Cymbalta Vs. Gabapentin: Drug Comparison

Cymbalta^® (duloxetine) is a serotonin-norepinephrine reuptake inhibitor (SNRI) used to treat depression and anxiety by increasing the available levels of serotonin and norepinephrine in the brain, which helps improve mood and relieve pain. Its FDA-approved indications include major depressive disorder (MDD), generalized anxiety disorder (GAD), fibromyalgia, and chronic pain conditions such as diabetic peripheral neuropathy and musculoskeletal pain. Off-label uses may include treatment for stress urinary incontinence and as migraine prevention. Cymbalta is available in capsule form, taken orally. Common side effects include nausea, dry mouth, drowsiness, and dizziness, and it carries a boxed warning for an increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults, especially during the initial stages of treatment.

Gabapentin is an anticonvulsant medication that works by affecting the brain's neurotransmitters to reduce nerve-related pain and prevent seizures. Its FDA-approved indications include the treatment of partial seizures and neuropathic pain associated with conditions including postherpetic neuralgia (pain following shingles). Off label, gabapentin is commonly used for anxiety, fibromyalgia, and chronic pain management. It is available in oral forms such as capsules, tablets, and solutions. Common side effects include drowsiness, dizziness, and fatigue, while serious risks include respiratory depression when combined with central nervous system (CNS) depressants like opioids. Caution is advised when prescribing to patients with respiratory issues or those taking sedatives.

Serotonin and norepinephrine reuptake inhibitor (SNRI)

Anticonvulsant

Cymbalta (duloxetine hydrochloride) is indicated for the treatment of the following conditions:

• Major depressive disorder (MDD) in adults

• Generalized anxiety disorder (GAD) in adults and pediatric patients 7 years of age and older

• Diabetic peripheral neuropathic pain (DPNP) in adults

• Fibromyalgia (FM) in adults and pediatric patients 13 years of age and older

• Chronic musculoskeletal pain in adults

Gabapentin is indicated for:

• Postherpetic neuralgia in adults

• Adjunctive therapy in the treatment of partial onset seizures, with and without secondary generalization, in adults and pediatric patients 3 years and older with epilepsy

• Typically taken orally once daily

• Comes in 20 mg, 30 mg, and 60 mg delayed-release capsules

• Typically taken orally once, twice, or three times daily

• Comes in 100 mg, 300 mg, and 400 mg capsules

Most common adverse reactions (≥5% and at least twice the incidence of placebo-treated patients):

Adults:

• Nausea

• Dry mouth

• Sleepiness

• Constipation

• Decreased appetite

• Excessive sweating

Pediatric patients:

• Decreased weight

• Decreased appetite

• Nausea

• Vomiting

• Fatigue

• Diarrhea

Most common adverse reactions (incidence ≥8% and at least twice that for placebo) were:

Postherpetic neuralgia:

• Dizziness

• Sleepiness

• Swelling in the extremities

Epilepsy in patients >12 years of age:

• Sleepiness

• Dizziness

• Poor muscle control

• Fatigue

• Uncontrolled eye movements

Epilepsy in patients 3 to 12 years of age:

• Viral infection

• Fever

• Nausea and/or vomiting

• Slepiness

• Hostility

• Concomitant use of an MAOI antidepressant with Cymbalta is contraindicated

• Use of Cymbalta within 14 days of stopping an MAOI antidepressant is contraindicated

• In linezolid- or intravenous methylene blue-treated patients, initiation of Cymbalta is contraindicated

• Drug interactions: potent inhibitors of CYP1A2, potent inhibitors of CYP2D6

• Known hypersensitivity to gabapentin or its ingredients

• Drug interactions: morphine

• Liver toxicity

• Postural low blood pressure, falls, and fainting

• Serotonin syndrome

• Increased risk of bleeding

• Severe skin reactions

• Activation of mania or hypomania

• Angle-closure glaucoma

• Seizures

• Blood pressure increases

• Inhibitors of CYP1A2 or thioridazine: Avoid co-administration with Cymbalta

• Low blood sodium: Can occur in association with SIADH

• Glucose control in diabetes

• Conditions that slow gastric emptying

• Sexual dysfunction

• Pregnancy: Third trimester use may increase risk for symptoms of poor adaptation (respiratory distress, temperature instability, feeding difficulty, hypotonia, tremor, irritability) in the neonate

• Drug reaction with eosinophilia and systemic symptoms (multiorgan hypersensitivity)

• Anaphylaxis and angioedema

• Driving impairment; somnolence/sedation and dizziness

• Increased seizure frequency may occur in patients with seizure disorders if gabapentin is abruptly discontinued

• Suicidal behavior and ideation

• Respiratory depression: May occur with gabapentin when used with concomitant central nervous system (CNS) depressants, including opioids, or in the setting of underlying respiratory impairment

• Neuropsychiatric adverse reactions in children 3 to 12 years of age

• Pregnancy: Based on animal data, may cause fetal harm

WARNING: SUICIDAL THOUGHTS AND BEHAVIORS

Increased risk of suicidal thinking and behavior in children, adolescents, and young adults taking antidepressants.

Monitor for worsening and emergence of suicidal thoughts and behaviors.

*This information is from the label for brand name Cymbalta^®. See the Full Prescribing Information for more complete information. Duloxetine, the active ingredient in Cymbalta, may also be the active ingredient in other medications, and this information may not be accurate for all medications that include the active ingredient duloxetine.

*This information is from the gabapentin label used by ACI Healthcare USA, Inc. See the Full Prescribing Information for more complete information. This information may not be accurate for all medications that include the active ingredient gabapentin.