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mefloquine hydrochloride

Apo-Mefloquine (CA), Lariam

Pharmacologic class: 4-quinolinemethanol derivative, quinine analog

Therapeutic class: Antimalarial

Pregnancy risk category C


Unknown. Thought to increase intravesicular pH in parasite acid vesicles and form complexes with hemin, inhibiting parasite development.


Tablets: 250 mg

Indications and dosages

Acute malarial infection

Adults: 1,250 mg P.O. as a single dose

Children: 20 to 25 mg/kg P.O. in two divided doses given 6 to 8 hours apart

Malaria prophylaxis

Adults and children weighing more than 45 kg (99 lb): 250 mg P.O. once weekly on same day each week, starting 1 week before entering endemic area and continuing for 4 weeks after leaving area

Children weighing 30 to 45 kg (66 to 99 lb): 187.5 mg P.O. q week

Children weighing 20 to 30 kg (44 to 66 lb): 125 mg P.O. q week

Children weighing 10 to 20 kg (22 to 44 lb): 62.5 mg P.O. q week

Children weighing 5 to 10 kg (11 to 22 lb): 31.25 mg P.O. q week


• Hypersensitivity to drug, related agents (quinine, quinidine), or excipients

• Prophylactic use in patients with active depression, recent history of depression, generalized anxiety disorder, psychosis, schizophrenia, other psychiatric disorders, or history of seizures


Use cautiously in:

• cardiac disorders, seizure disorders

• pregnant or breastfeeding patients

• children.


• Don't give on empty stomach. Administer with at least 240 ml of water.

• Know that after completing mefloquine therapy for acute malarial infection, patient should receive primaquine (or other 8-aminoquinolone) to prevent relapse.

Adverse reactions

CNS: dizziness, syncope, headache, psychotic changes, depression, hallucinations, confusion, anxiety, fatigue, vertigo, seizures

EENT: blurred vision, tinnitus

GI: nausea, vomiting, diarrhea, loose stools, abdominal discomfort, anorexia

Hematologic: leukopenia, thrombocytopenia

Musculoskeletal: myalgia

Skin: rash

Other: fever, chills


Drug-drug. Beta-adrenergic blockers, quinidine, quinine: ECG abnormalities, cardiac arrest

Chloroquine, quinine: increased risk of seizures

Valproic acid: decreased valproic acid blood level, loss of seizure control

Drug-diagnostic tests. Hematocrit, platelets, white blood cells: decreased values

Transaminases: transient increases

Patient monitoring

Monitor patient with acute Plasmodium vivax malaria who is at high risk for relapse. Because drug doesn't eliminate exoerythrocytic (hepaticphase) parasites, patient should receive primaquine after mefloquine therapy.

Watch for psychiatric symptoms, such as acute anxiety, depression, restlessness, or confusion. These may precede more serious psychiatric events.

• Evaluate hepatic function during prolonged prophylactic therapy.

In patients receiving related drugs (such as quinine, quinidine, or chloroquine) concurrently, be alert for ECG abnormalities and seizures. Separate administration times by at least 12 hours.

Closely monitor patients with serious or life-threatening Plasmodium falciparum infection. Be aware that they should receive I.V. antimalarial drugs and that mefloquine may be used to complete course of therapy.

Patient teaching

• Tell patient to take with full glass of water and not on empty stomach.

• In prophylactic use, instruct patient to take first dose 1 week before departure and to continue therapy as prescribed upon return. Tell him to take drug on same day each week.

• Advise patient to report fever after returning from malarious area.

• Inform patient that malaria prophylaxis should include protective clothing, insect repellent, and bed netting.

Tell patient to immediately report psychiatric symptoms (such as acute anxiety, depression, restlessness, or confusion) and to stop taking drug.

• Caution patient to avoid driving and other hazardous activities because drug may cause dizziness.

• Instruct patient to have periodic ophthalmic exams, because drug may cause eye damage.

• Tell female patient to inform prescriber if she is pregnant.

• Advise female patient not to breastfeed while taking drug.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


A trademark for the drug mefloquine hydrochloride.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


The prophylactic agent of choice for preventing malaria in those travelling to areas with drug-resistant Plasmodium falciparum.
Adverse effects
GI tract disturbances, dizziness; at high doses, convulsions, hallucinations.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Mefloquine, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A brand name for MEFLOQUINE.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
"This was because she was unhappy with the armed soldiers [the Irish] being in the same camp as her German troops while taking Lariam, as she was afraid they would become violent."
It said it was "deeply disturbing" that some personnel apparently preferred to throw away the Lariam they had been prescribed and run the risk of contracting malaria, rather than take the drug.
Lariam is known to cause severe psychiatric problems in a number of people who take it; the question of whether it causes suicide remains officially open.
There has been controversy over Lariam, an anti-malarial drug which can cause psychosis.
for an example of how Roche used a crisis team to respond to a case study involving its anti-malarial drug Lariam.
Lariam, the most widely prescribed antimalarial medicine, has disabling side effects for only a very small number of people.
A course of Lariam in the weeks before travelling will help to safeguard against the disease, but is not 100 per cent effective.
Matthew Parris, the broadcaster and writer, has said that he would have preferred malaria to the side-effects of Lariam, the drug he was told to take to protect himself against it.
We have two drugs here that can treat malaria: Fansidar and Lariam. Neither is to be taken willy-nilly.
That's not to mention the controversy over the Army's use of anti-malaria drug Lariam, which can cause serious psychotic side effects.
For this reason, I sometimes transition my patients to Lariam (mefloquine), which gets into the brain better.