Posology : מינונים

Dosage and Administration

1
CDS 5.0
Mefloquine has a bitter and slightly burning taste. Lariam tablets should be swallowed whole, with at least one glass of liquid. The tablets may be crushed and suspended in a small amount of water, milk or other beverage for administration to small children and other persons unable to swallow them whole.

Prophylaxis standard dosage
The recommended prophylactic dose of Lariam is approximately 5 mg/kg bodyweight once weekly: 
Bodyweight (kg)              Dose

5 – 10 kg*
10 – 20 kg                 ¼ tablet
20 – 30 kg                 ½ tablet
30 – 45 kg                 ¾ tablet
> 45 kg                 1 tablet
*Exact doses for children weighing less than 10 kg may best be prepared and dispensed by pharmacists.
Weekly doses should be taken regularly, always on the same day of each week, preferably after the main meal. The first dose should be taken at least one week before arrival in an endemic area.

Experience with Lariam in infants less than 3 months old or weighing less than 5 kg is limited. The dosage for children has been extrapolated from the recommended adult dose (see Pharmacokinetic Properties).

Therapy standard dosage
The recommended total therapeutic dose of mefloquine is 20 – 25 mg/kg bodyweight: 
Bodyweight (kg)          Total dose            Split dose (*)
5 – 10 kg               ½ – 1 tablet          –
10 – 20 kg               1 – 2 tablets         –
20 – 30 kg               2 – 3 tablets         2+1
30 – 45 kg               3 – 4 tablets         2+2
45 – 60 kg                   5 tablets         3+2
> 60 kg                   6 tablets         3+2+1

* Splitting the total therapeutic dosage into 2–3 doses taken 6–8 hours apart may reduce the occurrence or severity of adverse effects.

Experience with Lariam in infants less than 3 months old or weighing less than 5 kg is limited.

There is no specific experience with total dosages of more than 6 tablets in very heavy patients.
Special dosage instructions
Prophylaxis
For last-minute travellers to high-risk areas, if the start of prophylaxis one week before arrival in the endemic area is not possible, a ”loading dose” administration, consisting of the weekly dosage administered daily for three consecutive days followed, thereafter, by standard weekly dosing, is recommended:

 day 1                    1st dose day 2                    2nd dose day 3                    3rd dose thereafter               regular weekly doses
The use of a loading dose may be associated with an increased incidence of adverse events.

In certain cases, e.g. when a traveller is taking other medication, it may be desirable to start prophylaxis 2 to 3 weeks prior to departure, in order to ensure that the combination of medicines is well tolerated
(see Interactions with Other Medicinal Products and Other Forms of Interaction).

To reduce the risk of malaria after leaving an endemic area, prophylaxis must be continued for 4 additional weeks to ensure suppressive blood levels of the medicine when merozoites emerge from the liver.

When prophylaxis with Lariam fails, physicians should carefully evaluate which antimalarial to use for therapy. Regarding the use of halofantrine, see Warnings and Precautions; and Interactions with Other Medicinal Products and Other Forms of Interactions.

Therapy
For partially immune individuals, i.e. for inhabitants of malarious endemic areas, a reduced dose may be adequate.

A second full dose should be given to patients who vomit less than 30 minutes after receiving Lariam. If vomiting occurs 30 to 60 minutes after a dose, an additional half-dose should be given.

After treatment of P. vivax malaria, relapse prophylaxis with an 8-aminoquinoline derivative (e.g.
primaquine) should be considered in order to eliminate liver forms.

If a full treatment course with Lariam does not lead to improvement within 48 to 72 hours, Lariam should not be used for retreatment. An alternative therapy should be used. When breakthrough malaria occurs during Lariam prophylaxis, physicians should carefully evaluate which antimalarial to use for therapy.
Regarding the use of halofantrine, see Warnings and Precautions; and Interactions with Other Medicinal Products and Other Forms of Interactions.

Lariam can be given for severe acute malaria after an initial course of intravenous quinine lasting at least 2 – 3 days. Interactions leading to adverse events can largely be prevented by allowing an interval of at least 12 hours after the last dose of quinine.

In areas with multiresistant malaria, initial treatment with artemisinin or a derivative, if available, followed by Lariam is also an option.

Stand-by treatment
Lariam may be prescribed for use as stand-by medication when prompt medical attention is unavailable within 24 hours of onset of symptoms. Self-treatment should be started with a dose of about 15 mg/kg; for patients weighing 45 kg or more the initial dose would thus be 3 Lariam tablets. If it will not be possible to obtain professional medical care within 24 hours, and no severe side-effects occur, a second fraction of the total therapeutic dosage should be taken 6 – 8 hours later (2 tablets in patients weighing 45 kg or more). Patients weighing more than 60 kg should take an additional tablet 6 – 8 hours after the second dose. (See dosage recommendations for therapy above.)

Patients should be advised to consult a physician as soon as possible after self-treatment, even if they feel they have fully recovered to confirm or reject the presumptive diagnosis.