
- It may take 4-8 weeks for drug to achieve desired effect
- Medication discontinuation must be gradual to prevent withdrawal symptoms
Fluoxetine
SSRI MOA: - Selectively blocks reuptake of serotonin in the synaptic space, thereby intensifying the effects of serotonin and produces CNS excitation Indications: - Major depression - Bipolar disorder - Panic disorder - OCD Adverse Effects: - Weight gain - Sexual dysfunction - Serotonin syndrome: begins 2-72 hours after treatment following s/s: confusion, agitation, disorientation, anxiety, poor concentration. Resolves spontaneously when medication withdrawn Nursing Considerations: - Do not co-administer with MAOI's due to increased risk of serotonin syndrome - Monitor for serotonin syndrome!
Venlafaxine
SNRI MOA: Blocks NE and serotonin reuptake Indications: - Major depression - GAD - Social anxiety disorder Adverse Effects: - N/V - Headache - HTN - Nervousness - Anorexia Nursing Considerations: - Sudden stopping of medication causes intense withdrawal syndrome! - Slowly taper off over 2 weeks
Imipramine
TCA - 2nd line of tx
MOA: blocks neuronal reuptake of 2 monoamine NTs: norepinephrine & serotonin
Indications:
- Depression
- Bipolar Disorder
- Fibromyalgia Syndrome
Adverse Effects:
- CARDIAC TOXICITY (VF, VT, dysrhythmia)
- Sedation
- Orthostatic Hypotension
- Anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation, tachycardia, photophobia)
- Increased risk of suicide (give only 1 week supply)
- TCA overdose can be lethal! Treated with gastric lavage
Nursing Considerations:
- Do not administer if patient is taking MAOIs; can cause severe HTN (increased adrenergic stimulation)!
- If 8x therapeutic dose administered, treat with gastric lavage.
- Once a day dose due to prolonged half-life
Phenelzine
MAOI - 2nd or 3rd line of tx MOA: block monoamine oxidase in the brain, increasing the amount of NE, dopamine, serotonin, and tyramine available for transmission of impulses and relieves depression Indications: - Depression - Bulimia nervosa - Panic disorder - PTSD - OCD Adverse Effects: - HTN crisis is greatest concern!; triggered by NE release which gives a massive vasoconstrictive effect when foods containing tyramine are consumed (beef liver, ripe cheeses, yeast products, Chianti wine, etc.)
Bupropion
Atypical Antidepressant
MOA: blockade of dopamine and/or NE reuptake. Stimulant like amphetamine and suppresses appetite.
Indications:
- Major depression
- Seasonal Affective Disorder (SAD)
- Smoking cessation aid (marketed as Zyban/Bupropan)
- Unlabeled for ADHD mgmt
Adverse Effects:
- Generally well-tolerated
- Seizure risk of greatest concern
- agitation, tremor, tachycardia, dizziness, blurred vision, weight loss most common
Bipolar Disorder Treatment
Mood stabilizers:
- Relieve symptoms during manic/depressive episodes and prevents recurrence.
Antipsychotics:
- Control symptoms during severe manic episodes even if absent (haloperidol, olanzapine, risperidone)
Antidepressants:
- Often combined with mood stabilizer; limited research available on antidepressants in bipolar disorder (bupropion, venlafaxine, fluoxetine, sertraline)
Acute therapy:
- Lithium and valproate for manic episodes
- Lithium and valproate, possibly antidepressants if mood stabilizers inadequate for mild depressive episodes
Long-term preventative treatment:
- Mood stabilizer to prevent recurrence of mania and depression; lithium/valproate + antipsychotic
Lithium
Mood stabilizer
MOA: unknown; theories include altering glutamate uptake & release, blocking binding of serotonin to receptors, and neuroprotective, neurotrophic - can show a decrease in neuronal atrophy and/or an increase in neuronal growth.
Indications:
- DOC for treating and controlling acute manic episodes in patients with bipolar disorder (BPD)
- Long-term prophylaxis against recurrence of mania or depression
Adverse Effects:
- Excessive lithium levels (>1.5 mEq/L)
Therapeutic Range AE
- GI effects
- Tremors
- Polyuria
- Renal toxicity
- Goiter and hypothyroidism
- Teratogenesis
Nursing Considerations:
- Monitor lithium levels every 2-3 days at initiation of tx, then every 3-6 months.
- Lithium is most effective between 0.8-1 mEq/L but should always be kept below 1.5 mEq/L!
