Psychopharm Flashcards
What are HAM side effects?
What drugs cause HAM side effects?
Antihistamine (sedation, weight gain)
Antiadrenergic (orthostatic hypotension, cardiac abnormalities, sexual dysfunction)
Antimuscarinic (dry mouth, blurred vision, urinary retention, constipation, exacerbation of neurocognitive disorders [eg dementia], precipitation of narrow-angle glaucoma)
Found in TCAs and low-potency antipsychotics (eg chlorpromazine [thorazine], thioridazine [mellaril])
Characteristics of serotonin syndrome
Confusion, flushing, diaphoresis, tremor, myoclonic jerks, hyperthermia, hypertonicity, rhabdomyolysis, renal failure, death
- Occurs when there is too much serotonin, classically when SSRIs and MAOIs are combined.
- As this combo is rarely seen in practice anymore, serotonin syndrome is more commonly seen when a patient is prescribed multiple medications with serotonergic activity (eg SSRIs/SNRIs, trazodone, Tramadol, triptans, dextromethorphan, St. Johns wort, ondansetron)
- Tx: stop meds, supportive care
Hypertensive crisis
Caused by buildup of stored catecholamines, triggered by combination of MAOIs with tyramine-rich foods (eg red wine, cheese, chicken liver, cured meats) or with sympathomimetics.
Extrapyramidal side effects
Parkinsonism - masklike face, cogwheel rigidity, bradykinesia, pill-rolling tremor
Akathisia - restlessness, need to move, agitation
Dystonia - sustained, painful contractions of muscles of neck, tongue, eyes, diaphragm
- Occur more frequently with high-potency, typical (first gen) antipsychotics (eg Haldol, prolixin, stelaine, orap), but can be seen with atypical
- Reversible
- occur within hours to days
In rare cases, can be life-threatening (eg dystonia of diaphragm)
Hyperprolactinemia
Occurs with high-potency, typical first gen antipsychotics and risperidone.
Tardive dyskinesia
Choreoatetoid muscle movements, usually of mouth and tongue (can affect extremities as well)
- Occurs after years of antipsychotic use (more likely with high-potency, first-generation)
- Usually irreversible
Neuroleptic malignant syndrome
Mental status changes, fever, tachycardia, HTN, tremor, elevated creatine phosphokinase (CPK), “lead pipe” rigidity
- Can be caused by any antipsychotic after short or long time (increased with high-potency, typical antipsychotics)
- Medical emergency with up to 20% mortality rate
CYP450 inducers
Tobacco (1A2)
Carbamazepine (1A2, 2C9, 3A4)
Barbiturates (2C9)
St. John’s wort (2C19, 3A4)
CYP450 inhibitors
Fluvoxamine (1A2, 2C19, 3A4) Fluoxetine (2C19, 2C9, 2D6) Paroxetine (2D6) Duloxetine (2D6) Sertraline (2D6)
List of SSRIs
Fluoxetine (Prozac) Sertraline (Zoloft) Paroxetine (Paxil) Fluvoxamine (Luvox) Citalopram (Celexa) Escitalopram (Lexapro)
Fluoxetine (Prozac)
SSRI
- longest half life, with active metabolites
- no need to taper
- safe in pregnancy, approved for use in children and adolescents
- common side effects: insomnia, anxiety, sexual dysfunction)
- can elevate levels of antipsychotics, leading to increased effects
Sertraline (Zoloft)
SSRI
- higher risk for GI disturbances
- very few drug interactions
- other common side effects: insomnia, anxiety, sexual dysfunction
Paroxetine (Paxil)
SSRI
- potent inhibitor of CYP26, which can lead to several drug-drug interactions
- common side effects: anticholinergic effects eg sedation, constipation, weight gain) and sexual dysfunction
- short half-life leading wo withdrawal phenomena if not taken consistently
Fluvoxamine (Luvox)
SSRI
- Currently approved only for use in OCD
- Common side effects: nausea and vomiting
- Multiple drug interactions due to CYP inhibition
Citalopram (Celexa)
SSRI
- Fewest drug-drug interactions
- Dose-dependent QTc prolongation
Escitalopram (Lexapro)
SSRI
- Levo-enantiomer of citalopram; similar efficacy, possibly fewer side effects
- Dose dependent QTc prolongation
How to address the sexual side effects of SSRIs
Sexual side effects of SSRIs can be treated by either reducing the dose (if clinically appropriate), changing to a non-SSRI antidepressant, augmenting the regimen with bupropion, or, in men, by adding meds like sildenafil
SSRI most associated with weight gain?
