Diethylcarbamazine is an antihelminthic drug that is used in the treatment of filariasis, tropical pulmonary eosinophilia, and loasis. It is also used in the treatment of patients with river blindness, however, ivermectin is preferred.

Diethylcarbamazine Uses:

• Loiasis:
  • Treatment and prophylaxis of loiasis caused by Loa loa.
• Lymphatic filariasis:
  • Treatment of lymphatic filariasis caused by Wuchereria bancrofti, Brugia malayi, or Brugia timori

Diethylcarbamazine Dosage in Adults:

Note:

• Dosages mentioned as diethylcarbamazine citrate;
• some products may express dosing according to diethylcarbamazine (base).
• The ratio of diethylcarbamazine citrate to diethylcarbamazine (base) is almost 2:1.

Diethylcarbamazine Dose in the treatment of Loiasis:

• Treatment:
  • CDC recommendations:
    • 8 to 10 mg/kg/day in three divided doses for 21 days;
    • patients with symptomatic loiasis and microfilarial loads ≥8,000 microfilariae/mL should receive apheresis or treatment with albendazole prior to treatment with diethylcarbamazine (CDC 2015).
    • For patients with microfilaria in the blood, some physicians recommend the following regimen:
      • • 50 mg as a single dose on day 1;
        • 50 mg 3 times daily on day 2;
        • 100 mg 3 times daily on day 3;
        • 9 mg/kg/day in 3 divided doses on day 4 to end of the treatment course.
        • Repeat courses of treatment may be needed to achieve a cure.
  • WHO recommendations:
    • Initial: 1 mg/kg as a single dose on day 1,
    • doubling of the dose on the next 2 days,
    • then 6 to 9 mg/kg/day in divided doses 3 times daily for 18 days.
• Prophylaxis:
  • 300 mg once weekly; continue as long as exposure occurs.

Diethylcarbamazine Dose in the treatment of Lymphatic filariasis:

• CDC recommendations:
  • 6 mg/kg/day orally as a single dose or 6 mg/kg/day in 3 divided doses for 12 days (14 to 21 days in patients with tropical pulmonary eosinophilia).
  • For patients with microfilaria in the blood, some Physicians recommend the following dose-escalating regimen:
    • 50 mg as a single dose on day 1;
    • 50 mg 3 times daily on day 2;
    • 100 mg 3 times daily on day 3;
    • 6 mg/kg/day in 3 divided doses on day 4 to end of treatment course.
• WHO recommendations:
  • Due to W. bancrofti:
    • Initial: 1 mg/kg as a single dose on day 1;
    • increase gradually over 3 days to 6 mg/kg/day, in 3 divided doses for 12 days.
  • Due to B. malayi or B. timori:
    • 1 mg/kg as a single dose on day 1;
    • increase gradually over 3 days to 3 to 6 mg/kg/day, in 3 divided doses for 6 to 12 days.

Diethylcarbamazine dosage in children:

Note:

• Dosages mentioned as diethylcarbamazine citrate;
• some products may mention dosing according to diethylcarbamazine (base).
• The ratio of diethylcarbamazine citrate to diethylcarbamazine (base) is almost 2:1.

Diethylcarbamazine Dose in the treatment of Loiasis:

• Children and Adolescents:
  • 8 to 10 mg/kg/day orally in three divided doses for 21 days;
  • patients with symptomatic loiasis and microfilarial loads ≥8,000 microfilariae/mL should undergo apheresis or treatment with albendazole before getting treatment with diethylcarbamazine.
  • For patients with microfilaria in the blood, some physicians recommend starting with a lower dosage (eg, 50 mg/day) with a gradual increase over 3 days to 9 mg/kg/day in 3 divided doses on day 4 to end of treatment course.

Diethylcarbamazine Dose in the treatment of Lymphatic filariasis:

• CDC recommendations:
  • Children ≥18 months and Adolescents:
    • 6 mg/kg/day as a single dose or 6 mg/kg/day in 3 divided doses for 12 days (14 to 21 days in patients with tropical pulmonary eosinophilia).
    • For patients with microfilaria in the blood, some clinicians recommend starting with a lower dosage (eg 50 mg/day) with a gradual increase over 3 days to 6 mg/kg/day in 3 divided doses on day 4 to end of the treatment course.
• WHO recommendations:
  • Children >10 years and Adolescents:
    • Refer to adult dosing.

Pregnancy Risk Category: X

• Pregnancy is not a good time to use diethylcarbamazine.
• Filarial infections (W. bancrofti and Loa loa), can be passed from mother to baby during pregnancy.
• It is important to eliminate maternal infections before conception and delay treatment until after birth.
• Women who are pregnant should not travel to infected regions.

Use of diethylcarbamazine during breastfeeding

• Breastfeeding is not recommended because it is not known whether diethylcarbamazine may be present in breast milk.

