DULOXETINE HYDROCHLORIDE

DULOXETINE HYDROCHLORIDE
(du-lox'e-teen)
Cymbalta
Classifications: psychotherapeutic agent; antidepressant; serotonin norepinephrine reuptake inhibitor (snri);
Therapeutic: antidepressant; snri; neuropathic pain reliever
Prototype: Venlafaxine
Pregnancy Category: C

Availability

20 mg, 30 mg, 60 mg capsules

Action

As a selective serotonin and norepinephrine reuptake inhibitor (SSNRI), duloxetine causes potentiation of serotonergic and noradrenergic activity in the CNS.

Therapeutic Effect

Antidepressant effect is presumed to be due to its dual inhibition of CNS presynaptic neuronal uptake of serotonin and norepinephrine, thus increasing the serum levels of both substances.

Uses

Treatment of major depression, diabetic peripheral neuropathy.

Unlabeled Uses

Chronic pain syndromes.

Contraindications

Concurrent administration of MAOI therapy; uncontrolled narrow-angle glaucoma; alcoholism; chronic hepatic disease; hepatitis; jaundice; abrupt discontinuation; pregnancy (category C), third trimester of pregnancy, lactation. Safety and efficacy in children <18 y not established.

Cautious Use

Anorexia nervosa, bipolar disease; history of mania, history of suicidal ideation; cardiac disease; renal impairment or renal failure; hypertension.

Route & Dosage

Depression
Adult: PO 40–60 mg/d in one or two divided doses

Diabetic Neuropathy or Chronic Pain
Adult: PO 60 mg/d in one or two divided doses

Administration

Oral

Do not initiate therapy within 14 d of the last dose of an MAOI.
Must be swallowed whole. Do not cut, chew, or crush. Do not sprinkle on food or mix with liquids.
Store at 15°–30° C (59°–86° F).

Adverse Effects (≥1%)

Body as a Whole: Fatigue, hot flashes. CNS: Dizziness, somnolence, tremor, insomnia. GI: Nausea, dry mouth, constipation, diarrhea, vomiting. Metabolic: Decreased appetite, weight loss. Skin: Increased sweating. Special Senses: Blurred vision. Urogenital: Decreased libido, abnormal orgasm, erectile dysfunction, ejaculatory dysfunction. Cholestatic jaundice and hepatitis.

Interactions

Drug: Alcohol may result in increased liver function tests; maois may result in hyperthermia, rigidity, mental status changes, myoclonus, autonomic instability, features resembling neuroleptic malignant syndrome; cimetidine, fluoxetine, fluvoxamine, paroxetine, quinidine, quinolones may increase levels and half-life of duloxetine; may increase levels and toxicity of thioridazine, tricyclic antidepressants. Amphetamine, dextroamphetamine, buspirone, cocaine, dexfenfluramine, fenfluramine, lithium, phentermine, sibutramine, nefazodone, ssris, triptans, tramadol, trazodone may cause serotonin syndrome. Herbal: St. John's wort, tryptophan may cause serotonin syndrome.

Pharmacokinetics

Peak: 6 h. Metabolism: In the liver by CYP2D6 and CYP1A2. Elimination: 70% in urine, 20% in feces. Half-Life: 12 h (8–17 h).

Nursing Implications

Assessment & Drug Effects

Ensure that a complete list of all concurrent medications is obtained.
Monitor for S&S of numerous drug-drug interactions (see Interaction section).
Lab test: LFTs for unexplained abdominal pain or enlarged liver.
Monitor closely for and report suicide ideation, especially when drug is initiated or dosage changed.
Report emergence of any of the following: anxiety, agitation, panic attacks, insomnia, irritability, hostility, psychomotor restlessness, hypomania, and mania.
Monitor BP, especially in those being treated for hypertension.

Patient & Family Education

The beneficial effects of this drug may not be felt for approximately 4 wk.
Report any of the following: suicidal ideation (especially early in treatment or when dosage is changed), palpitations, anxiety, hyperactivity, agitation, panic attacks, insomnia, irritability, hostility, restlessness.
Do not abruptly discontinue taking this drug. Notify physician if side effects are bothersome.
Avoid or minimize use of alcohol while taking this drug.
Do not self-treat for coughs, colds, or allergies. Consult physician.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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