Most weight-neutral SSRIs?
weight gain: Paxil
weight neutral: fluoxetine and sertraline
Side effects of SSRIs
Common, resolving within a few days:
- GI disturbance (nausea and diarrhea; giving with food can help)
- Insomnia; also vivid dreams, often resoles over time
- Headache
- Weight changes (either up or down)
Other side effects:
- Sexual dysfunction (30-40%): decreased libido, anorgasmia, delayed ejaculation. These may occur weeks to months after taking an SSRI and typically do not resolve
- Restlessness: akathisia-like state
- Serotonin syndrome: Caused by excess of serotonin in body. Can result form a single agent or multiple agents in combo (eg triptans used with SSRIs)
- Hyponatremia (rare)
- Seizures: rate of approximately 0.2%, slightly lower than TCAs
SNRIs
Venlafaxine (Effexor)
Duloxetine (Cymbalta)
Venlafaxine (Effexor)
SNRI
- Often used for depressive disorders, anxiety disorders (like GAD), and neuropathic pain
- low drug interaction potential
- Etended release form allows for once-daily dosing
- Side effect profile similar to SSRIs, with the exception of increased BP in higher doses. Do not use in patients with untreated or labile BP
- New form, desvenlafaxine (Pristiq) is the active metabolite of venlafaxine; expensive and no known benefit over venlafaxine
Duloxetine (Cymbalta)
SNRI
- Often used for people with depression, neuropathic pain, and in fibromyalgia
- Side effects similar to SSRIs, but more dry mouth and constipation relating to neuroepinephrine effects
- Hepatotoxicity may be more likely in patients with liver disease or in heavy alcohol use, so LFTs should be monitored as indicated.
Bupropion (Wellbutrin)
NE-DA reuptake inhibitor
Lack of sexual side effects
Some efficacy in treatment of adult ADHD
Effective for smoking cessation
Weight neutral
Side effects include increased anxiety, as well as increased risk of seizures and psychosis at high doses
Contraindicated in patients with epilepsy or active eating disorders and in those currently on an MAOI. Use with caution with agents that also lower seizure threshold (stimulants)
Serotonin Receptor Antagonists and Agonists
Trazodone (Desyrel) and Nefazodone (Serzone)
- Useful in treatment of major depression, major depression with anxiety, and insomnia (secondary to sedative effects)
- Do not have sexual side effects of SSRIs and do not affect REM sleep
- Side effects: nausea, dizziness, orthostatic hypotension, cardiac arrhythmias, sedation, priapism (especially trazodone)
- Due to orthostatic hypotension at higher doses, trazodone is not frequently used as an antidepressant. Commonly used to treat insomnia when initiating an SSRI (until insomnia improves as the depression resolves)
- Nefazodone carries a black box warning for rare but serious liver failure (1 per 250,000-300,000 people) and is rarely used
Alpha-2 adrenergic receptor antagonists
Mirtazapine (Remeron)
- Useful in treatment of major depression, especially in patients who have significant weight loss or insomnia
- Side effects include sedation, weight gain, dizziness, tremor, dry mouth, constipation, and (rarely) agranulocytosis.
