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Mefloquine Side Effects

Medically reviewed by Drugs.com. Last updated on March 16, 2020.

For the Consumer

Applies to mefloquine: oral tablet

Warning

Oral route (Tablet)

Mefloquine may cause neuropsychiatric adverse reactions that can persist after mefloquine has been discontinued. Mefloquine should not be prescribed for prophylaxis in patients with major psychiatric disorders. During prophylactic use, if psychiatric or neurologic symptoms occur, the drug should be discontinued and an alternative medication should be substituted

Side effects requiring immediate medical attention

Along with its needed effects, mefloquine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking mefloquine:

Rare

  • Aching joints and muscles
  • anxiety
  • blistering, loosening, peeling, or redness of the skin
  • chest pain or discomfort
  • chills
  • confusion
  • convulsions (seizures)
  • cough or hoarseness
  • dizziness
  • fainting
  • fever
  • hallucinations (seeing, hearing, or feeling things that are not there)
  • irregular, pounding, slow, or fast heartbeat or pulse
  • irritability
  • lightheadedness
  • lower back or side pain
  • mental depression
  • painful or difficult urination
  • pinpoint red spots on the skin
  • red or irritated eye
  • restlessness
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • stiff neck
  • swelling of the ankles, feet, or lower legs
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting

Incidence not known

  • Blurred or loss of vision
  • continuing ringing or buzzing or other unexplained noise in the ears
  • disturbed color perception
  • double vision
  • feeling of constant movement of self or surroundings
  • halos around lights
  • hearing loss
  • hearing problems
  • loss of balance
  • loss of bladder control
  • muscle spasm or jerking of all extremities
  • night blindness
  • overbright appearance of lights
  • sensation of spinning
  • severe or continuing headache
  • sudden loss of consciousness
  • trouble sleeping
  • troubled breathing
  • tunnel vision

Side effects not requiring immediate medical attention

Some side effects of mefloquine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

Rare

  • Loss of hair

Incidence not known

  • Acid or sour stomach
  • belching
  • flushing or redness of the skin
  • heartburn
  • indigestion
  • skin rash with a general disease
  • stomach discomfort, upset, or pain
  • swelling
  • unusually warm skin

For Healthcare Professionals

Applies to mefloquine: oral tablet

General

At the doses used for treatment of acute malaria infections, the side effects possibly associated with this drug could not be distinguished from the side effects usually associated with the disease. The most common side effects reported during treatment included dizziness, myalgia, nausea, fever, headache, vomiting, chills, diarrhea, skin rash, abdominal pain, fatigue, loss of appetite, and tinnitus.

The most common side effects reported during malaria prophylaxis included nausea, vomiting, and dizziness.

Due to the long half-life of this drug, side effects have occurred and persisted up to several weeks after drug discontinuation.[Ref]

Psychiatric

Very common (10% or more): Abnormal dreams/strange or vivid dreams (13.7%), insomnia (13.5%)

Common (1% to 10%): Depression, anxiety

Frequency not reported: Emotional problems, transient emotional disturbances, behavioral changes, mania, nightmares, delusions, tension, anger, organic psychosis, dysphoria

Postmarketing reports: Anxiety, depression, mood swings, panic attacks, confusion/confusional state, hallucinations, aggression, agitation, restlessness, psychotic/paranoid reactions, suicidal ideation, suicide, attempted suicide, self-endangering behavior, bipolar disorder, psychotic disorder (including delusional disorder, depersonalization, mania, schizophrenia/schizophreniform disorder), paranoia, disturbance in attention[Ref]

Gastrointestinal

Common (1% to 10%): Nausea, diarrhea, abdominal pain, mouth ulcers, vomiting

Postmarketing reports: Nausea, vomiting, abdominal pain, loose stools/diarrhea, dyspepsia, pancreatitis[Ref]

Nervous system

Encephalopathy of unknown etiology was reported during prophylactic use; however, the relationship to drug administration could not be established.[Ref]

Common (1% to 10%): Dizziness, vertigo, headache

Frequency not reported: Syncope, encephalopathy of unknown etiology, tinnitus, seizures, myoclonus

Postmarketing reports: Dizziness, vertigo, loss of balance/balance disorder, neuropsychiatric events (e.g., headache, somnolence), peripheral sensory and motor neuropathies (including paresthesia, tremor, ataxia), convulsions, agitation, restlessness, memory impairment, encephalopathy, vestibular disorders (including tinnitus, hearing impairment), cranial nerve paralysis, amnesia (some lasted more than 3 months), speech disorder, gait disturbance, partial deafness (sometimes prolonged), hyperacusis[Ref]

