Functional class
Func. class.: Antidepressant, SSRI
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Drug reference
Func. class.: Antidepressant, SSRI
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Chem. class.: Phenylpiperidine derivative
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Do not confuse: PARoxetine/FLUoxetine/Piroxicam/ PACLitaxel Paxil/PACLitaxel/Taxol/doxil
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ACTION: Inhibits CNS neuron uptake of serotonin but not of norepinephrine or DOPamine
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USES: Major depressive disorder, obsessive-compulsive disorder, panic disorder, generalized anxiety disorder, posttraumatic stress disorder, premen strual disorders, social anxiety disorder, hot flashes, menopause
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Unlabeled uses: Premature ejaculation (IR only)
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CONTRAINDICATIONS: Preg nancy, hypersensitivity, MAOI use, alcohol use Precautions: Breastfeeding, geriatric patients, seizure history; patients with history of mania, renal/hepatic disease
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Black Box Warning: Children, suicidal ideation Black Box Warning: Depression/OCD/ anxiety/panic attacks: mental status: mood, sensorium, affect, suicidal ten- dencies (especially in child/young adult), increase in psychiatric symptoms, de- creasing obsessive thoughts, compulsive behaviors, restrict amount available • Postural hypotension: B/P (lying/ standing), pulse q4hr; if systolic B/P drops 20 mm Hg, hold product, notify prescriber; take vital signs q4hr for pa- tients with CV disease • Hepatic/renal studies: AST, ALT, biliru- bin, creatinine • Weight weekly; appetite may decrease with product, but weight gain may occur; constipation • EPS, primarily in geriatric patients: ri- gidity, dystonia, akathisia • Renal status: BUN, creatinine, urinary retention • Withdrawal symptoms: headache, nausea, vomiting, muscle pain, weak- ness; not usual unless product discontin- ued abruptly, taper over 1-2 wk • Alcohol intake; if alcohol is consumed, hold dose until morning • Serotonin, neuroleptic malignant syn- drome: hallucinations, coma, headache, agitation, shivering, sweating, tachycardia, diarrhea, tremors, hypertension, hyperther- mia, rigidity, delirium, coma, myoclonus, agitation, nausea, vomiting • Beers: Avoid in geriatrics, highly anti- cholinergic, sedating • Pregnancy/breastfeeding: use only if clearly needed; do not breastfeed Black Box Warning: That depression, suicidal thoughts/behaviors in children/ adolescents or young adults may worsen, to notify prescriber immediately • To avoid alcohol ingestion, OTC prod- ucts unless approved by prescriber • To report bleeding, headache, nausea, anxiety, or if depression continues • To discuss sexual side effects: impo- tence, possible male infertility while taking product
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SIDE EFFECTS CNS: Headache, nervousness, insomnia, drowsiness, anxiety, tremors, dizziness, fatigue, sedation, abnormal dreams, agi- tation, apathy, euphoria, hallucinations, delusions, psychosis, seizures CV: Vasodilation, postural hypotension, palpitations, bleeding, chest pain EENT: Visual changes GI: Nausea, diarrhea, dry mouth, anorexia, dyspepsia, constipation, cramps, vomiting, taste changes, flatu- lence, decreased appetite, weight gain GU: Dysmenorrhea, decreased libido, urinary frequency, UTI, amenorrhea, cys- titis, impotence; decreased sperm qual- ity, decreased fertility, abnormal ejacu lation (male) INTEG: Sweating, rash, photosensitivity MS: Pain, arthritis, myalgia, myopathy RESP: Infection, pharyngitis, nasal con- gestion, sinus headache, sinusitis, cough, dyspnea, yawning SYST: Fever, abrupt withdrawal syn- drome, Stevens-Johnson syndrome, neu- roleptic malignant syndrome, suicidal thoughts/behaviors
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INTERACTIONS Increase: serotonin syndrome—SSRIs, SNRIs, atypical psychotics, serotonin- receptor agonists, tricyclics, amphet- amines, bupropion, cyclobenzaprine, line- zolid, traMADol Decrease: level of digoxin • Do not use with MAOIs, pimozide, thiorid- azine; potentially fatal reactions can occur Increase: bleeding—NSAIDs, thrombo- lytics, salicylates, platelet inhibitors, anticoagulants Increase: PARoxetine plasma levels— cimetidine Increase: agitation—l-tryptophan Increase: side effects—highly protein- bound products Increase: theophylline levels—theophylline Increase: toxicity—CYP2D6 inhibitors (aprepitant, delavirdine, imatinib, nefazodone) Decrease: PARoxetine levels—PHENo- barbital and phenytoin Drug/Herb • SAMe • Possible serotonin syndrome: St. John’s wort, tryptophan • Hypertensive crisis: ephedra
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TREATMENT OF OVERDOSE: Gastric lavage, airway; for seizures, give diazepam, symptomatic treatment