- Fewer sexual side effects compared to SSRIs and few drug interactions
- Helpful for treating major depression in the elderly - helps with sleep and appetite
Heterocyclic antidepressants: types and subtypes
Tricyclics (TCAs) - inhibit reuptake of NE and 5HT
- long half lives, dosed once daily
- rarely used as first-line agents due to side effects and lethality in overdose
- Tertiary amines: (high degree of HAM side effects):
1. Amitriptyline (Elavil)
2. Imipramine (Tofranil)
3. Clomipramine (Anafranil)
4. Doxepin (Sinequan) - Secondary amines: (metabolites of tertiary amines [less HAM]
1. Nortriptyline (Pamelor, Aventyl)
2. Desipramine (Norpramin)
- Tertiary amines: (high degree of HAM side effects):
Tetracyclics
1. Amoxapine
Amitriptyline (Elavil)
Tricyclic tertiary amine
Useful in chronic pain, migraines, insomnia
Imipramine (Tofranil)
Tricyclic tertiary amine
- Has IM form
- Useful in enuresis and panic disorder
Clomipramine (Anafranil)
Tricyclic tertiary amine
Most serotonin-specific, therefore useful in treatment of OCD
Doxepin (Sinequan)
Tricyclic tertiary amine
- Useful in treating chronic pain
- Emerging use as a sleep aid in low doses
Nortriptyline (Pamelor, Aventyl)
Tricyclic secondary amine
- Least likely to cause orthostatic hypotension
- Useful therapeutic blood levels
- Useful in treating chronic pain
Desipramine (Norpramin)
Tricyclic secondary amine
- More activating/less sedating
- Least anticholinergic
Amoxapine (Asendin)
Tetracyclic antidepressant
- Metabolite of antipsychotic loxapine
- May cause EPS and has a similar side-effect profile to typical antipsychotics
Side effects of TCAs
- Highly protein-bound and lipid soluble, therfore can interact with other meds that have high protein binding
- Antihistaminergic: sedation and weight gain
Antiadrenergic: CV - orthostatic hypotension, dizziness, reflex tachy, arrhythmias (block cardiac Na channels), ECG changes (widening QRS, QT, PR intervals). Avoid in patients with preexisting conduction abnormalities or recent MI** - Antimuscarinic (anticholinergic): Dry mouth, constipation, urinary retention, blurred vision, tachycardia,exacerbation of narrow angle glaucoma
- Lethal in overdose
- OD symptoms: agitation, tremors, ataxia, arrhythmias, delirium, hypoventilation from CNS depression, myoclonus, hyperreflexia, seizures, coma
- Seizures: risk is direct related to dose and serum level
- Serotonergic effects: Erectile/ejaculatory dysfunction in males, anorgasmia in females
Treatment of TCA overdose
Sodium bicarbonate
properties of MAO-Is
- Prevent inactivation of biogenic amines such as NE, 5HT, DA, tyramine
- Irreversibly inhibit MAO-A and MAO-B
- MAO-A preferentially deactivates serotonin and NE, and MAO-B preferentially deactivates phenethylamine, both types also act on DA and tyramine
- Not typically first line due to increased safety/tolerability of newer agents; can be used for refractory depression
MAOIs
Phenelzine (Nardil)
Tranylcypromine (Parnate)
Isocarboxazid (Marplan)
Selegeline (Emsam transdermal patch) - does not require following dietary restrictions when used in low dosages but still must avoid decongestants, opiates (such as meperidine, fentanyl, tramadol) and serotonergic drugs)
Side effects of MAOIs
- Serotonin syndrome occurs when SSRIs and MAOIs are taken together or if other drugs cause increases in serotonin levels **wait at least 2 weeks before switching from SSRI to MAOI and at least 5-6 weeks with fluoxetine
- Hypertensive crisis (risk when MAOIs are taken with tyramine-rich foods or sympathomimetics)
- Foods with tyramine (red wine, cheese, chicken liver, fava beans, cured meats) cause a buildup of stored catecholamines