Dermatologic

Common (1% to 10%): Itching/pruritus

Frequency not reported: Skin rash, hair loss, telogen effluvium, cutaneous vasculitis

Postmarketing reports: Rash, exanthema, erythema, urticaria, pruritus, alopecia/hair loss, hyperhidrosis, erythema multiforme, Stevens-Johnson syndrome[Ref]

Ocular

Common (1% to 10%): Visual difficulties

Postmarketing reports: Visual impairment, blurred vision, cataracts, retinal disorders, optic neuropathy[Ref]

Cardiovascular

Frequency not reported: Extrasystoles, cardiopulmonary arrest, bradycardia, transitory and clinically silent ECG alterations (including sinus bradycardia, sinus arrhythmia, first degree atrioventricular block, prolongation of the QTc interval, abnormal T waves), atrial flutter

Postmarketing reports: Circulatory disturbances (hypotension, hypertension, flushing, syncope), chest pain, tachycardia, palpitation, bradycardia, irregular heart rate, extrasystoles, atrioventricular block, other transient cardiac conduction alterations[Ref]

Cardiopulmonary arrest was reported in 1 patient after a single prophylactic dose while concomitantly using propranolol.[Ref]

Hematologic

Frequency not reported: Decreased hematocrit, anemia, isolated thrombocytopenia, hemolytic anemia, thrombotic thrombocytopenic purpura

Postmarketing reports: Agranulocytosis, aplastic anemia, leukopenia, leukocytosis, thrombocytopenia[Ref]

A 56-year-old male experienced thrombotic thrombocytopenic purpura (TTP) coincident with use of this drug. A week before admission, the patient developed weakness, followed some days later by anorexia, myalgia, and lethargy, and, finally, by fever, confusion, and blurred vision. A central venous catheter was placed in the right jugular vein and 2 plasmapheresis sessions (12 units of fresh frozen plasma) were conducted in the first 24 hours. Neurological status improved after the first plasmapheresis; hematological abnormalities disappeared in the first few days of therapy. For this patient, the presence of severe neurological symptoms together with fever, thrombocytopenia, and microangiopathic anemia suggested a more complex hematological abnormality, such as TTP. The causal relation between drug and disease is supported by the temporal relation of drug intake with the onset of the clinical symptoms and laboratory abnormalities, as well as by their prompt improvement after the aphaeretic therapy and drug withdrawal.[Ref]

Other

Frequency not reported: Asthenia, fatigue, fever, chills, weakness

Postmarketing reports: Asthenia, edema, chest pain, malaise, fatigue, fever/pyrexia, chills[Ref]

Musculoskeletal

Frequency not reported: Myalgia, moderately severe arthralgias, moderately severe myalgias

Postmarketing reports: Muscle/muscular weakness, muscle spasms/cramps, myalgia, arthralgia[Ref]

Hypersensitivity

Frequency not reported: Hypersensitivity reactions (from mild cutaneous events to anaphylaxis)[Ref]

Respiratory

Frequency not reported: Eosinophilic pneumonia

Postmarketing reports: Dyspnea, pneumonitis of possible allergic etiology, pneumonia[Ref]

A 67-year-old female with a history of pityriasis versicolor experienced eosinophilic pneumonia coincident with infliximab therapy. She was admitted because she had experienced high-grade fever (39C), malaise, productive cough, and dyspnea on exertion during the previous week. She had traveled to South Africa for 8 weeks and had taken this drug (250 mg orally once a week) as malaria prophylaxis. The therapy was continued for 4 weeks after she returned home. A thorough workup led to the diagnosis of eosinophilic pneumonia due to this drug. Her condition improved after the drug was withdrawn.[Ref]

Hepatic

Frequency not reported: Transient elevation of transaminases

Postmarketing reports: Drug-related hepatic disorders (from asymptomatic transient transaminase elevations to hepatic failure), hepatic failure, hepatitis, jaundice, increased asymptomatic transient transaminases (ALT, AST, GGT)

Metabolic

Frequency not reported: Loss of appetite, anorexia

Postmarketing reports: Decreased appetite[Ref]

Renal

Postmarketing reports: Acute renal failure, nephritis, increased blood creatinine

