Terminating a helminth infection
This page addresses the termination of the four species of helminth used in helminthic therapy. The eradication of other organisms requires different species-specific drugs and dosing regimes. [1]
The efficacy of anthelmintic (antihelminthic) treatment depends on the drug used, the dosing regimen and the timing of doses in relation to food. It may also depend on the host's microbiome profile. [2] Even the most effective anthelmintic can fail to kill every last worm, but the efficacy rates for anthelmintic drugs used in developed countries are likely to be higher than some of those quoted below, which may have been taken from studies carried out in less developed areas, where mass deworming programmes have led to the development of drug resistance.
Availability of anthelmintic drugs
The availability of anthelmintic drugs varies between countries. For example, albendazole is available with a prescription in Europe [3] but not available on prescription in the US or UK. Also, where this drug is prescribed "off-label", the cost can be astronomical, e.g., as much as US$ 700 per tablet. [4][5]
However, mebendazole, albendazole and pyrantel pamoate are all used to treat both hookworm infection and Enterobius vermicularis (EV) infection (pinworm' in the US, and 'threadworm' in the UK and Australia), and at least one of these drugs is generally available over-the-counter in Western countries to treat EV, which is very common in children. For example mebendazole is available OTC in the UK, and pyrantel in the US. If a pharmacist is asked for medication to treat a family whose members have all contracted EV, there will be plenty to eradicate a hookworm infection. See the dosage details here:
Alternatively, albendazole and other anthelmintics can be obtained online from a number of suppliers including the following.
- Mark Cuban Cost Plus Drug Company (US-based) Everything is sold at cost plus 15%.
- United Pharmacies (US-based)
- AllDayChemist (Japan-based) 12 x 400mg albendazole was US$ 13.50 in March 2023, but delivery can be slow.
The service (of AllDayChemist) is good. The main downside is that shipping time--to me in the US--seems extremely long. One month is not unusual. [6]
- Medsmex (Mexico-based) 2 x 200mg albendazole were $16.73 in March 2023.) Shipments may take a month to reach some US addresses. [7]
However, customs departments in some European countries may block shipments from outside the EU. [8]
Another source of anthelmintics is veterinary medications, which are often available without a prescription. [9] Care must obviously be taken with dosing when using veterinary products in humans because of the much larger body weight of many farm animals, but dosing recommendations for products that are tailored for sheep can arguably provide a reasonable guide due to the similarity of body weight between sheep and humans. [10] For example, see the dosage for sheep for this product.
Terminating a human hookworm (NA) infection
Current CDC recommendations
Here is the current advice from the United States Centers for Disease Control and Prevention for treating hookworm infections.
Anthelmintic drugs compared
Albendazole was found to be the most effective of five drugs (albendazole, mebendazole, pyrantel pamoate, levamisole and thiabendazole) tested against hookworms (mostly NA) in 1993, [11], and again in 2017. [12] However, the efficacy of frequently used anthelmintic drugs such as albendazole and mebendazole has decreased over time, [13] and, while a single dose of 400 mg albendazole completely cleared infections with the hookworm, Ancylostoma duodenale in 1997, [14] a study reported in 2018 found that a single dose of albendazole (40 mg/kg) only gave a relatively low cure rate against hookworms, calculated at between 66.7% and 79.8%, [15] although this was better than a single dose of 500 mg mebendazole, which only achieved an overall cure rate of 27.6% against hookworms in one study [16] and 30.8% in another study. [17]
A 2019 study found that 400 mg albendazole given daily for three consecutive days achieved a 100% cure rate against hookworms. [18]
A study comparing albendazole with mebendazole [19] found the following cure rates.
- a triple dose of albendazole (1 dose of 400 mg taken each day for 3 consecutive days) ……........ 92%
- a single dose of albendazole (400 mg) …………………………………………………………..................... 70%
- a triple dose of mebendazole (1 dose of 500 mg taken each day for 3 consecutive days) ….................. 58%
- a single dose of mebendazole (500 mg) ……………………………………………………………............... 31%
A 2022 study concluded that, while the standard dose of 400 mg of albendazole is effective in the youngest age groups infected by hookworms, doses of up to 800 mg could further increase albendazole efficacy in hookworm-infected adults. [20]
Factors that may affect success
The timing of treatment in relation to meals can make a significant difference to treatment efficacy.
- The efficacy of albendazole (and possibly other anthelmintics) against hookworms can be enhanced by taking the drug on an empty stomach.
- When a systemic pharmacological effect of albendazole is required, e.g. in echinococcosis, maximal systemic availability is desirable and may be achieved by giving albendazole together with a fatty meal. However, in conditions where low systemic availability and a high intraluminal content of the drug is desirable, as in the treatment of intestinal helminthiasis, the drug should be taken on an empty stomach in order to reduce its absorption. [21]
- When a single dose of 400 mg of albendazole was given to subjects who had not eaten for 6 hours or more prior to treatment, the cure rate for hookworm was raised from 59% to 90%. [22]
Different brands of an anthelmintic drug may have different efficacy rates. [23]
Different forms of tablet containing an anthelmintic drug may have different success rates. For example, chewable tablets may be more effective if they are crushed. [24]
Patient experiences
An NA host who is helminth-permissive (her genetic endowment gives any helminths she hosts a much easier time than they would get in most other people) was able to terminate her hookworm colony by taking 400 mg albendazole each day for four days. Even though the drug was 2 years past its expiration date, she stopped passing hookworm eggs and was unable to incubate more larvae until 12 weeks after reinoculating with 5 larvae from another source.
