Anyone suffering from worm disease cannot avoid diethylcarbamazine. In fact, the active ingredient is so important that it has been added to the list of essential medicines by the WHO (World Health Organization). This is not surprising, since a good 200,000 people still die from worm diseases every year.
What is diethylcarbamazine?
Diethylcarbamazine is effective against certain types of parasitic worm infestation and is therefore classified as an anthelmintic. Diethylcarbamazine is chemically a piperazine derivative. It is effective against certain types of parasitic worm infestation and is therefore classified as an anthelmintic. It is always administered as a citrate. Diethylcarbamazine citrate is a white crystalline powder with a melting point of about 138 °C. It is very soluble in water. It is very soluble in water, but only slightly soluble in alcohol (1 g in 35 ml). It absorbs atmospheric moisture relatively quickly. The active ingredient was first patented in 1949 by the American Cyanamid company. Diethylcarbamazine circulates under the trade names Hetrazan, Carbilazine, Caricide, Cypip, Ethodryl, Notézine, Spatonin, Filaribits and Banocide Forte. The usual dosage forms are tablets of 50 mg or suspensions of 24 g/ml.
Pharmacologic Action
Diethylcarbamazine is almost completely absorbed through the intestine after oral ingestion and is distributed to all body regions except adipose tissues. The maximum blood concentration is present after 1-2 hours. How the molecule acts against the worms is not fully understood; one assumption is that diethylcarbamazine acts similarly to nicotine on the central nervous system of the parasites, thereby paralyzing them. Furthermore, it is assumed that the surface structure of the worms is changed so that the body’s own phagocytes can recognize and eliminate them more easily. The active ingredient is rapidly processed and excreted mainly through the kidneys. In the first 24 hours after ingestion, 70% of the dose is already detected in the urine, of which 10-25% is in unchanged form.
Medical use and application
In principle, diethylcarbamazine can only be used against certain types of worms. These are so-called filariae, which belong to the group of threadworms (nematodes). These parasites infest humans as hosts, but do not reproduce in them – this is referred to as infestation. The largest area of application is loiasis, a tropical worm disease of humans caused by the filarial Loa loa. According to WHO estimates, approximately 13 million people are infected worldwide. Diethylcarbamazine can be used here both in temporary prevention (prophylaxis) and in treatment. The drug was also of interest to dog owners because it is effective against early larval stages of Dirofilaria immitis. This nematode is transmitted by mosquitoes and infects the dog’s heart, where the 20-30 cm long adult (adult) heartworms develop. In the meantime, however, diethylcarbamazine-based preparations are no longer approved for use in animals in Germany. In onchocerciasis, efficacy has been described only against microfilariae, the very early larval stages of the nematodes. The disease occurs in tropical areas of Africa and the Americas and is caused by filariae of the species Onchocerca volvulus. In about 10% of cases, it leads to blindness, known as river blindness. The WHO recommends, among other things, the administration of diethylcarbamazine in combination with praziquantel to combat worm infections in humans. This makes it possible to cover a broad spectrum of worms – which is so important because it is often not possible to determine the exact pathogen or pathogens. Diethylcarbamazine is not given in cases of restricted kidneys (renal insufficiency) and urinary alkalosis.
Risks and side effects
Characteristic side effects of diethylcarbamazine are disturbances and overreactions of the immune system, which are particularly common in the treatment of onchocerciasis. These include itching, fever, and severe headache. Other side effects include nausea, vomiting, feeling of pressure in the abdomen, dizziness and fatigue. Shortness of breath, cough, accelerated heartbeat (tachycardia), and proteinuria (increased protein excretion through the urine) have also been reported. All of these symptoms can be explained by the skyrocketing concentration of toxic waste products from killing and decomposing the worms.Side effects occur a few hours after administration but usually disappear after about five days.