References

1. "Mefloquine for malaria." Med Lett Drugs Ther 31 (1990): 13-4

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

4. Jimenez-Huete A, Gil-Nagel A, Franch O "Multifocal myoclonus associated with mefloquine chemoprophylaxis." Clin Neuropharmacol 25 (2002): 243

5. Harinasuta T, Bunnag D, Wernsdorfer WH "A phase II clinical trial of mefloquine in patients with chloroquine-resistant falciparum malaria in thailand." Bull World Health Organ 61 (1983): 299-305

6. Bjorkman A "Acute psychosis following mefloquine prophylaxis." Lancet 2 (1989): 865

7. Croft AMJ, World MJ "Neuropsychiatric reactions with mefloquine chemoprophylaxis." Lancet 347 (1996): 326

8. Hennequin C, Bouree P, Bazin N, Bisaro F, Feline A "Severe psychiatric side effects observed during prophylaxis and treatment with mefloquine." Arch Intern Med 154 (1994): 2360-2

9. Caillon E, Schmitt L, Moron P "Acute depressive symptoms after mefloquine treatment." Am J Psychiatry 149 (1992): 712

10. Weinke T, Trautmann M, Held T, et al "Neuropsychiatric side effects after the use of mefloquine." Am J Trop Med Hyg 45 (1991): 86-91

11. White NJ "Mefloquine." Br Med J 308 (1994): 286-7

12. Van Riemsdijk MM, Ditters JM, Sturkenboom MC, et al. "Neuropsychiatric events during prophylactic use of mefloquine before travelling." Eur J Clin Pharmacol 58 (2002): 441-5

13. Phillips M "Adverse events associated with mefloquine - women may be more susceptible to adverse events." BMJ 313 (1996): 1552-3

14. Brumbaugh M, Price P, Fagan N, Hsieh H "Psychotic mania associated with mefloquine in a bipolar patient." South Med J 101 (2008): 550-1

15. White NJ, Pukrittayakamee S "Clinical malaria in the tropics." Med J Aust 159 (1993): 197-203

16. Yelmo S, Morera-Fumero AL, Henry M, Renshaw A, Gracia-Marco R "Mania associated with mefloquine prophylaxis." J Clin Psychopharmacol 30 (2010): 339-41

17. Winstanley P "Malaria: treatment." J R Coll Physicians Lond 32 (1998): 203-7

18. Bem JL, Kerr L, Stuerchler D "Mefloquine prophylaxis: an overview of spontaneous reports of severe psychiatric reactions and convulsions." J Trop Med Hyg 95 (1992): 167-79

19. "Product Information. Lariam (mefloquine)." Roche Laboratories, Nutley, NJ.

20. Stuiver PC, Ligthelm RJ, Goud TJ "Acute psychosis after mefloquine." Lancet 2 (1989): 282

21. Speich r, Haller A "Central anticholinergic syndrome with the antimalarial drug mefloquine." N Engl J Med 331 (1994): 57-8

22. Piening RB, Young SA "Mefloquine-induced psychosis." Ann Emerg Med 27 (1996): 792-3

23. Meszaros K "Acute psychosis caused by mefloquine prophylaxis?" Can J Psychiatry 41 (1996): 196

24. Overbosch D, Schilthuis H, Bienzle U, et al. "Atovaquone-Proguanil versus Mefloquine for Malaria Prophylaxis in Nonimmune Travelers: Results from a Randomized, Double-Blind Study." Clin Infect Dis 33 (2001): 1015-21

25. Eaton L "Mefloquine has more adverse effects than other drugs for malaria prophylaxis." BMJ 339 (2009): b4167

26. Freedman DO "Clinical practice. Malaria prevention in short-term travelers." N Engl J Med 359 (2008): 603-12

27. Rouveix B, Bricaire F, Michon C, et al "Mefloquine and an acute brain syndrome." Ann Intern Med 110 (1989): 577-8

28. Bakshi R, Hermeling-Fritz I, Gathmann I, Alteri E "An integrated assessment of the clinical safety of artemether-lumefantrine: a new oral fixed-dose combination antimalarial drug." Trans R Soc Trop Med Hyg 94 (2000): 419-24

29. Ekue JM, Ulrich A-M, Rwabwogo-Atenyi J, Sheth UK "A double-blind comparative clinical trial of mefloquine and chloroquine in symptomatic falciparum malaria." Bull World Health Organ 61 (1983): 713-8

30. Lobel HO, Bernard KW, Williams SL, et al "Effectiveness and tolerance of long-term malaria prophylaxis with mefloquine: need for a better dosing regimen." JAMA 265 (1991): 361-4