Alternative anthelmintics
Anything marked with an ❌ on the following page will or may kill, or cause the loss of, human helminths, including hookworms.
Am interesting study of plant extracts seems to indicate several of them are more effective than albendazole. [27]
The timing of re-dosing with hookworms
There may be some advantage in allowing a period of time for the host’s immune system to resettle after the termination of a hookworm colony, but no specific reason to do this has been suggested and, since the biological half-life of albendazole and mebendazole is only 8-12 hours and 3-6 hours respectively, it should be safe to reinoculate 48 hours after completing the course of anthelmintic treatment.
Reducing colony size as an alternative to termination
If termination is being considered to address unmanageable side effects following the addition of too many hookworms, it may not be necessary to terminate the entire colony. Carrying out a partial cull could reduce the severity of the side effects while leaving some worms to continue the therapy.
A partial cull can be achieved by using any of the substances categorised in the Human helminth care manual as being potentially harmful to human helminths (marked with an ❌), although the effects of these substances will not be as predictable as those of an anthelmintic drug.
The details presented in the sections above can be used to tailor a cull to meet the individual self-treater’s particular needs. For example, a single 500mg dose of mebendazole may kill approximately 30% of a colony of NA and, if this doesn't provide sufficient relief from the side effects, further doses of the drug can be taken as required.
Terminating a human whipworm (TT) infection
Current CDC recommendations
Here is the current advice from the United States Centers for Disease Control and Prevention for treating TT infections.
Further information
Single drug doses are ineffective
Single doses of anthelmintics are not very effective against Trichuris trichiura. For example, in one study, a single 500 mg dose of mebendazole only achieved a cure rate of 25.5%. [29] In another trial, a single dose of ivermectin (at 600 mcg/kg) had a cure rate of only 12.2%. [30]
Combining drugs improves efficacy
A head-to-head comparison of single doses of three different drug combinations showed the highest efficacy was achieved by the combination of albendazole and oxantel pamoate. [31]
Drug ........................................................... Cure rate
Albendazole plus oxantel pamoate ……….. 68·5%
Albendazole plus ivermectin …….….…....... 27·5%
Albendazole plus mebendazole ………....….. 8·4%
Mebendazole alone ………………………...… 8·4%
Oxantel pamoate is not universally available, and mebendazole has been found to be marginally more effective against whipworm than albendazole. [32]
Three-day courses are more effective
The US Centers for Disease Control and Prevention (CDC) state that whipworm is effectively treated using albendazole, mebendazole or ivermectin, but that each drug needs to be taken for 3 days. [33]
Drug ............................. Dosage for adults and children
Albendazole .................. 400 mg orally for 3 days
Mebendazole ................ 100 mg orally twice a day for 3 days.
Ivermectin ..................... 200 mcg/kg/day orally for 3 days
While the CDC recommend the use of albendazole and mebendazole, these drugs have been shown to have limited efficacy against T. trichiura, (e.g., albendazole: [34]) and their efficacy is continuing to diminish. [35]
400 mg albendazole, given daily for three consecutive days to children infected with T. trichiura, only achieved a 61% cure rate. [36]
Five-day courses are the most effective
100 mg mebendazole, given twice daily for 5 consecutive days, can effectively terminate a T. trichuria infection. [37]
Terminating a rat tapeworm (HD) infection
Hymenolepis diminuta (HD) is only likely to mature in adult humans who are immunocompromised. Otherwise, the worms will die naturally after approximately 2-3 weeks, so there is rarely any need to deliberately terminate an HD infection in adults.
There is a possibility of HD maturing and persisting in approximately 1% of children, potentially causing gastric pain and/or worsening of behavioural symptoms. In these cases, termination of the infection using an anthelmintic drug will bring about a cessation of symptoms within 1-3 weeks of the drug being administered.
The drugs used to terminate a Hymenolepis infection are described on the following webpage.
Terminating a pig whipworm (TS) infection
Since the porcine whipworm, trichuris suis, only survives in humans for approximately 2-3 weeks, there is little need to deliberately terminate a TS infection. If it were necessary, Wikipedia suggests that this species can be terminated with medicines such as doramectin, ivermectin and febantel.
Terminating suspected pathogenic helminths
If an individual believes that their health is being adversely affected by a pathogenic helminth, they should determine exactly which organism this is by having a DNA polymerase chain reaction (PCR) stool analysis carried out. This can be ordered internationally online from Diagnostic Solutions in Atlanta Georgia, US.
If this test proves positive, the individual should seek treatment using whatever specific agent has been found to be most likely to eradicate that particular organism, rather than use a "parasite cleanse", which is likely to do more harm than good by causing indiscriminate damage to the biome and upsetting the microbiological equilibrium. See Why a parasite cleanse can make you worse.