Why is this medication prescribed?

Dextromethorphan and quinidine are typically prescribed together to treat a neurological condition called pseudobulbar affect (PBA). PBA is characterized by uncontrollable outbursts of laughing or crying that are disproportionate to the individual’s emotional state.

Dextromethorphan is a cough suppressant that also affects certain brain chemicals involved in controlling mood and emotions, while quinidine helps increase the levels of dextromethorphan in the body by slowing down its breakdown. Together, they help regulate emotions and reduce the frequency and severity of PBA episodes.

How should this medicine be used?

When using dextromethorphan and quinidine, it’s essential to follow your doctor’s instructions carefully. Typically, the medication is taken orally in capsule form, usually once or twice a day. Dosage and frequency may vary depending on the severity of PBA and individual response to the medication.

It’s crucial not to crush, chew, or break the capsules, as this can alter the release of the medication and may lead to unwanted side effects. Take the capsules whole with water, with or without food, as directed by your doctor.

Never exceed the prescribed dosage or change the dosing schedule without consulting your healthcare provider, as doing so may increase the risk of side effects or reduce the effectiveness of the treatment. If you have any questions or concerns about how to use dextromethorphan and quinidine, be sure to discuss them with your doctor or pharmacist.

Other uses for this medicine

Apart from treating pseudobulbar affect (PBA), dextromethorphan and quinidine have been investigated for their potential therapeutic effects in other conditions. Some studies suggest they may have benefits in managing neuropathic pain, although more research is needed to confirm these findings. Additionally, dextromethorphan has been explored for its potential in treating depression and certain types of cough, while quinidine is primarily used to treat irregular heart rhythms (arrhythmias).

What special precautions should I follow?

When taking dextromethorphan and quinidine, there are several special precautions to keep in mind:

• Medical History: Inform your healthcare provider about your medical history, especially if you have a history of heart problems, liver or kidney disease, seizures, breathing disorders, or if you’re taking any other medications, including prescription and over-the-counter drugs, as well as dietary supplements.
• Allergies: Let your doctor know if you have any allergies to dextromethorphan, quinidine, or any other substances.
• Pregnancy and Breastfeeding: If you are pregnant or breastfeeding, discuss the risks and benefits of using dextromethorphan and quinidine with your healthcare provider before starting the medication.
• Driving and Operating Machinery: Dextromethorphan and quinidine may cause dizziness, drowsiness, or blurred vision. Avoid driving, operating machinery, or engaging in activities that require alertness until you know how the medication affects you.
• Alcohol and Other Central Nervous System Depressants: Avoid consuming alcohol or using other medications that have central nervous system depressant effects while taking dextromethorphan and quinidine, as they may increase the risk of drowsiness, dizziness, or impaired coordination.
• Monitoring: Your healthcare provider may need to monitor your heart function, especially if you have a history of heart problems, while taking quinidine.
• Overdose: Taking more than the prescribed dose of dextromethorphan and quinidine can lead to serious side effects, including overdose. Seek immediate medical attention if you suspect an overdose or experience symptoms such as confusion, hallucinations, rapid heart rate, severe drowsiness, or difficulty breathing.

Always follow your doctor’s instructions and report any concerning symptoms or side effects promptly. If you have any questions or concerns about dextromethorphan and quinidine, don’t hesitate to discuss them with your healthcare provider.

What special dietary instructions should I follow?

Regarding special dietary instructions, there are no specific dietary restrictions associated with dextromethorphan and quinidine. However, it’s always a good idea to maintain a balanced diet and avoid excessive consumption of alcohol and caffeine, as they may exacerbate certain side effects.

What should I do if I forget a dose?

If you forget to take a dose of dextromethorphan and quinidine, take it as soon as you remember. However, if it’s almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not double the dose to make up for a missed one. If you’re unsure about what to do, consult your healthcare provider or pharmacist for guidance.

What side effects can this medication cause?

Dextromethorphan and quinidine, like any medication, can cause side effects, although not everyone experiences them. Common side effects of dextromethorphan and quinidine may include:

• Dizziness: Feeling lightheaded or unsteady.
• Drowsiness: Experiencing increased sleepiness or fatigue.
• Headache: Pain or discomfort in the head.
• Nausea: Feeling sick to your stomach, sometimes with the urge to vomit.
• Diarrhea: Frequent, loose, or watery bowel movements.
• Abdominal Pain: Discomfort or cramping in the stomach area.
• Fatigue: Feeling unusually tired or lacking energy.
• Dry Mouth: Decreased saliva production, leading to a dry sensation in the mouth.
• Constipation: Difficulty passing stool or infrequent bowel movements.
• Blurred Vision: Visual disturbances or difficulty focusing clearly.
• Insomnia: Difficulty falling asleep or staying asleep.
• Increased Heart Rate: Feeling that your heart is beating faster than usual.
• Urinary Tract Infections: Symptoms such as burning sensation during urination or increased frequency of urination.

Serious side effects of dextromethorphan and quinidine are rare but may include:

• Allergic Reactions: Symptoms such as rash, itching, swelling, severe dizziness, or difficulty breathing.
• Heart Rhythm Changes: Irregular heartbeat or palpitations.
• Seizures: Sudden, uncontrolled electrical disturbances in the brain.
• Serotonin Syndrome: A potentially life-threatening condition characterized by a combination of symptoms such as agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

If you experience any severe or persistent side effects while taking dextromethorphan and quinidine, contact your healthcare provider immediately. It’s essential to report any new or worsening symptoms to ensure appropriate management and monitoring of your condition.

What should I know about storage and disposal of this medication?

When it comes to the storage and disposal of dextromethorphan and quinidine, here are some important points to keep in mind:

• Storage: Store the medication at room temperature away from light and moisture. Avoid storing it in the bathroom or kitchen where it could be exposed to heat and humidity. Keep it out of reach of children and pets.
• Disposal: Dispose of any unused or expired medication properly according to local regulations. Do not flush medications down the toilet or pour them down the drain unless instructed to do so. Consult your pharmacist or local waste disposal company for guidance on the safe disposal of medication.

In case of emergency/overdose

• Seek Medical Attention: If you suspect an overdose or experience severe symptoms such as confusion, hallucinations, rapid heart rate, difficulty breathing, or loss of consciousness, seek immediate medical attention. Call your local emergency services or go to the nearest emergency room.
• Poison Control Center: You can also contact your local poison control center or the national poison hotline for guidance on what to do in case of an overdose. They can provide information on first aid measures and connect you with medical professionals for further assistance.

What other information should I know?

• Regular Monitoring: Your healthcare provider may periodically monitor your heart rhythm and overall health while you are taking dextromethorphan and quinidine to ensure that the medication is working effectively and not causing any adverse effects.
• Follow-up Appointments: Attend all scheduled follow-up appointments with your doctor to discuss your progress, any side effects or concerns you may have, and any adjustments that may be needed to your treatment plan.
• Interactions: Be aware of potential drug interactions with other medications, supplements, or herbal products. Inform your healthcare provider about all the medications you are taking to avoid any harmful interactions.
• Patient Education: Make sure you understand how to take dextromethorphan and quinidine correctly, including dosing instructions, potential side effects, and what to do if you miss a dose or overdose.

By being informed and following these guidelines, you can safely and effectively use dextromethorphan and quinidine as prescribed by your healthcare provider.