Dextromethorphan + Bupropion

Major depressive disorder (MDD) in adults.

This is a combined preparation of Dextromethorphan Hydrobromide and Bupropion Hydrochloride. Dextromethorphan is an uncompetitive antagonist of the NMDA receptor (an ionotropic glutamate receptor) and a sigma-1 receptor agonist. The mechanism of Dextromethorphan in the treatment of MDD is unclear. The mechanism of action of bupropion in the treatment of MDD is unclear; however, it may be related to noradrenergic and/or dopaminergic mechanisms. Bupropion increases plasma levels of Dextromethorphan by competitively inhibiting cytochrome P450 2D6, which catalyzes a major biotransformation pathway for Dextromethorphan. 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.

Starting dosage: One tablet once daily in the morning. After 3 days, increase to the maximum recommended dosage of one tablet twice daily, separated by at least 8 hours. Do not exceed two doses within the same day.

Moderate renal impairment: One tablet by mouth once daily in the morning.

Strong CYP2D6 inhibitors: Recommended dosage is one tablet by mouth
once daily in the morning.
Strong CYP2B6 inducers: Avoid use.
CYP2D6 Substrates: Increases the exposures of drugs that are substrates of CYP2D6.
Digoxin: May decrease plasma digoxin levels. Monitor digoxin levels.
Drugs that lower seizure threshold: Coadministration may increase risk of seizure.
Dopaminergic drugs: Central Nervous System (CNS) toxicity can occur with concomitant use.

• 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 treatment with this combination. Do not use this within 14 days of discontinuing an MAOI.
• Known hypersensitivity.

• Dizziness, headache, somnolence
• Diarrhea, dry mouth
• Sexual dysfunction
• Hyperhidrosis

The available clinical data on the use of this combination during pregnancy is insufficient to evaluate for a drug-associated risk of major birth malformations, miscarriage, or other adverse maternal or fetal outcomes. However, there are available data on one of the individual components of this combination, bupropion. Data from epidemiological studies of pregnant women exposed to bupropion in the first trimester have not identified an increased risk of congenital malformations overall. There are risks to the mother associated with untreated depression in pregnancy. Data from published literature report the presence of bupropion and its metabolites in human milk. There are no data on the effects of bupropion or its metabolites on milk production. Limited data from post-marketing reports of bupropion use in lactating patients have not identified a clear association of adverse reactions in the breastfed infant.

• Seizure: Risk is dose-related. Discontinue if seizure occurs.
• Increased Blood Pressure and Hypertension: this combination can increase blood pressure and cause hypertension. Assess blood pressure before initiating treatment and monitor periodically during treatment.
• Activation of Mania or Hypomania: Screen patients for bipolar disorder.
• Psychosis and Other Neuropsychiatric Reactions: Instruct patients to contact a healthcare provider if such reactions occur.

There is limited clinical study experience regarding human overdosage with this combination. Overdosage information is based on experience with the individual components, Dextromethorphan and Bupropion. Metabolism of the Dextromethorphan component of this combination is inhibited by the Bupropion component, such that overdose due to this combination might be more severe or more persistent compared to overdose of dextromethorphan alone.

Combined anxiolytics & anti-depressant drugs

Store at or below 30˚C temperature. Keep away from light and wet place. Keep out of reach of children. Do not store in wet place. Keep away from light. Keep out of reach of children.