Halofantrine Hcl - @ - Antimalarial - Investigational Drugs
Drug Name:Halofantrine Hcl - @ - Antimalarial - Investigational Drugs
List Of Brands:
Indication Type Description:
Indication
Adverse Reaction
Patient Information
Pharmacology/ Pharmacokinetics
Indication:
Malaria
Summmary-
Halofrantine appears to be safe and selective alternative to current therapy for
Plasmodium falciparium malaria. Additional studies are needed to delineate the
role of the true drugresistence versus bioavailability factors as causes for treatment
failures.
Its role in the treatment of P ovale , P vivax and P malariae has not been determined .
halofantrine was approved by the FDA on July 1992, however it is not yet commercially
available. A release date is unknown.
Adverse Reaction:
Side effects
Abdominal pain, vomiting and diarrhea have occurred in 15% to 25% of treated patients
Whether these represent drug- or disease- related events is difficult to distinguish.
Puritus occurs in 2.3% of patients and represents an advantage for African patients.
The puritus has been characterized as a generalised buring sensation, most pronounced
on the soles of the feet, scalp and periphreal areas.
Onset is usually within the first 14 hours with resolution after 20 hours. Headache and
rash have occurred. Anectodal reports of neuromuscular spasm, mouth ulcers,
seizures, venticular ectopy (PVCs) and intervascular hemolysis have been attributed
to halofantrine cause and effect have not been established.
Patient Information:
Ref - USP PDI Vol II 17th Edition (1997)
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to
halofanthene. Also tell your healthcare care professional if you are allergic to
any other substances such as foods. preservatives or dyes.
2.Pregnancy-
Halofanthine has not been studied in pregnant women.Before taking
this medicine consult your doctor.
3. Breast-feeding-
Halofanthine may pass into breast milk and cause unwanted side effects on nursing
babies. Be sure you discuss the risk and benefits with your doctor.
4.Children-
This medicine is not expected to cause different side effects or problems in children
than it does in adults.
5.Older adults-
There is no specific information comparing use of halofanthine in the elderly with use
in other age groups
6. Other medicines-
Although certain medicines should not be used together at all, in other cases two
different medicines may be used together even if an interaction might occur.
In such cases your doctor may want to change the dose, or other precautions
may be necessary.
Tell your doctor if you are using any of the following-
Mefloquine - recent use of mefloquine increases the chance of side effects.
affecting the heart including heart beat.
Pharmacology/ Pharmacokinetics:
Pharmacology-
Halofrantine , an antimalarial agent developed by the U.S. Army Antimalarial Program,
is an active multi-drug resistent Plasmodium falciparum malaria.
it is phenantrenemethanol, structurally related to mefloquine (Larium) .
Halofrantine and its active metabolite , N-desbutylhalofantrine (DHF) are blood
schizotocides active against the erythrocyte stages of /plasmodium sp.
The mechanism of active has not been fully elucidated, but may be similar to
other blood parasite interface. In vitro and clinical trials data suggest that cross-
resistence ocurs with mefloquine resistent strains.
Pharmacokinetics-
Following oral admin. absorption is erratic and variable, with a high degree of
intra-and subject variability . Influential factors seem to include dietary fat content
and the presence or absence of active disease.
Maximum plasma concentration ( Cmax) and and area under curve AUC of both the
parent and active metabolite are significantly increased (up to 6 fold) following
administration with a high fat meal. AUC and Cmax are proptionately related to dose
in the range of 500mg to 1000mg. In patients with active disease the half-life for
both the compounds is approximately 4 days.
The drug is widely distributed in most tissues and is excreted mainly in the feces
as unchanged drug
Clinical trials-
Non-comparative trials, using oral doses of 500mg every 6 hours for 3 doses in adults
and children < 40kg (8mg/kg) in smaller children ) have shown the drug to be effective in
the treatment of P falciparum infections.
A second course of therapy administered 7 days after initial treament is recommended for
patients as non-immune travelers or young children with no previous ( or minimal)
exposure to malaria.
Cure rates of 83% to 100% have been reported in areas of very high rates of P falciparum
malaria resistent to chloroquine and sulphonamide/pyrimethamine(eg.Fansidan)
Following treatment , many symptoms improve within the first day.
Fever usually decreased within 18 to 100 hours while parasites clear within 34 to 78 hours
in more cases. Resolution of splenomegaly and hepatomegaly occurs in approximately
75% of the treated patients.
A relapse rate of 5.8% has been reported , but it was noted that some of these cases
may have represented reinfection. Experience in treatment of P ovales and P malariae
is too limited to be conclusive. Present trials do not support halofantrines use for
prophylaxis
