Dextromethorphan hydrobromide and quinidine sulfate
Generic: DEXTROMETHORPHAN HYDROBROMIDE AND QUINIDINE SULFATE
Basic Information
Manufacturer
Camber Pharmaceuticals, Inc.
Product Type
HUMAN PRESCRIPTION DRUG
Route of Administration
ORAL
FDA Set ID
7028dcb7-f436-4cf6-9beb-23c1d215c798
Indications & Usage
1 INDICATIONS AND USAGE Dextromethorphan hydrobromide and quinidine sulfate capsules are indicated for the treatment of pseudobulbar affect (PBA).
PBA occurs secondary to a variety of otherwise unrelated neurologic conditions, and is characterized by involuntary, sudden, and frequent episodes of laughing and/or crying.
PBA episodes typically occur out of proportion or incongruent to the underlying emotional state.
PBA is a specific condition, distinct from other types of emotional lability that may occur in patients with neurological disease or injury.
Dextromethorphan hydrobromide and quinidine sulfate capsules are a combination product containing dextromethorphan hydrobromide (an uncompetitive NMDA receptor antagonist and sigma-1 agonist) and quinidine sulfate (a CYP450 2D6 inhibitor) indicated for the treatment of pseudobulbar affect (PBA).
( 1 )
PBA occurs secondary to a variety of otherwise unrelated neurologic conditions, and is characterized by involuntary, sudden, and frequent episodes of laughing and/or crying.
PBA episodes typically occur out of proportion or incongruent to the underlying emotional state.
PBA is a specific condition, distinct from other types of emotional lability that may occur in patients with neurological disease or injury.
Dextromethorphan hydrobromide and quinidine sulfate capsules are a combination product containing dextromethorphan hydrobromide (an uncompetitive NMDA receptor antagonist and sigma-1 agonist) and quinidine sulfate (a CYP450 2D6 inhibitor) indicated for the treatment of pseudobulbar affect (PBA).
( 1 )
Adverse Reactions
6 ADVERSE REACTIONS A total of 946 patients participated in four Phase 3 controlled and uncontrolled PBA studies and received at least one dose of the combination product of dextromethorphan/quinidine in various strengths at the recommended or higher than the recommended dose.
Of those patients, 393 patients were exposed for at least 180 days and 294 patients were exposed for at least one year.
Median exposure was 168 days.
Controlled trials enrolled only patients with either ALS or MS.
Uncontrolled studies enrolled 136 patients with PBA secondary to a wide variety of underlying neurological conditions including stroke (45 patients) and traumatic brain injury (23 patients).
Consequently, patients with other underlying neurologic diseases may experience other adverse reactions not described below.
The most common adverse reactions (incidence of ≥ 3% and two-fold greater than placebo) in patients taking dextromethorphan hydrobromide and quinidine sulfate are diarrhea, dizziness, cough, vomiting, asthenia, peripheral edema, urinary tract infection, influenza, increased gamma-glutamyltransferase, and flatulence.
( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Hetero Labs Limited at 1-866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1 Clinical Trials Experience A 12-week, placebo-controlled study evaluated dextromethorphan hydrobromide and quinidine sulfate (dextromethorphan 20 mg/quinidine 10 mg) (N=107) and a 30 mg dextromethorphan/10 mg quinidine combination (N=110) compared to placebo (N=109).
Approximately 60% of patients had ALS and 40% had MS.
Patients were 25 to 80 years of age, with a mean age of approximately 51 years.
Three (3) ALS patients in each drug treatment arm and 1 ALS patient in the placebo arm died during the 12-week placebo-control period.
All deaths were consistent with the natural progression of ALS.
Adverse Reactions Leading to Discontinuation The most commonly reported adverse reactions (incidence ≥ 2% and greater than placebo) that led to discontinuation with the 20 mg dextromethorphan/10 mg quinidine twice daily dose were muscle spasticity (3%), respiratory failure (1%), abdominal pain (2%), asthenia (2%), dizziness (2%), fall (1%), and muscle spasms (2%).
Most Common Adverse Reactions Adverse drug reactions that occurred in ≥ 3% of patients receiving the 20 mg dextromethorphan/10 mg quinidine twice daily dose, and at an incidence of ≥ 2 times placebo in short-term clinical trials in ALS and MS are provided in Table 1.
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to the rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
Table 1: Adverse Drug Reactions with an Incidence of ≥3% of Patients and ≥ 2x Placebo in Dextromethorphan Hydrobromide and Quinidine Sulfate-treated Patients by System-Organ Class and Preferred Term Dextromethorphan Hydrobromide and Quinidine Sulfate N=107 % Placebo N=109 % Diarrhea 13 6 Dizziness 10 5 Cough 5 2 Vomiting 5 1 Asthenia 5 2 Peripheral edema 5 1 Urinary tract infection 4 1 Influenza 4 1 Increased gamma- glutamyltransferase 3 0 Flatulence 3 1 6.2 Long-Term Exposure with Dextromethorphan Hydrobromide and Quinidine Sulfate The experience in open-label clinical trials is consistent with the safety profile observed in the placebo-controlled clinical trials.
6.3 Safety Experience of Individual Components The following adverse reactions have been reported with the use of the individual components of dextromethorphan hydrobromide and quinidine sulfate, dextromethorphan and quinidine, from post-marketing experience.
