Oxamniquine (Systemic)
 |
VA CLASSIFICATION
Primary: AP200
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).
*Not commercially available in the U.S.
†Not commercially available in Canada.
Category:
Anthelmintic (systemic)—
Indications
Note: Because systemic oxamniquine is not commercially available in the U.S. or Canada, the bracketed information and the use of the superscript 1 in this monograph reflect the lack of labeled (approved) indications for this medication in these countries. {12}
Accepted
[Schistosomiasis (treatment)]1—Oxamniquine is indicated as alternative therapy in the treatment of all stages, including the acute phase and chronic phase with hepatosplenic involvement, of schistosomiasis (bilharziasis) caused by Schistosoma mansoni . {01} Praziquantel is considered to be the drug of choice. {11} Oxamniquine is also indicated in the treatment of decompensated hepatosplenic disease and in severe diffuse colonic polyposis caused by S. mansoni . {06}
Unaccepted
Oxamniquine is not effective against other Schistosoma species.
1 Not included in Canadian product labeling.
Pharmacology/Pharmacokinetics
Physicochemical characteristics:
Molecular weight—
279.34 {04}
Mechanism of action/Effect:
Schistosomicidal against both immature and mature worms. Oxamniquine causes the worms to shift from the mesenteric veins to the liver where they are destroyed. {07} Male schistosomes are more susceptible than females; however, after successful treatment with oxamniquine, the residual female schistosomes cease to lay eggs. {01}
Absorption:
Well absorbed orally; {01} {06} however, food significantly delays absorption.
Biotransformation:
Probably hepatic; extensively metabolized to inactive acidic metabolites; primary metabolite is the 6-carboxy metabolite.
Half-life:
1 to 2.5 hours. {01}
Time to peak serum concentration
1 to 1.5 hours. {01}
Elimination:
Renal, 0.4 to 1.9% excreted unchanged in urine {06} {07}; approximately 40 to 70% excreted as 6-carboxy metabolite {07}; primary metabolite largely excreted within first 12 hours.
Fecal, minimal (in animals).
Precautions to Consider
Pregnancy/Reproduction
Pregnancy—
Oxamniquine crosses the placenta. Adequate and well-controlled studies in humans have not been done. However, there have been no reports of abnormalities in the pregnancies, births, or children of women who received oxamniquine during pregnancy. {01} {10}
Studies in animals have shown that oxamniquine is embryocidal in rabbits and mice when given in doses 10 times the usual human dose.
FDA Pregnancy Category C.
Breast-feeding
It is not known whether oxamniquine is distributed into breast milk. However, problems in humans have not been documented. {01}
Pediatrics
Oxamniquine has been used in children, and no pediatrics-specific problems have been documented to date. Because strains of S. mansoni in South America and the Caribbean are more difficult to eradicate in children than adults, the total dosage for children in these areas is higher than for adults.
Geriatrics
No information is available on the relationship of age to the effects of oxamniquine in geriatric patients.
Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).
Risk-benefit should be considered when the following medical problems exist
» Epilepsy or other seizure disorders, history of{01}{05} (seizures may be more likely to occur in patients receiving oxamniquine who have a history of seizure disorders)
Hypersensitivity to oxamniquine
Side/Adverse Effects
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:
Those indicating need for medical attention
Incidence rare {05} {08} {10}
Fever —seen primarily in Egyptian patients
neuropsychiatric reactions (auditory or visual hallucinations)
seizures —more frequent in patients with history of seizure disorders
skin rash or hives
Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
—about 33%{05}
Dizziness
drowsiness
headache
Incidence less frequent
Gastrointestinal disturbances (abdominal or stomach pain; diarrhea; loss of appetite; nausea or vomiting)
Those not indicating need for medical attention {07}
Reddish orange discoloration of urine
Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Oxamniquine (Systemic) .
