Reals Pharmaceuticals Limited
Plot 1 Junaid Dosunmu Street,Central Business District, Alausa, P.0. Box 3560 Ikeja, Lagos, Nigeria.
Tel: + 234-1-774-1205
Fax: +234-1-263-0919

Brand Name



Rajrab Ltd, 72-80 Coca Cola Rd, Industrial Estate, Ilorin, Kwara State, Nigeria

Therapeutic Class


Dosage Form, Composition & NAFDAC Registration Number (NRN)

Syrup (NRN: 04-4163): Levamisole HCl Ph. Eur. 47.2 mg (equiv. to 40 mg Levamisole) per 5 mL.

Pack Size

retrax syrup



Levamisole is a fast acting drug which acts on nematode nerve ganglia paralysing the worm’s musculature within minutes of contact unable to maintain their position, the worms are then ejected by normal peristalic movement usually within 24 hours of levamisole administration.

Although it is certain that levamisole primarily influences the neuromuscular system of nematodes, it is possible that in some helminths the inhibition of the fumarate reductase system contributes to the anthelmintic efficacy of levamisole.


Levamisole is rapidly and almost completely absorbed from the gastrointestinal tract. A dose of 2.5 mg/kg gives peak plasma levels of 0.5-0.7 microgram/mL within two hours.

The drug is rapidly and extensively metabolised in the liver. One metabolite (hydroxylevamisole) has been identified in the urine of man, but several other unidentified metabolites are formed. The elimination of the drug is rapid (a plasma half - life of about four hours) Approximately 70% of the dose eliminated in urine within 72 hours and only 4% in faeces. Less 6% of the dose is excreted unchanged.


Levamisole indicated for the treatment of infections by the following gastrointestinal worms species: Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Enterobius vermicularis, Trichuris trichiura, Strongyloides strercoralis, Trichostronglylus colubriformis.


Previous allergy to Retrax or any of its components.


In cases on concurrent microfilaraemia transient fever may occur.


Pregnancy: Although studies in animals have shown that. Retrax produces no teratogenic effects, current medical practice requires that the benefits of any drug used during pregnancy should be weighed against the possible dangers.

Lactation: No special precautions.

Effects on ability to drive or operate machinery: There is no evidence to suggest that levamisole, used for anthlemintic purposes, will produce sedation. Mild and transient giddiness (dizziness) is an infrequent side effects of treatment. No precautions are suggested concerning the ability to operate machinery.


None known

Adverse Effects

These are infrequent. They are usually mild and transient and include nausea, vomiting, abdominal pain, giddiness and headache.

An encephalopathy-like syndrome has been reported to have occurred in a few patients two three weeks after treatment.

Allergic reactions have been reported following repeated exposure.

Dosage & Administration

The following doses of Retrax are given as a single administration, preferably after a light meal.

 Patient’s age in years  Dose
 1-4     5 mL
 5-15   10 mL
 16 and over   15 mL

 In cases of severe hookworm infection it is suggested that a second standard dose be given one or seven days after the first, whichever timing is feasible.


Counter possible anticholinesterase activity with e.g. Atropine.

Control blood pressure and respiration.

Do not give sedatives.

Storage/Handling Recommendations

Review Date

2016-09-01 04:51:24