Because these reactions are reported voluntarily from a population of unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Dextromethorphan Drowsiness, dizziness, nervousness or restlessness, nausea, vomiting, and stomach pain.
Quinidine Cinchonism is most often a sign of chronic quinidine toxicity, but it may appear in sensitive patients after a single moderate dose of several hundred milligrams.
Cinchonism is characterized by nausea, vomiting, diarrhea, headache tinnitus, hearing loss, vertigo, blurred vision, diplopia, photophobia, confusion, and delirium.
Convulsions, apprehension, and ataxia have been reported with quinidine therapy, but it is not clear that these were not simply the results of hypotension and consequent cerebral hypoperfusion in patients being treated for cardiovascular indications.
Acute psychotic reactions have been reported to follow the first dose of quinidine, but these reactions appear to be extremely rare.
Other adverse reactions occasionally reported with quinidine therapy include depression, mydriasis, disturbed color perception, night blindness, scotomata, optic neuritis, visual field loss, photosensitivity, keratopathy, and abnormalities of skin pigmentation.
Of those patients, 393 patients were exposed for at least 180 days and 294 patients were exposed for at least one year.
Median exposure was 168 days.
Controlled trials enrolled only patients with either ALS or MS.
Uncontrolled studies enrolled 136 patients with PBA secondary to a wide variety of underlying neurological conditions including stroke (45 patients) and traumatic brain injury (23 patients).
Consequently, patients with other underlying neurologic diseases may experience other adverse reactions not described below.
The most common adverse reactions (incidence of ≥ 3% and two-fold greater than placebo) in patients taking dextromethorphan hydrobromide and quinidine sulfate are diarrhea, dizziness, cough, vomiting, asthenia, peripheral edema, urinary tract infection, influenza, increased gamma-glutamyltransferase, and flatulence.
( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Hetero Labs Limited at 1-866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1 Clinical Trials Experience A 12-week, placebo-controlled study evaluated dextromethorphan hydrobromide and quinidine sulfate (dextromethorphan 20 mg/quinidine 10 mg) (N=107) and a 30 mg dextromethorphan/10 mg quinidine combination (N=110) compared to placebo (N=109).
Approximately 60% of patients had ALS and 40% had MS.
Patients were 25 to 80 years of age, with a mean age of approximately 51 years.
Three (3) ALS patients in each drug treatment arm and 1 ALS patient in the placebo arm died during the 12-week placebo-control period.
All deaths were consistent with the natural progression of ALS.
Adverse Reactions Leading to Discontinuation The most commonly reported adverse reactions (incidence ≥ 2% and greater than placebo) that led to discontinuation with the 20 mg dextromethorphan/10 mg quinidine twice daily dose were muscle spasticity (3%), respiratory failure (1%), abdominal pain (2%), asthenia (2%), dizziness (2%), fall (1%), and muscle spasms (2%).
Most Common Adverse Reactions Adverse drug reactions that occurred in ≥ 3% of patients receiving the 20 mg dextromethorphan/10 mg quinidine twice daily dose, and at an incidence of ≥ 2 times placebo in short-term clinical trials in ALS and MS are provided in Table 1.
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to the rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
Table 1: Adverse Drug Reactions with an Incidence of ≥3% of Patients and ≥ 2x Placebo in Dextromethorphan Hydrobromide and Quinidine Sulfate-treated Patients by System-Organ Class and Preferred Term Dextromethorphan Hydrobromide and Quinidine Sulfate N=107 % Placebo N=109 % Diarrhea 13 6 Dizziness 10 5 Cough 5 2 Vomiting 5 1 Asthenia 5 2 Peripheral edema 5 1 Urinary tract infection 4 1 Influenza 4 1 Increased gamma- glutamyltransferase 3 0 Flatulence 3 1 6.2 Long-Term Exposure with Dextromethorphan Hydrobromide and Quinidine Sulfate The experience in open-label clinical trials is consistent with the safety profile observed in the placebo-controlled clinical trials.
6.3 Safety Experience of Individual Components The following adverse reactions have been reported with the use of the individual components of dextromethorphan hydrobromide and quinidine sulfate, dextromethorphan and quinidine, from post-marketing experience.
Because these reactions are reported voluntarily from a population of unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Dextromethorphan Drowsiness, dizziness, nervousness or restlessness, nausea, vomiting, and stomach pain.
Quinidine Cinchonism is most often a sign of chronic quinidine toxicity, but it may appear in sensitive patients after a single moderate dose of several hundred milligrams.
Cinchonism is characterized by nausea, vomiting, diarrhea, headache tinnitus, hearing loss, vertigo, blurred vision, diplopia, photophobia, confusion, and delirium.
Convulsions, apprehension, and ataxia have been reported with quinidine therapy, but it is not clear that these were not simply the results of hypotension and consequent cerebral hypoperfusion in patients being treated for cardiovascular indications.
Acute psychotic reactions have been reported to follow the first dose of quinidine, but these reactions appear to be extremely rare.
Other adverse reactions occasionally reported with quinidine therapy include depression, mydriasis, disturbed color perception, night blindness, scotomata, optic neuritis, visual field loss, photosensitivity, keratopathy, and abnormalities of skin pigmentation.