Chemistry - A tetrahydropyrimidine anthelmintic, morantel tartrate occurs as a practically odorless, off-white to pale yellow, crystalline solid that is soluble in water. It has a melting range of 167-171°C. The tartrate salt is equivalent to 59.5% of base activity.
Storage/Stability/Compatibility - Morantel tartrate products should be stored at room temperature (15-30°C) unless otherwise instructed by the manufacturer.
Pharmacology - Like pyrantel, morantel acts as depolarizing neuromuscular blocking agent in susceptible parasites, thereby paralyzing the organism. The drug possesses nicotine-like properties and acts similarly to acetylcholine. Morantel also inhibits fumarate reductase in Haemonchus spp.. Morantel is slower than pyrantel in its onset of action, but is approximately 100 times as potent.
Uses/Indications - Morantel is indicated (labeled) for the removal of the following parasites in cattle: Mature forms of: Haemonchus spp., Ostertagia spp., Trichostrongylus spp., Nematodirus spp., Cooperia spp. and Oesophagostomum radiatum. It is also used in other ruminant species.
Pharmacokinetics - After oral administration, morantel is absorbed rapidly from the upper abomasum and small intestine. Peak levels occur about 4-6 hours after dosing. The drug is promptly metabolized in the liver. Within 96 hours of administration, 17% of the drug is excreted in the urine and the remainder in the feces.
Contraindications/Precautions - There are no absolute contraindications to using this drug. The sustained-release oral cartridges (Paratect®) are not to be used in cattle weighing less than 90 kg. Morantel is considered to be generally safe to use during pregnancy.
Adverse Effects/Warnings - At recommended doses, adverse effects are not commonly seen. For more information, see Overdosage section below.
Overdosage/Acute Toxicity - Morantel tartrate has a large safety margin. In cattle, dosages of up to 200 mg/kg (20 times recommended dose) resulted in no toxic reactions. The LD50 in mice is 5 g/kg. Symptoms of toxicity that might possibly be seen include increased respiratory rates, profuse sweating (in animals able to do so), ataxia or other cholinergic effects.
Chronic toxicity studies have been conducted in cattle and sheep. Doses of 4 times recommended were given to sheep with no detectable deleterious effects. Cattle receiving 2.5 times recommended dose for 2 weeks showed no toxic signs.
Drug Interactions - Paratect® cartridges should not be administered with mineral bullets as decreased anthelmintic efficacy can result. Because of similar mechanisms of action (and toxicity), morantel is recommended not to be used concurrently with pyrantel or levamisole. Observation for adverse effects should be intensified if used concomitantly with an organophosphate or diethylcarbamazine. Piperazine and morantel have antagonistic mechanisms of action; do not use together. Do not add to feeds containing bentonite.
For susceptible parasites:
a) 9.68 mg/kg PO. (Paul 1986), (Label Directions; Nematel®—Pfizer)
b) 8.8 mg/kg PO. (Roberson 1988b)
c) Paratect® Cartridges: One cartridge PO when animal placed onto spring pasture. All cattle grazing on same pasture must be treated. Effective for 90 days. (Label Directions; Paratect®—Pfizer)
a) Morantel tartrate 2-4 mg/kg orally as a single dose; Morantel citrate 2-3 mg/kg orally
as a single dose for helminthiasis (Chandrasekharan,2002),(Chandrasekharan et.al.,
1995), (Chandrasekharan, 1992).
b) 5 mg/kg orally for strongylosis (Chandrasekharan et.al., 1982).
Chandrasekharan,K. 2002. Specific diseases of Asian elephants.
Journal of Indian Veterinary Association Kerala 7:(3):31-34
a) Chandrasekharan,K., 1992. Prevalence of infectious diseases in elephants in Kerala and their treatment. In: Silas,E.G., Nair,M.K., and Nirmalan,G. (Editors), The Asian Elephant: Ecology, Biology, Diseases, Conservation and Management (Proceedings of the National Symposium on the Asian Elephant held at the Kerala Agricultural University, Trichur, India, January 1989). Kerala Agricultural University, Trichur,India pp. 148-155
b) Chandrasekharan,K., Cheeran,J.V., Nair,K.N.M., Ramanujam,K.N., and Radhakrishnan,K. 1982. Comparative efficacy of 6 anti-helminthics against strongylosis in elephants. Kerala Journal of Veterinary Science 13:15-20 Summary: Anthelmintic efficacy of six drugs was compared under field conditions against strongylosis in elephants. Mebendazole at 3 and 4 mg/kg, Levamisole 3 mg/kg and Morantel tartrate 5 mg/kg were proved to be 100% effective. Mebendazole at 2 mg/kg and 2.5 mg/kg, Thiabendazole at 32 mg/kg. Bephenium hydroxynaphthoate at 25 mg/kg and Disophenol at 3 mg/kg were found to be effective only in 79.1 to 92.2 %, 88.1 to 100%, 84.6 to 95.3 %, 85.9 to 100% and 68.3 to 84 % cases respectively.
Dosage Forms/Preparations/FDA Approval Status/Withdrawal Times -
Morantel Tartrate Oral Boluses 2.2 g (equiv. to 1.3 g base)
Nematel® Cattle Wormer Boluses (Pfizer); (OTC) Approved for use in beef or dairy cattle. Milk withdrawal = none; Slaughter withdrawal = 14 days
Morantel Tartrate Medicated Premix, 88 g morantel tartrate per lb.
Rumatel® Medicated Premix-88 (Pfizer); (OTC) Approved for use in beef or dairy cattle. Milk withdrawal = none; Slaughter withdrawal = 14 days
Morantel Tartrate Sustained-Release Oral Cartridges, 22.7 g per cartridge (13.5 g base)
Paratect® Cartridge (Pfizer); (OTC) Approved for use in beef or dairy cattle. Milk withdrawal = none; Slaughter withdrawal = 160 days
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