Usage
- This combination medication is primarily prescribed for certain parasitic worm infections, such as filariasis (including lymphatic filariasis and loiasis) and tropical pulmonary eosinophilia. It may also be used to treat symptoms associated with these infections, such as cough, breathlessness, and allergic reactions like itching, swelling, and skin rash.
- Pharmacological Classification: Antiparasitic, antihistamine, and expectorant.
- Mechanism of Action: Diethylcarbamazine is an antiparasitic that immobilizes and kills microfilariae (immature worms) and some adult worms. Chlorpheniramine is an antihistamine that blocks the effects of histamine, reducing allergic symptoms. Guaifenesin is an expectorant that thins and loosens mucus, making it easier to cough up.
Alternate Names
- While there isn’t a universally recognized alternate name for this specific three-drug combination, each component has its own alternate names. Diethylcarbamazine is sometimes referred to as DEC. Chlorpheniramine is available as chlorpheniramine maleate or chlorpheniramine base. Guaifenesin is also known as glyceryl guaiacolate.
- Brand Names: This combination is available under various brand names like “Dec” in some regions. Brand names can vary considerably depending on the manufacturer and country.
How It Works
- Pharmacodynamics: Diethylcarbamazine immobilizes microfilariae, making them susceptible to the body’s immune system. Chlorpheniramine antagonizes the H1 histamine receptor, relieving allergic symptoms. Guaifenesin increases respiratory tract fluid secretions, reducing mucus viscosity.
- Pharmacokinetics: Diethylcarbamazine is well-absorbed orally, metabolized in the liver, and excreted mainly in the urine. Chlorpheniramine is also well-absorbed orally, metabolized in the liver, and excreted in the urine. Guaifenesin is readily absorbed orally and primarily excreted unchanged in the urine.
- Mode of Action: Diethylcarbamazine’s exact mechanism against adult worms isn’t fully clear, but it’s thought to affect arachidonic acid metabolism. Chlorpheniramine competitively inhibits histamine at H1 receptors. Guaifenesin likely breaks disulfide bonds in mucus glycoproteins.
- Elimination Pathways: Primarily renal excretion for all three components. Hepatic metabolism plays a role in the elimination of diethylcarbamazine and chlorpheniramine.
Dosage
Standard Dosage
Adults:
Dosage is determined by the doctor based on body weight and the specific infection. A common dosage regimen is 2 to 3 mg of diethylcarbamazine per kilogram of body weight three times a day, often given in combination with fixed doses of chlorpheniramine and guaifenesin.
Children:
Dosage needs to be determined by a doctor. This combination is generally not recommended for young children. Some formulations may be appropriate for children over 2 years old, with careful dose adjustments based on weight and age.
Special Cases:
- Elderly Patients: Dose reduction may be necessary due to potential age-related decline in liver and kidney function.
- Patients with Renal Impairment: Dose adjustments should be based on the degree of impairment.
- Patients with Hepatic Dysfunction: Dose modifications are usually necessary for impaired liver function.
- Patients with Comorbid Conditions: Careful consideration of potential drug interactions is necessary for patients with conditions like cardiovascular disease, glaucoma, or asthma.
Clinical Use Cases
The dosage for this combination is not typically adjusted for specific clinical scenarios like intubation, surgery, or ICU use. It’s primarily used for the treatment of parasitic infections, and the dosage is based on the infection’s severity and the patient’s individual characteristics.
Dosage Adjustments
Dose modifications are based on factors such as renal/hepatic impairment and patient response. Close monitoring is important, especially during prolonged therapy.
Side Effects
Common Side Effects
Nausea, vomiting, headache, dizziness, drowsiness, loss of appetite, allergic reactions (skin rash, itching).
Rare but Serious Side Effects
Severe allergic reactions, vision changes (blurred vision, night blindness), encephalopathy (in patients with Loa Loa infection).
Long-Term Effects
With prolonged use, vision changes can occur. Regular eye checkups are recommended during extended treatment.
Adverse Drug Reactions (ADR)
Severe allergic reactions (anaphylaxis, angioedema) require immediate medical attention.
Contraindications
Hypersensitivity to any component, severe asthma, concomitant use of MAO inhibitors, gastrointestinal obstruction, urinary retention, narrow-angle glaucoma, pregnancy (unless benefits outweigh risks), breastfeeding (unless benefits outweigh risks), young children.
Drug Interactions
Antihistamines (additive sedative effects), alcohol (increased drowsiness), CNS depressants (increased CNS depression), MAO inhibitors (hypertensive crisis risk), certain antidepressants, anticonvulsants, and narcotic analgesics.
Pregnancy and Breastfeeding
This combination should generally be avoided during pregnancy and breastfeeding unless the potential benefit clearly outweighs the risks. If use is deemed necessary, close monitoring of both mother and child is essential. Safer alternative treatments should be considered whenever possible.
Drug Profile Summary
- Mechanism of Action: Diethylcarbamazine (antiparasitic), chlorpheniramine (antihistamine), guaifenesin (expectorant).
- Side Effects: Drowsiness, dizziness, dry mouth, nausea, headache, allergic reactions.
- Contraindications: Hypersensitivity, severe asthma, MAO inhibitor use, pregnancy, breastfeeding.
- Drug Interactions: Other antihistamines, alcohol, CNS depressants, MAO inhibitors.
- Pregnancy & Breastfeeding: Use with extreme caution only if clearly necessary.
- Dosage: Determined by the doctor based on patient’s weight, age and specific infection.
- Monitoring Parameters: Eye exams, liver function, kidney function (especially with long-term use).
Popular Combinations
Diethylcarbamazine is sometimes combined with albendazole or ivermectin for specific parasitic infections, but generally not in a fixed combination with chlorpheniramine and guaifenesin.
Precautions
Assess renal and hepatic function before initiating therapy. Avoid alcohol during treatment. Monitor for vision changes. Use cautiously in patients with asthma, glaucoma, or prostatic hypertrophy.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Chlorpheniramine Maleate + Diethylcarbamazine + Guaifenesin?
A: The dosage is determined by the prescribing doctor based on the individual patient’s weight and the specific parasitic infection being treated. There’s no fixed, universal dosage.
Q2: Can this combination be used in children?
A: It’s generally not recommended for young children, but some formulations may be suitable for older children with careful dose adjustments. Consult a pediatrician for appropriate guidance.
Q3: Is it safe to take this medication during pregnancy or while breastfeeding?
A: This combination is typically avoided during pregnancy and breastfeeding unless potential benefits clearly outweigh the risks. Discuss alternative treatments with your doctor.
Q4: What are the most common side effects?
A: Common side effects include nausea, headache, dizziness, drowsiness, and allergic reactions.
Q5: Are there any serious side effects to be aware of?
A: Yes, severe allergic reactions and vision changes are possible. Encephalopathy can occur in patients with loiasis.
Q6: Can I consume alcohol while taking this medication?
A: Alcohol should be avoided, as it can exacerbate the sedative effects of this combination.
Q7: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember, unless it’s close to your next scheduled dose. Do not double the dose.
Q8: Are there any specific monitoring parameters for this medication?
A: Yes, regular eye exams are recommended for patients on prolonged therapy. Liver and kidney function should also be monitored as needed.
Q9: What should I tell my doctor before starting this medication?
A: Inform your doctor about any other medications you are taking, any allergies you have, and any pre-existing medical conditions, especially asthma, glaucoma, or liver/kidney problems.
Q10: How should I store this medication?
A: Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
