Lariam (mefloquine hydrochloride) is a prescription antimalarial medication developed for the prevention and treatment of malaria caused by Plasmodium falciparum and Plasmodium vivax. As a long-acting chemoprophylactic agent, it is particularly suited for travelers visiting regions with high malaria transmission and chloroquine-resistant strains. Its once-weekly dosing regimen offers significant convenience and adherence benefits compared to daily alternatives. Healthcare providers consider Lariam an important tool in malaria prevention strategies for appropriate patient populations.

Features

• Contains 250mg mefloquine hydrochloride per tablet
• Once-weekly oral dosing schedule for prophylaxis
• Effective against chloroquine-resistant Plasmodium falciparum
• Long half-life (approximately 21 days) providing continuous protection
• FDA-approved for both prevention and treatment of malaria
• Available in blister packs with clear weekly dosing indications

Benefits

• Provides reliable protection against malaria in endemic regions
• Reduces dosing frequency to once weekly, improving travel convenience
• Offers protection against drug-resistant malaria strains
• Maintains effectiveness throughout extended stays in malaria-risk areas
• Can be used for both prophylaxis and treatment protocols
• Eliminates need for daily medication reminders during travel

Common use

Lariam is primarily prescribed for malaria prophylaxis in travelers aged 6 months and older visiting areas with chloroquine-resistant malaria. It is particularly indicated for individuals traveling to sub-Saharan Africa, Southeast Asia, and South America where malaria transmission rates are high. The medication is also used for treatment of acute malaria infections when appropriate. Military personnel, long-term travelers, and expatriates frequently use Lariam due to its convenient dosing schedule and effectiveness against resistant strains.

Dosage and direction

For prophylaxis in adults: 250 mg (one tablet) orally once weekly. Begin administration 1-2 weeks before travel to endemic areas, continue weekly during exposure, and for 4 weeks after leaving malaria-endemic areas.

For prophylaxis in children:

• 5-19 kg: 5 mg/kg once weekly
• 20-30 kg: ¼ tablet (62.5 mg) once weekly
• 31-45 kg: ½ tablet (125 mg) once weekly
• Over 45 kg: adult dosage

For treatment of malaria: 1250 mg (5 tablets) as a single dose under medical supervision. Take with at least 8 ounces of water, preferably following a meal to minimize gastrointestinal discomfort.

Precautions

Prior to prescribing Lariam, conduct thorough medical and psychiatric history assessment. Monitor patients for signs of psychiatric disturbances during prophylaxis. Use with caution in patients with cardiac conduction abnormalities, epilepsy, or psychiatric disorders. Regular liver function tests recommended during prolonged use. Not recommended for persons with active depression, anxiety disorders, psychosis, or other major psychiatric disorders. Pregnancy Category C: use during pregnancy only if potential benefit justifies potential risk to fetus.

Contraindications

History of psychiatric disorders including depression, anxiety disorders, psychosis, or suicide attempts. Known hypersensitivity to mefloquine or related compounds. Contraindicated in patients with history of convulsions or epilepsy. Not recommended for persons with cardiac conduction abnormalities or severe hepatic impairment. Avoid use in patients with known mefloquine-associated neurological or psychiatric reactions.

Possible side effects

Common (≥1%): dizziness, headache, sleep disorders, nausea, diarrhea Less common: vivid dreams, visual disturbances, tinnitus, loss of balance Serious (require immediate medical attention): depression, anxiety, paranoia, hallucinations, suicidal thoughts, seizures, severe dizziness Neurological: peripheral neuropathy, encephalopathy, convulsions Cardiac: bradycardia, tachycardia, arrhythmias Dermatological: rash, pruritus, urticaria

Drug interaction

Significant interactions with anticonvulsants (carbamazepine, phenytoin, valproic acid) may reduce seizure threshold. Concurrent use with other antimalarials (particularly chloroquine) may increase risk of convulsions. May potentiate effects of beta-blockers and calcium channel blockers. Rifampin reduces mefloquine concentrations. Avoid concomitant use with drugs that prolong QT interval. Ketoconazole may increase mefloquine concentrations. Use with caution with other neurotoxic drugs.

Missed dose

If a weekly dose is missed, take it as soon as possible, then resume the regular weekly schedule. If less than 2 days remain before the next scheduled dose, skip the missed dose and continue with regular dosing schedule. Do not double doses. For doses missed in malaria-endemic areas, consider additional protective measures against mosquito bites.

Overdose

Symptoms may include exaggerated side effects including nausea, vomiting, dizziness, and neurological symptoms. Severe overdose may cause cardiac arrhythmias, convulsions, and coma. Management includes gastric lavage if presented early, followed by activated charcoal. Cardiac monitoring essential. Symptomatic and supportive treatment. No specific antidote available. Dialysis not effective due to high protein binding.

Storage

Store at controlled room temperature (20-25°C or 68-77°F). Protect from moisture and light. Keep in original blister packaging until use. Keep out of reach of children. Do not use after expiration date printed on packaging. Do not transfer to other containers as moisture protection may be compromised.

Disclaimer

This information is for educational purposes only and does not replace professional medical advice. Prescription and use of Lariam must be under supervision of a qualified healthcare provider. Individual response to medication may vary. Healthcare providers should assess individual risk factors and destination-specific malaria resistance patterns before prescribing. The benefits of malaria prophylaxis must be weighed against potential side effects for each patient.

Reviews

Clinical studies demonstrate Lariam’s efficacy in malaria prevention ranges from 85-95% in various endemic regions. Many travelers report satisfaction with the convenience of weekly dosing. However, reviews are mixed regarding tolerability, with approximately 10-25% of users reporting neuropsychiatric side effects. Military deployment studies show effective protection but note discontinuation rates due to adverse effects. Many infectious disease specialists consider Lariam valuable for specific travel scenarios despite side effect profile, particularly for areas with high chloroquine resistance.