In providing consultation, consider emphasizing the following selected information (» = major clinical significance):
Before using this medication
» Conditions affecting use, especially:
Hypersensitivity to oxamniquine
Pregnancy—Oxamniquine crosses the placenta
Other medical problems, especially epilepsy or a history of seizure disorders
Proper use of this medication
No special preparations (e.g., dietary restrictions or fasting, concurrent medications, purging, or cleansing enemas) required before, during, or immediately after therapy
» Taking after meals to minimize possibility of side effects (gastric irritation, drowsiness, or dizziness)
» Compliance with therapy
» Proper dosing
Missed dose: Taking as soon as possible; not taking if almost time for next dose; not doubling doses
» Proper storage
Precautions while using this medication
Regular visits to physician to check progress
Checking with physician if no improvement after completing course of therapy
» Caution if dizziness or drowsiness occurs
Side/adverse effects
Reddish orange discoloration of urine may be alarming to patient although medically insignificant
Signs of potential side effects, especially fever, hallucinations, seizures, and skin rash or hives
General Dosing Information
No special preparations (e.g., dietary restrictions or fasting, concurrent medications, purging, or cleansing enemas) are required before, during, or immediately after treatment with oxamniquine.
Oxamniquine should be taken after meals to minimize possibility of side effects. {01}
Oxamniquine has also been administered intramuscularly in doses of 7.5 mg per kg of body weight (mg/kg) as a single dose. However, because of severe local pain at the injection site, oxamniquine is recommended only for oral use. {10}
Oral Dosage Forms
Note: Because systemic oxamniquine is not commercially available in the U.S. or Canada, the bracketed uses and the use of the superscript 1 in this monograph reflect the lack of labeled (approved) indications for this medication in these countries.
OXAMNIQUINE CAPSULES USP
Usual adult and adolescent dose
[Schistosomiasis]1{01} {09}
East African strains of S. mansoni:
Oral, 15 mg per kg of body weight two times a day for one day.
North and South African strains of S. mansoni:
Oral, 15 mg per kg of body weight two times a day for two days.
West African and Western Hemisphere strains of S. mansoni:
Oral, 15 mg per kg of body weight as a single dose.
Usual pediatric dose
[Schistosomiasis]1{01} {09}
East African strains of S. mansoni:
Oral, 15 mg per kg of body weight two times a day for one day.
North and South African strains of S. mansoni:
Oral, 15 mg per kg of body weight two times a day for two or three days.
West African and Western Hemisphere strains of S. mansoni:
Children weighing up to 30 kg: Oral, 10 mg per kg of body weight per dose for two doses given two to eight hours apart.
Children weighing 30 kg and over: See Usual adult and adolescent dose.
Strength(s) usually available
U.S.—
Not commercially available.
Canada—
Not commercially available. {03}
Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer. Store in a tight container.
Auxiliary labeling:
• May cause dizziness or drowsiness.
• Take after meals.
• Continue medication for full time of treatment.
Revised: 06/11/1999
References
- PDR 1989, Vansil (Pfizer), p 1625.
- Open.
- Personal communication, Pfizer (Canada), 7/21/89.
- USAN 1989, p 405.
- Krajden S, Keystone J, Glenn C. Safety and toxicity of oxamniquine in the treatment of Schistosoma mansoni infections, with particular reference to electroencephalographic abnormalities. Am J Trop Med Hyg 1983; 32(6): 1344-6.
- Kilpatrick ME, et al. Treatment of schistosomiasis mansoni with oxamniquine–five years' experience. Am J Trop Med Hyg 1981; 30(6): 1219-22.
- Goodman and Gilman (eds). The pharmacologic basis of therapeutics, 7th ed. 1985. New York: Macmillan, pp 1016-7.
- Stokvis H, et al. Seizures associated with oxamniquine therapy. Am J Trop Hyg 1986; 35(2): 330-1.
- Mandell, Douglas, Bennett (eds). Principles and practice of infectious diseases, 3rd ed. 1990. New York: Churchill Livingstone, pp 404-5.
- Foster R. A review of clinical experience with oxamniquine. Trans R Soc Trop Med Hyg 1987; 81(1): 55-9.
- Drugs for parasitic infections. Med Lett Drugs Ther 3/23/90; 32(814): 23-32.
- Reynolds EF, editor. Martindale: the extra pharmacopeia. 31st ed. London: Royal Pharmaceutical Society; 1996. p. 121-2.
 |
Link to Page |  |
Print Page |  |
Email Page |
