Humatin: brand name for paromomycin
Humatin is the brand name of paromomycin, an aminoglycoside antibiotic from Streptomyces krestomuceticus. Unlike other aminoglycosides such as gentamicin or amikacin, paromomycin is not absorbed orally and so acts almost exclusively in the intestinal lumen. This property makes it a valuable option for intestinal protozoal infections, particularly intestinal amoebiasis.
Paromomycin has been used in Germany and the US since the 1960s. Beyond amoebiasis it is licensed for hepatic encephalopathy and against some other intestinal parasites. In some countries paromomycin is also used in leishmaniasis, intramuscular or topical.
Mechanism of action
Like all aminoglycosides, paromomycin binds irreversibly to the 30S subunit of the bacterial ribosome. Protein synthesis is disrupted, faulty proteins are produced and the bacterial cell dies. The action is bactericidal.
In protozoa such as Entamoeba histolytica paromomycin interferes with energy metabolism and protein production. The effect is concentrated on the intestinal stages of the parasite; tissue forms are not reached, which is why paromomycin alone is not suitable for invasive amoebiasis (liver abscess).
Because oral paromomycin is barely absorbed (about 1 to 5 %), it reaches high concentrations in the gut and is excreted almost completely with the stool. This explains the favourable safety profile with oral use compared with parenteral aminoglycoside therapy.
Indications
- Intestinal amoebiasis (Entamoeba histolytica): standard for eradication of luminal cysts after invasive disease has been treated with metronidazole
- Asymptomatic cyst carriers: sanitation in family or occupational settings
- Hepatic encephalopathy: reduction of ammonia producing gut bacteria as an alternative to lactulose or rifaximin
- Dientamoeba fragilis and Cryptosporidium: off label in selected cases, with limited efficacy in Cryptosporidium
- Leishmaniasis: intramuscular or topical in endemic areas
- Tapeworm infections (Taenia, Diphyllobothrium): reserve therapy
Dosing and administration
Intestinal amoebiasis: 25 to 35 mg per kg body weight per day, divided into 3 doses, for 5 to 10 days. Adults typically receive 500 mg three times daily.
Hepatic encephalopathy: 1 to 4 g per day, divided into several doses.
Tapeworm infections: single dose according to special protocols.
The drug is taken with meals to reduce gastrointestinal complaints. Because of minimal absorption, paromomycin can be used safely even in renal impairment, provided the gut mucosa is intact.
Adverse effects
Common: gastrointestinal complaints such as nausea, abdominal pain, diarrhoea, cramps, heartburn, loss of appetite.
Uncommon: pruritus, rash, allergic reactions, hearing loss in rare cases.
Rare and very rare: with damaged gut mucosa (ulcers, severe colitis) or with prolonged high dose use, systemic absorption can lead to classical aminoglycoside adverse effects such as nephrotoxicity and ototoxicity.
Important points:
- With intact gut mucosa no relevant systemic adverse effects
- With inflammatory bowel disease or ulcers, increased absorption with possible toxicity
- Pseudomembranous colitis from Clostridioides difficile is a rare complication of any antibiotic therapy
- Hearing changes during longer therapy require medical re evaluation
Interactions
- Other aminoglycosides and nephrotoxic agents: additive toxicity if systemic absorption occurs
- Diuretics (furosemide, ethacrynic acid): increased ototoxicity if systemic absorption occurs
- Muscle relaxants: enhanced neuromuscular blockade if systemic absorption occurs
- Vitamin K antagonists: possible INR rise via gut flora effects
- Digoxin: reduced absorption
Special considerations
Pregnancy and breastfeeding: oral use with minimal systemic absorption is considered acceptable. With intramuscular use (leishmaniasis) the same precautions as for other aminoglycosides apply.
Renal impairment: with intact gut mucosa no adjustment is required. With inflammatory bowel disease or mucositis accumulation is possible, so caution applies.
Liver disease: in hepatic encephalopathy paromomycin is specifically indicated, since action remains local in the gut.
Paediatrics: can be used in children with intestinal amoebiasis, with weight adapted dosing.
Treatment success: in amoebiasis stool samples should be examined for follow up to detect treatment success and reinfection. Hygiene measures (hand washing, safe drinking water, sanitation cleaning) are an important addition.
Patient communication: realistic information about treatment duration and the importance of completing therapy. In family infections or occupational contacts, joint treatment may be useful.
Related substances
- Lactulose, alternative in hepatic encephalopathy
- Lactolose, spelling variant
- Oxytetracycline, classical tetracycline
- Aztreonam, monobactam antibiotic
- Tigecycline, glycylcycline reserve antibiotic
Frequently asked questions
What is Humatin and who developed it?
Humatin is the brand name for paromomycin, an aminoglycoside antibiotic originally isolated from the soil bacterium Streptomyces krestomuceticus. It has been in clinical use since the 1960s.
Why is paromomycin so safe orally despite being an aminoglycoside?
Aminoglycosides are barely absorbed in the gut. Paromomycin is no exception: only about 1 to 5 % of the oral dose reaches systemic circulation. The typical aminoglycoside adverse effects such as nephrotoxicity and ototoxicity are therefore largely absent with oral use, provided the gut mucosa is intact.
When is paromomycin alone enough in amoebiasis?
Paromomycin only works against intestinal amoebae and cysts, not against tissue forms. In purely luminal infection without tissue invasion paromomycin alone is sufficient. In invasive amoebiasis (colitis, liver abscess) prior treatment with metronidazole is required, followed by paromomycin to eradicate luminal cysts.
Does paromomycin help in chronic diarrhoea?
Not in general. Paromomycin only works in specific pathogens such as Entamoeba histolytica or in hepatic encephalopathy. In chronic diarrhoea of unclear cause diagnostics should come first, since many causes (inflammatory bowel disease, functional symptoms, other infections) require different treatments.
Sources
- BfArM German Federal Institute for Drugs and Medical Devices
- EMA European Medicines Agency
- AWMF guidelines tropical and travel medicine
- Gelbe Liste paromomycin monograph
Legal notice and disclaimer
The information on this page is provided for general information only and does not constitute medical advice, diagnosis or treatment recommendation. It does not replace advice from a qualified physician or pharmacist. Medicines should only be used on prescription or after dispensing by a pharmacist. All information is based on the product information available at the time of writing and on recognised scientific sources; the manufacturer's current product information always prevails. Sanoliste assumes no liability for completeness, timeliness or accuracy of the information presented. In a medical emergency call the European emergency number 112.