Phenytoin
Traditional Anti-epileptic drug (AED)
MOA: decreases Na+ influx and suppresses neuronal action potentials
Indications:
- Most widely used AED
- Controls partial (focal) and generalized tonic-clonic (grand mal) seizures
- Used post-neurosurgery to prevent/control seizures
- Off-label uses: antiarrhythmic, used for severe pre-eclampsia
Adverse Effects:
- Gingival hyperplasia
- Purple glove syndrome (SJS/TENS)
- CNS effects (nystagmus, ataxia, dysarthria, slurred speech, mental confusion, headache, insomnia, etc.)
- Hirsutism
- Increased glucose levels
Teratogenic effects
Nursing Considerations:
- Decreases effects of warfarin, oral contraceptives, etc.
- Diazepam, isoniazid, cimetidine, and EtOH can increase phenytoin levels
- Check phenytoin levels in 5-7 days if dose adjustment required
- Narrow therapeutic range
- Admin with food
- Caution in patients with hypersensitivity, bradycardia, heart block, and pregnancy (cat. D)
Ethosuximide
AED
MOA: decreases Ca+ influx; suppresses neurons in the thalamus that are responsible for generating absence seizures
Indications:
- DOC for absence seizures (petit mal)
Adverse Effects:
- Drowsiness, dizziness, headache, lethargy, nausea/vomiting
Nursing Considerations:
- Maintain therapeutic range (40-100 mcg/mL)
- Monitor drug levels at the start of tx and when changing dosage
- Taper dose gradually
- Caution in patients with hypersensitivity, severe liver or kidney disease, pregnancy (cat. C), suicidal ideation
Valproic Acid
MOA: Suppression of high-frequency neuronal firing through blockage of sodium channels; also blocks Ca+ influx through T-type Ca+ channels; also may augment the inhibitory influence of GABA
Indications:
- 1st line drug for all partial and generalized seizures, BPD, migraine prophylaxis
Adverse Effects:
- Generally well tolerated
- Rash, weight gain, hair loss, blood dyscrasias
- Minimal sedation
- Cognitive impairment
- N/V, indigestion
- Hepatotoxicity/pancreatitis
- Teratogenicity
Nursing Considerations:
- Higher risk of hepatotoxicity in patients younger than 2 years receiving multi-drug therapy; monitor liver function at baseline
- If GI effects, give with food or use enteric coated product
- Do not combine with topiramate; may cause hyperammonemia (vomiting, lethargy, altered LOC/cognitive function); discontinue if occurs
Spasticity v. Muscle Spasm
- Spasticity involves muscle stiffness related to CNS disorders such as multiple sclerosis, cerebral palsy, traumatic spinal cord lesions, and Parkinson disease.
- Muscle spasm is an involuntary muscle or muscle group contraction caused by epilepsy, hypocalcemia, and localized muscle trauma. It is often painful and limits movement!
Baclofen
MOA: acts within the spinal cord to suppress hyperactive reflexes involved in the regulation of muscle movement; no direct effect on muscle strength; also a CNS depressant
Indications:
- MS
- Some spinal cord injuries
- Does not relieve Parkinson, cerebral palsy, or stroke related spasticity
Adverse Effects:
- CNS depression common (drowsiness, dizziness, weakness, fatigue)
- Abrupt withdrawal can result in visual hallucinations, paranoid ideations and seizures; taper off slowly
- Overdose possible, resulting in coma/respiratory depression
Nursing Considerations:
- Monitor neuronal status, especially if on other CNS depressants
- Monitor urinary output, especially in those with BPH and/or on anticholinergics
Dantrolene
MOA: Acts directly on skeletal muscles, suppressing Ca+ release to decrease muscle contraction
Indications:
- Decrease spasticity associated with MS, cerebral palsy, and spinal cord injuries
- Malignant hyperthermia often from succinylcholine
Adverse Effects:
- Hepatotoxicity
Nursing Considerations:
- Monitor LFTs
Cyclobenzaprine
MOA: muscle relaxant that acts on the brainstem to reduce tonic motor activity to relieve acute muscle spasm
Indications:
- Muscle spasm only
Adverse Effects:
- CSN depression (drowsiness, dizziness, fatigue)
- Possible anticholinergic effects (dry mouth, blurred vision, urinary retention, etc.)
- Dysrhythmias
- Serotonin syndrome if given with antidepressants (SSRI, SNRI, TCA, etc.)
Nursing Considerations:
- Pre- and post-administration assessment of pain, spasm, ROM, and dexterity
- Avoid concurrent CNS depressant use
- Monitor and educate on anticholinergic effects
- Analgesics such as NSAIDs and acetaminophen may be co-administered for pain relief
