Usage
Chlorpheniramine Maleate + Diethylcarbamazine is prescribed for the treatment of certain parasitic worm infections, most notably lymphatic filariasis (also known as elephantiasis) caused by Wuchereria bancrofti, Brugia malayi, or Brugia timori. It is also used for loiasis (caused by Loa loa), Mansonella streptocerca infections, tropical pulmonary eosinophilia, and visceral larva migrans.
This combination medication falls under the pharmacological classification of antiparasitic and antihistamine.
The diethylcarbamazine component works by immobilizing and disrupting the metabolism of the microfilariae (larval stage of the parasite), making them susceptible to the host’s immune system. Chlorpheniramine, an antihistamine, mitigates the allergic reactions (itching, swelling, hives) that can occur when the parasites die and release inflammatory substances.
Alternate Names
There are no widely recognized alternate generic names for this combination. However, numerous brand names exist depending on the manufacturer and geographical region. Some examples include DC Forte, Unicarbazan Forte, and Dec Tablet.
How It Works
Pharmacodynamics: Diethylcarbamazine affects the parasites by altering their outer membrane and decreasing their muscular activity, leading to paralysis and death. Chlorpheniramine acts as an H1-receptor antagonist, blocking the effects of histamine, a chemical mediator responsible for allergic symptoms.
Pharmacokinetics: Diethylcarbamazine is well-absorbed orally and widely distributed in the body. It is metabolized in the liver and primarily excreted in the urine. Chlorpheniramine is also absorbed well orally, metabolized in the liver by CYP enzymes, and excreted in the urine.
Mode of Action: Diethylcarbamazine disrupts the worm’s metabolic processes, making it more susceptible to attack by the host’s immune system. It may also inhibit arachidonic acid metabolism in the parasite. Chlorpheniramine competitively binds to H1 histamine receptors, preventing histamine from binding and eliciting its effects.
Elimination Pathways: Both drugs are primarily eliminated through renal excretion following hepatic metabolism.
Dosage
Standard Dosage
Adults:
The typical dosage for filariasis, loiasis, and river blindness is 2-3 mg/kg of body weight three times daily, taken after meals. For tropical pulmonary eosinophilia, the dosage is 6 mg/kg daily, divided into three doses, for 14 days. For visceral larva migrans, it is 6 mg/kg daily, divided into three doses, for 7-10 days.
Children:
Pediatric dosage is usually based on weight, starting at 1 mg/kg on the first day and gradually increasing to 6 mg/kg daily, divided into three doses.
Special Cases:
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Elderly Patients: Caution is advised due to potential age-related decrease in renal and hepatic function. Dose adjustment may be necessary.
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Patients with Renal Impairment: Dose reduction may be required in patients with significant renal dysfunction.
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Patients with Hepatic Dysfunction: Caution is advised. Dose adjustment might be needed.
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Patients with Comorbid Conditions: Caution is warranted in patients with asthma, glaucoma, urinary retention, or an enlarged prostate.
Clinical Use Cases
Dosage for specific medical settings is not specifically outlined in the sources. Dosage is usually determined by the type and severity of the parasitic infection.
Dosage Adjustments
Dose modifications are based on patient-specific factors, including renal and hepatic function. Patients with impaired renal function typically require a dose reduction.
Side Effects
Common Side Effects:
Nausea, vomiting, loss of appetite, headache, drowsiness, dizziness, dry mouth, blurred vision, and allergic reactions (rash, itching, swelling).
Rare but Serious Side Effects:
Severe allergic reactions (anaphylaxis), seizures, encephalopathy, and ocular complications (night blindness, vision loss).
Long-Term Effects:
Long-term use, especially in high doses, can potentially cause vision problems. Regular eye check-ups are advised during prolonged therapy.
Adverse Drug Reactions (ADR):
Severe allergic reactions, including anaphylaxis, require immediate medical attention.
Contraindications
Hypersensitivity to diethylcarbamazine or chlorpheniramine, asthma, and severe renal impairment.
Drug Interactions
Antihistamines (including topical antihistamines), CNS depressants (alcohol, opioids, sedatives, muscle relaxants), and certain antidepressants.
Pregnancy and Breastfeeding
The safety during pregnancy and breastfeeding has not been definitively established. The potential benefits must be weighed against the potential risks. It is generally advisable to avoid using this medication during pregnancy unless the benefits clearly outweigh the risks, as per the doctor’s advice. Use with caution during breastfeeding as it may pass into breast milk.
Drug Profile Summary
- Mechanism of Action: Diethylcarbamazine: Antiparasitic; Chlorpheniramine: Antihistamine (H1-receptor antagonist).
- Side Effects: Nausea, drowsiness, dizziness, dry mouth, allergic reactions.
- Contraindications: Hypersensitivity, asthma, severe renal impairment.
- Drug Interactions: Other antihistamines, CNS depressants, some antidepressants.
- Pregnancy & Breastfeeding: Use with caution. Consult a physician.
- Dosage: Varies based on infection type and patient factors.
- Monitoring Parameters: Renal and hepatic function, ocular health.
Popular Combinations
This drug itself is a combination. It is not usually combined with other drugs aside from those prescribed to manage side effects (e.g. antiemetics for nausea).
Precautions
- General Precautions: Assess for allergies, renal/hepatic function, and other medical conditions before initiating therapy.
- Specific Populations: Use cautiously in pregnant/breastfeeding women, children, and the elderly.
- Lifestyle Considerations: Avoid alcohol as it may increase drowsiness. Avoid driving or operating machinery if experiencing drowsiness or dizziness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Chlorpheniramine Maleate + Diethylcarbamazine?
A: The dosage varies based on the infection being treated. Consult a doctor for specific dosing instructions.
Q2: What are the common side effects?
A: Common side effects include nausea, headache, drowsiness, dizziness, dry mouth, and allergic reactions.
Q3: Can this medication be used during pregnancy?
A: It’s generally avoided during pregnancy unless the benefits outweigh the risks. Consult a doctor.
Q4: Is it safe to breastfeed while taking this medicine?
A: This medication may pass into breast milk. Consult with a doctor about potential risks and alternative therapies.
Q5: Are there any drug interactions I should be aware of?
A: Yes, it can interact with other antihistamines, CNS depressants (e.g., alcohol, opioids), and certain antidepressants. Inform your physician about all medications you are taking.
Q6: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember, unless it is almost time for your next dose. Do not double the dose to catch up.
Q7: Are there any long-term side effects associated with this medication?
A: Prolonged use, especially at high doses, can potentially cause vision problems. Regular eye check-ups are advised.
Q8: What are the contraindications for using this drug?
A: Contraindications include hypersensitivity to the components, asthma, and severe renal impairment.
Q9: How does this medication work against parasitic infections?
A: Diethylcarbamazine immobilizes the microfilariae and disrupts their metabolism, making them susceptible to the host’s immune system. Chlorpheniramine manages the allergic reactions that may occur when parasites die.
