Ask the Experts: Malaria prophylaxis for travelers
Pharmacists should consider several options for treating patients traveling to malarious areas.
Question. I am familiar with the guidelines for malaria prophylaxis for travelers, but can you point me to the guidelines or recommendations on what I should do for patients who were born and have lived in the United States but are moving to live in Santa Cruz, Bolivia, where malaria is endemic and where chemoprophylaxis is recommended for travelers? I am not sure if or what I should do for malaria prophylaxis in these patients.
Answer. An excellent review article on this subject appears in JAMA.1 CDC's Yellow Book, available at cdc.gov/travel, may also provide guidance.
According to malaria surveillance data provided by the medical publisher Shoreland Travax, no malaria occurs within the city of Santa Cruz itself.2 However, if the patient travels outside of the city to more rural areas during the evening or nighttime, then malaria may be of concern. A perfect solution to this issue may not exist, as it will depend on the specific patient, his/her medical and medication history, and the travel destination(s) and plans, but the following options should be considered:
- Continuous antimalarial prophylaxis plus insect repellents/insecticides. Probably the most conservative option, but adverse drug reactions (ADRs) (for antimalarial agents), adherence, and cost may be issues for patients. This probably will not be necessary in this particular patient if he/she is only staying in Santa Cruz.
- Initial antimalarial prophylaxis plus insect repellents/insecticides, followed by emergency self-treatment if needed. This is a less conservative option and involves less concern for ADRs and cost; however, it does allow some continuous coverage while travelers become situated in their living environment and place of accommodation. Self-treatment then could be used if malaria is suspected by the patient, but see item 4 below.
- Insect repellents and insecticides alone. These agents are the only options for the prevention of malaria, as infection cannot be acquired if the patient is not bitten by mosquitoes. Adherence and cost remain issues, primarily if the agents are used long term. This approach may be appropriate for patients who are only traveling periodically to malarious areas from dusk to dawn.
- Self-treatment with atovaquone and proguanil hydrochloride (Malarone—GlaxoSmithKline) or artemether/lumefantrine (Coartem—Novartis). Use of these agents involves even less concern for ADRs, cost, and adherence; however, because symptoms of malaria are often nonspecific and influenza-like in nature, they may be used when symptoms are accidentally mistaken for malaria. Prompt access to care and evaluation is very important, as the patient will need to be evaluated for malaria. This is another option for this patient.
- Primaquine could be used as presumptive self-treatment when/if the patient returns to the United States. This may be useful because Plasmodium vivax predominates in Bolivia, and typically this species has a delayed onset of symptoms due to a longer incubation period in the body. However, G6PD (glucose-6-phosphate dehydrogenase) deficiency testing is required before starting primaquine, as hemolytic anemia may develop in those with such deficiency.
All patients, regardless of destination(s) and travel plans, should check with their health care provider or a travel health specialist before departing for specific advice and recommendations for vaccines and medications for international travel. Several options for malaria chemoprophylaxis exist and include Malarone, mefloquine, chloroquine, and doxycycline. Use of these agents is dependent on where the patient plans to travel, as resistance to these medications may occur in certain parts of the world. Patient-specific medical and medication histories also should be considered when deciding on an antimalarial agent.
Karl Hess, PharmD, FCPhA
Assistant Professor of Pharmacy Practice and Administration
Director, Community Pharmacy Residency Training Program
Certificate in Travel Health (CTH)
College of Pharmacy
Western University of Health Sciences
- Chen LH, Wilson ME, Schlagenhauf P. Prevention of malaria in long-term travelers. JAMA. 2006;296:2234–44.
- Shoreland, Inc. Shoreland/Travax. Accessed at www.travax.com, October 11, 2011.