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DOSAGE AND ROUTES Generalized anxiety disorder • Adult: PO 20 mg/day in am, range 20- 50 mg/day Posttraumatic stress disorder (PTSD) • Adult: PO 20 mg/day, range 20-50 mg/ day; max 50 mg/day Depression • Adult: PO 20 mg/day in am; after 4 wk, if no clinical improvement is noted, dose may be increased by 10 mg/day each wk to desired response, max 50 mg/day or CONT REL 25 mg/day, may increase by 12.5 mg/day/wk up to 62.5 mg/day • Geriatric: PO 10 mg/day, increase by 10 mg to desired dose, max 40 mg/day Obsessive-compulsive disorder • Adult: PO 40 mg/day in am, start with 20 mg/day, increase in 10-mg/day incre- ments, max 60 mg/day P Panic disorder • Adult: PO start with 10 mg/day, in- crease in 10-mg/day increments to 40 mg/day, max 60 mg/day or CONT REL 12.5 mg/day, max 75 mg/day Premenstrual dysphoric disorders • Adult: CONT REL 12.5 mg/day in am Menopause symptoms/hot flashes • Adult: PO (CONT REL) 12.5 mg/day, may increase to 25 mg/day after 1 wk Premature ejaculation (unlabeled) • Adult: PO 20 mg/day Renal dose • Adult: PO CCr 30-60 mL/min, lower doses may be needed; CCr <30 mL/min, 10 mg/day initially, REGULAR RELEASE: max 40 mg/ day; CONTINUOUS RELEASE 12.5 mg/day initially, max 50 mg/day Hepatic dose • Adult: PO 10 mg/day initially, max 40 mg (REGULAR RELEASE); 12.5 mg/day ini- tially, max 50 mg/day (CONTINUOUS RE- LEASE)
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Available forms: Tabs 10, 20, 30, 40 mg; oral susp 10 mg/5 mL; cont rel tab 12.5, 25, 37.5 mg; cap 7.5 mg
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Administer: • Do not substitute Pexeva with Paxil, Paxil CR, or generic PARoxetine • Store at room temperature; do not freeze • Increased fluids, bulk in diet for con- stipation, urinary retention • With food, milk for GI symptoms • Crushed if patient is unable to swallow medication whole (regular rel only) • Gum, hard candy, frequent sips of wa- ter for dry mouth • Avoid use with other CNS depressants • Oral susp: shake, measure with oral syringe or calibrated measuring device • Cont rel tab: do not cut, chew, crush; do not give concurrently with antacids
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Assess:
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Evaluate: • Therapeutic response: decreased de- pression
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • That therapeutic effect may take 1-4 wk • To use caution when driving, performing other activities requiring alertness because of drowsiness, dizziness, blurred vision • Not to discontinue medication quickly after long-term use; may cause nausea, headache, malaise (abrupt withdrawal syn- drome)
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PHARMACOKINETICS PO: Peak 5.2 hr, ext rel peak 6-10 hr; metabolized in liver by CYP2D6 enzyme system, 7% may be poor metaboliz- ers; unchanged products and metabolites excreted in feces and urine; half-life 21 hr (reg rel); 15-20 hr (cont rel); protein binding 95%
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• Adult: PO 20 mg/day in am, range 20- 50 mg/day Posttraumatic stress disorder (PTSD)
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• Adult: PO 20 mg/day, range 20-50 mg/ day; max 50 mg/day Depression
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• Adult: PO 20 mg/day in am; after 4 wk, if no clinical improvement is noted, dose may be increased by 10 mg/day each wk to desired response, max 50 mg/day or CONT REL 25 mg/day, may increase by 12.5 mg/day/wk up to 62.5 mg/day
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• Geriatric: PO 10 mg/day, increase by 10 mg to desired dose, max 40 mg/day Obsessive-compulsive disorder
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• Adult: PO 40 mg/day in am, start with 20 mg/day, increase in 10-mg/day incre- ments, max 60 mg/day P Panic disorder
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• Adult: PO start with 10 mg/day, in- crease in 10-mg/day increments to 40 mg/day, max 60 mg/day or CONT REL 12.5 mg/day, max 75 mg/day Premenstrual dysphoric disorders
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• Adult: CONT REL 12.5 mg/day in am Menopause symptoms/hot flashes
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• Adult: PO (CONT REL) 12.5 mg/day, may increase to 25 mg/day after 1 wk Premature ejaculation (unlabeled)
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• Adult: PO 20 mg/day Renal dose
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• Adult: PO CCr 30-60 mL/min, lower doses may be needed; CCr <30 mL/min, 10 mg/day initially, REGULAR RELEASE: max 40 mg/ day; CONTINUOUS RELEASE 12.5 mg/day initially, max 50 mg/day Hepatic dose
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• Adult: PO 10 mg/day initially, max 40 mg (REGULAR RELEASE); 12.5 mg/day ini- tially, max 50 mg/day (CONTINUOUS RE- LEASE)
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