diethylcarbamazine

Diethylcarbamazine belongs to a class of medications known as anthelmintics used to treat filarial diseases caused by parasitic worm infections. Filarial diseases are caused by the larvae of microscopic thread-like worms (filariae) which are transmitted through the bites of blood-feeding insects such as mosquitos, midges and flies. The worm larvae (microfilariae) enter the body, become adult worms and infest various tissues including the lymphatic system, skin, eyes, liver, lung, chest and abdominal cavities.

The exact mechanism by which diethylcarbamazine kills the filariae and microfilariae is not clear. Diethylcarbamazine is believed to immobilize the worm’s muscles and alter its skin membranes, enhancing the host immune system’s ability to kill the worms. Some of the drug reactions are likely the result of the inflammatory response of the immune system and the intensity of the reactions may be related to the intensity of the infection.

Filarial infections are prevalent in tropical regions where these worms are more commonly found. Diethylcarbamazine is no longer approved by the Food and Drug Administration (FDA) and is not commercially available in the U.S., because these types of infections are rare in the U.S.

Diethylcarbamazine is available from the Centers for Disease Control (CDC) Drug Service for patients via an investigational new drug (IND) protocol for treatment of certain filarial diseases and for prophylactic use in persons at increased risk for loiasis.

Diethylcarbamazine is used to prevent and treat the following conditions:

• Lymphatic filariasis which affects the lymphatic system caused by infection with Wuchereria bancrofti, Brugia malayi, or Brugia timori
• Tropical pulmonary eosinophilia, caused when the above filariae enter the lungs
• Loiasis caused by Loa loa, also known as the eye worm
• Streptocerciasis caused by infection with Mansonella streptocerca
• Visceral larva migrans, also known as toxocariasis, caused by roundworms found in the intestines of dogs and cats (Toxocara canis and T. cati)

• Do not use in patients with hypersensitivity to diethylcarbamazine or any of its components
• Do not use diethylcarbamazine to treat patients who have onchocerciasis, also known as river blindness, which is caused by the parasite Onchocerca volvulus; can result in a severe potentially life-threatening allergic response known as Mazzotti reaction with symptoms including rashes and itching, fever, rapid heartbeat (tachycardia) and low blood pressure (hypotension)
• Brain damage (encephalopathy) and severe neurologic adverse reactions have been reported in the treatment of loiasis with high microfilarial load; microfilarial load should be reduced through blood filtering procedure (apheresis) or treatment with albendazole before initiating diethylcarbamazine
• Some symptoms of loiasis such as Calabar swelling and itching may increase briefly during treatment; using antihistamines and corticosteroids simultaneously during the first week of treatment may decrease these symptoms
• Use with caution in patients with cardiac disorders
• Use with caution in patients with renal impairment; dosage reduction recommended
• Diethylcarbamazine excretion is lower in alkaline urine; dose reduction may be required in patients on diets that promote alkalinization of the urine

Side effects of diethylcarbamazine include:

• Dizziness
• Headache
• Fever
• Joint pain (arthralgia)
• Muscle pain (myalgia)
• Nausea
• Vomiting

Less common side effects of diethylcarbamazine include:

• Abdominal pain
• Decreased appetite
• Diarrhea
• Cardiovascular collapse
• Drop in blood pressure when standing up from sitting or lying down (orthostatic hypotension)
• Rapid heart rate (tachycardia)
• Skin reactions including:
  • Dermatitis
  • Itching
  • Urticaria
  • Skin edema
• Asthma
• Respiratory distress
• Drowsiness
• Vertigo
• Fatigue
• Lethargy
• Feeling unwell (malaise)
• Fever
• Brain disease
• Coma
• Worm infection in the brain (helminthic meningoencephalitis)
• Allergic brain inflammation (encephalitis)
• Swelling of glands (adenitis)
• Excessive protein in the urine (proteinuria)
• Swelling of lymph nodes from infection (lymphadenitis)
• Infection of lymph channels (lymphangitis)
• Seizure in patients with a history of epilepsy (rare)

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug.

Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Tablet

• 100 mg

Adult:

Filarial Diseases

• Day 1: 50 mg orally after meals
• Day 2: 50 mg orally three times daily
• Day 3: 100 mg orally three times daily
• Day 4-14: 6 mg/kg/day orally divided three times daily

Loiasis

• Day 1: 50 mg orally after meals
• Day 2: 50 mg orally three times daily
• Day 3: 100 mg orally three times daily
• Day 4-21: 9 mg/kg/day orally divided three times daily

Streptocerciasis

• 6 mg/kg orally once daily for 14 days

Adult and pediatric:

Tropical Pulmonary Eosinophilia

• 6 mg/kg/day divided three times daily for 14 days

Visceral Larva Migrans

• 6 mg/kg/day orally divided three times daily for 7-10 days

Pediatric:

Filarial diseases

• Day 1: 1 mg/kg orally after meals
• Day 2: 1 mg/kg orally three times daily
• Day 3: 1-2 mg/kg orally three times daily
• Day 4-14: 6 mg/kg/day orally divided three times daily

Loiasis

• Day 1: 1 mg/kg orally after meals
• Day 2: 1 mg/kg orally three times daily
• Day 3: 1-2 mg/kg orally three times daily
• Day 4-21: 9 mg/kg/day orally divided three times daily

• Seek immediate medical help or contact Poison Control in case of overdose.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Diethylcarbamazine has no listed severe interactions with other drugs.
• Diethylcarbamazine has no listed serious interactions with other drugs.
• Diethylcarbamazine has moderate interactions with at least 71 different drugs.
• Diethylcarbamazine has mild interactions with at least 101 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• Do not use diethylcarbamazine during pregnancy
• Avoid exposure to infection and avoid travel to infected areas during pregnancy
• Maternal filarial infection can be transmitted to the fetus, eradicate infection prior to pregnancy or institute treatment after delivery
• It is not known if diethylcarbamazine is present in breast milk; avoid use while breastfeeding

• Diethylcarbamazine is not commercially available in the U.S.
• To obtain, contact the CDC at 404-718-4745 or email [email protected] or visit https://www.cdc.gov/laboratory/drugservice/formulary.html.