- In addition to markedly elevated BP, it is also characterized by HA, sweating, n/v, photophobia, autonomic instability, CP, arrhythmia, death
- Foods with tyramine (red wine, cheese, chicken liver, fava beans, cured meats) cause a buildup of stored catecholamines
- Orthosatic hypotension (most common)**
- Drowsiness
- Weight gain
- Sexual dysfunction
- Dry mouth
- Sleep dysfunction
- Patients with pyridoxine deficiency can have numbness or paresthesias, so they should supplement with B6**
- Liver toxicity, seizures, edema (rare)
- “start low and go slow”
Antidepressant use in other disorders
OCD: SSRIs (high doses), TCAs (clomipramine)
Panic disorder: SSRIs, SNRIs, TCAs, MAOIs
Eating disorders: SSRIs (in high doses), TCAs
Persistent depressive disorder (dysthymia): SSRIs, SNRIs (eg venlafaxine, duloxetine)
Social anxiety disorder (social phobia): SSRIs, SNRIs, MAOIs
GAD: SSRIs, SNRIs (venlafaxine), TCAs
PTSD: SSRIs
IBS: SSRIs, TCAs
Enuresis: TCAs (imipramine)
Neuropathic pain: (TCAs (amitriptyline and nortriptyline), SNRIs
Chronic pain: SNRIs, TCAs
Fibromyalgia: SNRIs
Migraine: TCAs (amitriptyline)
Smoking cessation: Bupropion
PMDD: SSRIs
Insomnia: Mirtazapine, trazodone, TCAs (doxepin)
Parkinson’s: selegiline (MAO-B inhibitor)
Treatment of serotonin syndrome
First discontinue the med
Then provide supportive care and benzos
Serotonin antagonist cyproheptadine can also be used
Mechanisms of typical vs atypical antipsychotics
Typical: block dopamine D2
Atypical: block Serotonin 5HT2A
Efficacy of typical vs atypical antipsychotics on positive and negative symptoms
Positive symptoms - atypical and typical have similar efficacy
Negative symptoms - atypical antipsychotics may be more effective
Types of typical antipsychotics
Low-potency:
- Chlorpromazine (thorazine)
- Thioridazine (Mellaril)
Mid-potency:
- Loxapine (Loxitane)
- Thiothixene (Navane)
- Molindone (Moban)
- Perphenazine (Trilafon)
High-potency:
- Haloperidol (Haldol)
- Fluphenazine (Prolixin)
- Trifluoperazine (Stelazine)
- Pimozide (Orap)
Characteristics of low-potency, typical antipsychotics
- Lower affinity for dopamine receptors and therefore higher dose is required.
- Higher incidence of HAM side effects compared to high-potency
- Lower incidence of EPS and (possibly) neuroleptic malignant syndrome
- More lethality in OD due to QTc prolongation and potential for heart block and v-tach
- Rare risk for agranulocytosis and slightly higher seizure risk than high-potency
Drugs: Chlorpromazine (Thorazine)
Thioridazine (Mellaril)
Chlorpromazine (Thorazine)
Low-potency, typical antipsychotic
- Commonly causes orthostatic hypotension
- Can cause blue-gray skin discoloration as well as corneal and lens deposits
- Can lead to photosensitivity
- Also used to treat nausea and vomiting, as well as intractable hiccups
Thioridazine (Mellaril)
Low-potency, typical antipsychotic
- associated with retinitis pigmentosa
Loxapine (Loxitane)
Mid-potency, typical antipsychotic
- higher risk of seizures
- metabolite is an antidepressant
Thiothixene (Navane)
Mid-potency, typical antipsychotic
- can cause ocular pigment changes
Properties of high-potency, typical antipsychotics
- Greater affinity for dopamine receptors, therefore a relatively low dose is needed to achieve effect
- Less sedation, orthostatic hypotension, anticholinergic effects (less HAM)
- Greater risk for EPS and (likely) TD
Drugs: Haloperidol (Haldol), Fluphenazine (Prolixin), Trifluoperazine (Stelazine), Pimozide (Orap)
Haloperidol (Haldol)
High-potency, typical antipsychotic
- Can be given PO/IM/IV. Decanoate (long-acting) form available
Fluphenazine (Prolixin)
High-potency, typical antipsychotic
- Decanoate form available