Dextromethorphan + Bupropion

Dextromethorphan is an uncompetitive antagonist of the NMDA receptor and a sigma-1 receptor agonist. Bupropion increases plasma levels of Dextromethorphan by competitively inhibiting cytochrome P450 2D6. Bupropion is a relatively weak inhibitor of the neuronal reuptake of norepinephrine and dopamine and does not inhibit monoamine oxidase or the reuptake of serotonin.

• Major Depressive Disorder (MDD) in adults

Dextromethorphan is an uncompetitive antagonist of the NMDA receptor and a sigma-1 receptor agonist. Bupropion increases plasma levels of Dextromethorphan by competitively inhibiting cytochrome P450 2D6. Bupropion is a relatively weak inhibitor of the neuronal reuptake of norepinephrine and dopamine and does not inhibit monoamine oxidase or the reuptake of serotonin.

Dextromethorphan blocks NMDA receptors and activates sigma-1 receptors; Bupropion inhibits dextromethorphan metabolism to increase its plasma levels and inhibits norepinephrine/dopamine reuptake to help treat depression.

Adult: One tablet once daily in the morning for first 3 days; then increase to one tablet twice daily (at least 8 hours apart). Do not exceed two doses in the same day.
Moderate renal impairment: One tablet once daily in the morning.
Strong CYP2D6 inhibitors: One tablet once daily in the morning.

Take in the morning with or without food. Swallow the tablet whole, do not chew, crush or break.

If you miss a dose, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose. Do not double the dose.

Common: Dizziness, headache, somnolence, diarrhea, dry mouth, sexual dysfunction, hyperhidrosis.

Seizure risk is dose-related; discontinue if seizure occurs. Increased blood pressure and hypertension may occur; assess blood pressure before and during treatment. Screen for bipolar disorder. Instruct patients to contact healthcare provider if psychosis or other neuropsychiatric reactions occur.

Seizure disorder; current or prior diagnosis of bulimia or anorexia nervosa; abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs; use with an MAOI or within 14 days of stopping MAOI; known hypersensitivity.

Strong CYP2D6 inhibitors: Reduce dose to once daily.
Strong CYP2B6 inducers: Avoid use.
CYP2D6 substrates: Increases exposures.
Digoxin: May decrease plasma levels; monitor digoxin levels.
Drugs that lower seizure threshold: May increase risk of seizure.
Dopaminergic drugs: CNS toxicity can occur.

Can be taken with or without food.

Insufficient clinical data on use during pregnancy. First trimester bupropion exposure has not been identified with increased risk of congenital malformations overall.

Bupropion and its metabolites are present in human milk. Limited post-marketing data have not identified a clear association of adverse reactions in breastfed infants.

Safety and effectiveness in pediatric patients have not been established. Antidepressants, including bupropion, increase the risk of suicidal thoughts and behaviors in pediatric patients.

No specific dosage adjustment is necessary for elderly patients.

Renal impairment: Moderate renal impairment: one tablet once daily in the morning.
Hepatic impairment: No adequate information available.

Overdose may produce effects of individual components; overdose may be more severe or persistent due to bupropion inhibiting dextromethorphan metabolism.

Store at or below 30°C. Keep away from light and moisture. Keep out of reach of children.

Dextromethorphan + Bupropion