Mefloquine Shortage: What Providers and Prescribers Need to Know in 2026

The ongoing mefloquine supply shortage presents a clinical challenge for prescribers in travel medicine, primary care, and infectious disease. Since May 2024, Teva Pharmaceuticals USA — the primary U.S. generic manufacturer of mefloquine hydrochloride 250 mg — has reported limited supply. The ASHP drug shortage bulletin, created October 9, 2024, was last updated September 18, 2025, indicating the shortage was not fully resolved within the first year.

This clinical briefing provides guidance on managing affected patients, evidence-based alternatives, special population considerations, and when to escalate to CDC Malaria consultation.

Shortage Status and Clinical Impact

The mefloquine shortage affects only the generic formulation. The brand Lariam was withdrawn from the U.S. market by Roche in August 2009 and is not available domestically. With Teva as the dominant supplier, any production disruption immediately eliminates most of the U.S. supply. The ASHP bulletin advises healthcare professionals to contact the CDC Malaria clinical consult service (cdc-malaria@cdc.gov or 770-488-7788, M-F 9am-5pm EST; after hours: 770-488-7100) to discuss alternatives for specific patient populations.

Which Patients Are Most Clinically Vulnerable to the Shortage?

Most travelers can be transitioned to an appropriate alternative without significant compromise in protection. However, the following populations warrant special consideration:

Pregnant travelers to P. falciparum-endemic regions: Mefloquine is the primary recommended option in pregnancy (when travel cannot be deferred). Doxycycline is contraindicated. Atovaquone-proguanil has limited safety data in pregnancy (generally avoided). Chloroquine is an option only where P. falciparum remains sensitive. These patients may require referral to a maternal-fetal medicine or infectious disease specialist.

Patients with G6PD deficiency: Tafenoquine (Arakoda) is absolutely contraindicated. Chloroquine, mefloquine, and atovaquone-proguanil are generally safe for G6PD-deficient patients. With mefloquine unavailable, atovaquone-proguanil or doxycycline are the recommended alternatives.

Long-term travelers (>6 months) and expatriates: The once-weekly dosing of mefloquine provides superior adherence over extended periods. Daily doxycycline or atovaquone-proguanil regimens carry higher non-adherence risk in long-term travel settings. Consider this when counseling patients.

Patients with contraindications to all alternatives: For complex cases — patients who cannot tolerate doxycycline, atovaquone-proguanil, tafenoquine, or chloroquine — contact CDC Malaria consultation for individualized guidance.

Evidence-Based Alternatives to Mefloquine

Multiple studies have confirmed that atovaquone-proguanil, doxycycline, and mefloquine are equally effective in preventing malaria among short-term travelers when used correctly. The following alternatives are supported by CDC Yellow Book guidance:

Atovaquone-proguanil (Malarone): 250/100 mg daily (adults), starting 1-2 days before travel, continuing during travel, and for 7 days after departure from endemic area. Causal prophylaxis — short post-travel dosing period is a major advantage. Avoid in pregnancy, infants <5 kg, or patients with severe renal impairment (CrCl <30 mL/min).

Doxycycline: 100 mg daily, starting 1-2 days before travel, continuing during travel, and for 4 weeks after return. Cost-effective and broadly effective globally, including Southeast Asia. Contraindicated in pregnancy and children <8 years.

Tafenoquine (Arakoda): Adults only. Loading: 200 mg daily x 3 days; maintenance: 200 mg weekly; terminal dose: 200 mg one week after leaving endemic area. Requires normal G6PD activity testing before use. Not for use in pregnancy or breastfeeding.

Chloroquine: 300 mg base weekly. Reserve for chloroquine-sensitive destinations only (Caribbean, some parts of Central America and the Middle East). Resistance is widespread elsewhere.

Resistance Patterns to Consider When Prescribing Alternatives

Prescribers should consult the current CDC Yellow Book or ASTMH guidelines for the traveler's specific destination(s). Notably:

Chloroquine-resistant P. falciparum is found across most of sub-Saharan Africa, Southeast Asia, and South America — do not use chloroquine for these destinations.

Mefloquine resistance is prevalent in the Greater Mekong Subregion (Thailand-Myanmar border, Cambodia, Vietnam, Laos) — atovaquone-proguanil or doxycycline are preferred for Southeast Asia regardless of the shortage.

Mefloquine remains effective in most of sub-Saharan Africa, the Indian subcontinent, and Central and South America outside of areas with documented mefloquine resistance.

Where to Source Mefloquine During the Shortage

When a patient specifically requires mefloquine (e.g., pregnant traveler), the following sourcing approaches may help:

Contact travel health clinics and hospital outpatient pharmacies — these facilities often have dedicated antimalarial stock.

Contact major wholesalers (McKesson, AmerisourceBergen, Cardinal Health) to check current availability through alternative distributors.

Encourage patients to use medfinder — the service calls pharmacies on the patient's behalf to find current mefloquine availability, saving time for both the patient and your office staff.

Call CDC Malaria consultation at 770-488-7788 for complex cases and guidance on specialty sourcing options.

Documentation and Patient Communication

Document the shortage and alternative prescribing rationale in the patient's chart. Ensure patients understand the importance of starting their antimalarial on the correct schedule regardless of which medication is prescribed. For providers who frequently encounter patients struggling to fill specialty medications, medfinder for providers offers a streamlined way to help patients find their prescriptions in stock.