Dose in Kidney Disease:

• Dose reduction in moderate to severe impairment (no specific adjustment is provided).

Diethylcarbamazine Dose adjustment in patients with liver disease:

No dosage adjustments have been mentioned, however, use with caution in advanced liver disease.   

Side effects of Diethylcarbamazine:

In patients with circulating microfilaremia, adverse reactions may be more common and severe, particular in patients with a high parasite burden.

• Cardiovascular:
  • Collapse
  • Orthostatic Hypotension
  • Tachycardia
• Central Nervous System:
  • Brain Disease
  • Coma
  • Dizziness
  • Drowsiness
  • Encephalitis (Allergic)
  • Fatigue
  • Headache
  • Lethargy
  • Malaise
  • Meningoencephalitis (Helminthic)
  • Vertigo
• Dermatologic:
  • Dermatitis
  • Mazzotti Reaction
  • Pruritus
  • Urticaria
• Endocrine & Metabolic:
  • Adenitis
• Gastrointestinal:
  • Abdominal Pain
  • Decreased Appetite
  • Diarrhea
  • Nausea
  • Vomiting
• Genitourinary:
  • Proteinuria (May Be Reversible)
• Hematologic & Oncologic:
  • Lymphadenitis
  • Lymphangitis
• Local:
  • Skin Edema
• Neuromuscular & Skeletal:
  • Arthralgia
  • Myalgia
• Ophthalmic:
  • Conjunctivitis
  • Corneal Edema
  • Eye Disease (Inflammatory And Degenerative Changes Of Optic Nerve Retina With Prolonged Use)
  • Eye Pain
  • Increased Intraocular Pressure
  • Iridocyclitis
  • Lacrimation
  • Optic Neuritis
  • Photophobia
  • Punctate Keratitis
  • Visual Field Defect
• Respiratory:
  • Asthma
  • Respiratory Distress
• Miscellaneous:
  • Fever

Contraindications to Diethylcarbamazine:

• Patients with onchocerciasis.

Warnings and Precautions

• Encephalopathy:
  • Loiasis can be treated with encephalopathy, which can sometimes prove fatal.
  • Risk is linked to microfilarial loads. Before treatment, it is important to check the microfilarial load.
  • Be cautious if your microfilarial load is greater than 2,500 microfilariae/mL
  • Before starting treatment with diethylcarbamazine, patients with microfilarial loads greater than 8,000 microfilariae/mL need to have their load reduced by apheresis and treatment with albendazole.
  • The risk of fatal encephalopathy is not reduced by corticosteroid use or slow dose escalation.
• Inflammatory reactions
  • Patients with onchocerciasis can experience a Mazzotti reaction (pruritus and fever, arthralgia).
  • Permanent visual damage can be caused by inflammation in the retina and cornea.
  • Patients with onchocerciasis should not use this medication.
  • Before starting treatment with diethylcarbamazine, it is important to rule out the possibility of co-infection.
• Reactions to skin:
  • Some symptoms of loiasis may temporarily increase in patients being treated for it.
  • These symptoms may be reduced if you take antihistamines or corticosteroids in the first week.
• Cardiac disorders:
  • Patients with heart problems should be cautious.
• Renal impairment
  • Take care; you should reduce the dosage.

Monitoring parameters:

• Renal function at baseline and periodically during treatment;
• in patients with loiasis, measure microfilarial load prior to treatment;
• patients with microfilarial loads ≥8,000 microfilariae/mL treated with albendazole to reduce microfilarial load should have close, frequent monitoring of microfilarial load to confirm reduction before initiation of treatment with diethylcarbamazine.  

How to administer Diethylcarbamazine?

Oral: Administer after meals.   

Mechanism of action of Diethylcarbamazine:

• It is not known what the exact mechanism of action is.
• Some of the proposed mechanisms are
  • Microfilariae are triggered by platelet activation of the release of excretory Antigen through microfilariae
  • Modifications in prostaglandin metabolism of microfilariae and host cells that lead to immobilization through inhibition of parasite-cholinergic muscular receptors
  • Disruption of microtubule production
  • These include alterations to the helminth's surface membranes, which can lead to an increase in killing by the host immune.

Absorption:

• Well absorbed.

Protein binding:

• Not significant.

Half-life elimination:

• 10 to 12 hours.

Time to peak:

• 1 to 2 hours.

Excretion:

• Urine (~50% as unchanged drug; ~10% as metabolite);
• feces (~10%)

International Brands of Diethylcarbamazine:

• Banocide
• Camin
• DCMC
• Decet
• Dicarmin
• Dicazin
• Diethizine
• Eofil
• Filadec
• Filarizide
• Hetrazan
• Noterine
• Notezine
• Remazin

Diethylcarbamazine Brand Names in Pakistan:

No Brands Available in Pakistan.