31. Held T, Trautmann M, Weinke T, Mravak S "A prospective clinical trial of the treatment of falciparum malaria with mefloquine, with special reference to neuro-psychiatric side effects." Trans R Soc Trop Med Hyg 85 (1991): 444-5

32. ter Kuile FO, Nosten F, Thieren M, et al "High-dose mefloquine in the treatment of multidrug-resistant falciparum malaria." J Infect Dis 166 (1992): 1393-400

33. Terkuile FO, Nosten F, Luxemburger C, Kyle D, Tejaisavatharm P, Phaipun L, Price R, Chongsuphajaisiddhi T, White NJ "Mefloquine treatment of acute falciparum malaria: a prospective study of non-serious adverse effects in 3673 patients." Bull World Health Organ 73 (1995): 631-42

34. De Souza J-M "A phase I clinical trial of mefloquine in brazilian male subjects." Bull World Health Organ 61 (1983): 809-14

35. Olson PE, Kennedy CA, Morte PD "Paresthesias and mefloquine prophylaxis." Ann Intern Med 117 (1992): 1058-9

36. Gullahorn GM, Bohman HR, Wallace MR "Anaesthesia emergence delirium after mefloquine prophylaxis." Lancet 341 (1993): 632

37. Jallon P "Use of mefloquine in epileptic patients." J Neurol Neurosurg Psychiatry 51 (1988): 732

38. Choo V "Uncertainty about mefloquine will take time to resolve." Lancet 347 (1996): 891

39. Ruff TA, Sherwen SJ, Donnan GA "Seizure associated with mefloquine for malaria prophylaxis." Med J Aust 161 (1994): 453

40. Singh K, Shanks GD, Wilde H "Seizures after mefloquine." Ann Intern Med 114 (1991): 994

41. Martin GJ, Malone JL, Ross EV "Exfoliative dermatitis during malarial prophylaxis with mefloquine." Clin Infect Dis 16 (1993): 341-2

42. Scerri L, Pace JL "Mefloquine-associated cutaneous vasculitis." Int J Dermatol 32 (1993): 517-8

43. Australian Government. Department of Health. Therapeutic Goods Administration "Mefloquine hydrochloride (Larium): Safety advisory - potential for visual disturbances. Available from: URL: http://www.tga.gov.au/safety/alerts-medicine-mefloquine-hydrochloride-131011.htm." ([2013 Oct 11]):

44. Terkuile FO, Luxemburger C, Nosten F, Thwai KL, Chongsuphajaisiddhi T, White NJ "Predictors of mefloquine treatment failure: a prospective study of 1590 patients with uncomplicated falciparum malaria." Trans R Soc Trop Med Hyg 89 (1995): 660-4

45. Fonteyne W, Bauwens A, Jordaens L "Atrial flutter with 1:1 conduction after administration of the antimalarial drug mefloquine." Clin Cardiol 19 (1996): 967-8

46. Nosten F, ter Kuile FO, Luxemburger C, et al "Cardiac effects of antimalarial treatment with halofantrine." Lancet 341 (1993): 1054-6

47. Lench P "Malaria prophylaxis - psychological problems after mefloquine and chloroquine." BMJ 311 (1995): 192

48. Kozarsky P, Eaton M "Use of mefloquine for malarial chemoprophylaxis in its first year of availability in the United States." Clin Infect Dis 16 (1993): 185-6

49. Stracher AR, Stoeckle MY, Giordano HF "Aplastic anemia during malarial prophylaxis with mefloquine." Clin Infect Dis 18 (1994): 263-4

50. Fiaccadori E, Maggiore U, Rotelli C, et al. "Thrombotic-thrombocytopenic purpura following malaria prophylaxis with mefloquine." J Antimicrob Chemother 57 (2005): 160-1

51. Van Den Eden E, Van Gompel A, Colebunders R, Van Den Ende J "Mefloquine-induced Stevens-Johnson syndrome." Lancet 337 (1991): 683

52. White AC "Cutaneous vasculitis associated with mefloquine." Ann Intern Med 123 (1995): 894

53. Shlim DR "Severe facial rash associated with mefloquine." JAMA 266 (1991): 2560

54. Katsenos S, Psathakis K, Nikolopoulou MI, Constantopoulos SH "Mefloquine-induced eosinophilic pneumonia." Pharmacotherapy 27 (2007): 1767-71

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.