| Medication: Mefloquine | Medication Information and Guidelines |
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| Recommended Dose and Dosage Regimen | The recommended dose of mefloquine for the prevention and treatment of malaria varies depending on several factors, including the patient’s age, weight, destination, and individual susceptibility to malaria. For malaria prophylaxis in adults, the typical dose is 250 mg (one tablet) once weekly, initiated 1 to 2 weeks before travel to a malaria-endemic area and continued throughout the stay and for 4 weeks after leaving the area. For children, the dosage is based on body weight and is calculated accordingly. For the treatment of uncomplicated malaria, the recommended adult dose is an initial loading dose of 750 mg (three tablets) followed by 500 mg (two tablets) 6 to 12 hours later, then 500 mg (two tablets) once daily for a total of three days. Pediatric dosing for the treatment of malaria is based on weight and is determined by a healthcare provider. Follow the specific dosing regimen prescribed by your healthcare provider and the manufacturer’s instructions for optimal efficacy and safety. |
| Frequency of Administration | Mefloquine is typically administered orally as a once-weekly dose for malaria prophylaxis or in divided doses for the treatment of malaria, as directed by a healthcare provider. For prophylaxis, mefloquine should be taken at the same time each week, preferably with food or a milky drink to enhance absorption and minimize gastrointestinal side effects. For the treatment of malaria, the initial loading dose may be followed by additional doses spaced 6 to 12 hours apart, depending on the severity of the infection and the patient’s response to therapy. |
| Route of Administration | Mefloquine is administered orally in the form of tablets for both malaria prophylaxis and treatment. The tablets should be swallowed whole with a full glass of water, preferably with food or a milky drink to aid absorption and reduce the risk of gastrointestinal upset. Avoid chewing or crushing the tablets, as this may affect drug absorption and efficacy. Follow the package instructions and your healthcare provider’s recommendations for proper administration of mefloquine. |
| Mechanism of Action (MOA) | Mefloquine is a synthetic antimalarial agent that acts primarily by inhibiting the growth and replication of Plasmodium parasites, the causative agents of malaria. The exact mechanism of action involves interference with the parasite’s ability to utilize hemoglobin for energy metabolism and disrupts multiple stages of the parasite’s life cycle, including intraerythrocytic development and hepatic schizogony. Mefloquine exhibits concentration-dependent antimalarial activity against susceptible Plasmodium species, including Plasmodium falciparum and Plasmodium vivax, leading to parasite death and clinical resolution of malaria infections. |
| Pharmacokinetics (PK) | Mefloquine is well absorbed after oral administration, with peak plasma concentrations achieved within 6 to 24 hours. The drug is extensively distributed throughout the body, including the liver, spleen, and adipose tissue, with a large volume of distribution and long elimination half-life. Mefloquine undergoes extensive hepatic metabolism via cytochrome P450 enzymes, primarily CYP3A4, to form active and inactive metabolites. The elimination half-life of mefloquine is approximately 2 to 4 weeks, leading to prolonged drug exposure and prophylactic efficacy following a single dose. Mefloquine and its metabolites are primarily excreted in the bile and feces, with minimal renal elimination. |
| Pharmacodynamics (PD) | Mefloquine exerts its pharmacodynamic effects by interfering with essential metabolic pathways and cellular processes in Plasmodium parasites, leading to parasite death and clearance from the bloodstream. The drug acts primarily on the erythrocytic stage of the malaria parasite’s life cycle, where it inhibits hemoglobin degradation and heme detoxification, resulting in toxic heme accumulation and oxidative damage to the parasite. Mefloquine also disrupts the development and maturation of Plasmodium parasites in the liver, preventing the establishment of a systemic infection and reducing the risk of clinical malaria. |
| Pathophysiology | Mefloquine is indicated for the prevention and treatment of malaria, a life-threatening infectious disease caused by Plasmodium parasites transmitted through the bite of infected Anopheles mosquitoes. Malaria is characterized by fever, chills, headache, myalgia, and other systemic symptoms, with severe complications such as cerebral malaria, severe anemia, and multiorgan dysfunction in untreated or inadequately treated cases. Mefloquine therapy aims to prevent malaria infection in travelers to endemic areas and provide rapid and effective treatment for acute malaria episodes, thereby reducing morbidity, mortality, and disease transmission. |
| Primary Indications | Prevention and treatment of malaria caused by susceptible Plasmodium parasites, including Plasmodium falciparum and Plasmodium vivax. |
| Contraindications | Contraindications to mefloquine use include hypersensitivity to mefloquine or related compounds, a history of psychiatric disorders (e.g., depression, anxiety, psychosis), active seizures or a history of epilepsy, cardiac conduction abnormalities (e.g., prolonged QT interval), and concomitant use of drugs known to prolong the QT interval or potent CYP3A4 inhibitors. Mefloquine should not be used in patients with severe hepatic impairment or preexisting neuropsychiatric conditions, as it may exacerbate these conditions or increase the risk of adverse effects. Avoid mefloquine use in pregnant women unless the potential benefits outweigh the risks to the fetus. |
| Purpose of Taking Medication | The purpose of mefloquine therapy is to prevent malaria infection in travelers visiting endemic areas and to treat acute malaria episodes in affected individuals. Mefloquine is used as a prophylactic agent to provide long-term protection against malaria transmission and as a therapeutic option to rapidly eliminate Plasmodium parasites from the bloodstream and prevent disease progression in symptomatic patients. |
| Usage Instructions | Take mefloquine tablets orally with a full glass of water, preferably with food or a milky drink to enhance absorption and minimize gastrointestinal side effects. For malaria prophylaxis, initiate treatment 1 to 2 weeks before travel, continue once weekly throughout the stay in a malaria-endemic area, and for 4 weeks after leaving the area. For the treatment of acute malaria, follow the dosing regimen prescribed by your healthcare provider, including the initial loading dose and subsequent maintenance doses spaced at specified intervals. |
| Precautions and Care | Patients taking mefloquine should be advised to report any new or worsening symptoms, including mood changes, anxiety, insomnia, nightmares, or seizures, to their healthcare provider promptly. Use caution when prescribing mefloquine in patients with a history of neuropsychiatric disorders, cardiac conduction abnormalities, or seizures, as mefloquine may exacerbate these conditions or increase the risk of adverse effects. Discontinue mefloquine and seek medical attention if signs of severe or persistent adverse effects occur during therapy. |
| Dietary Considerations | There are no specific dietary considerations associated with mefloquine use. Maintain a balanced diet and adequate hydration to support overall health and well-being during travel to malaria-endemic areas and throughout the course of mefloquine prophylaxis or treatment. Avoid excessive consumption of alcohol or other substances that may interfere with drug absorption, metabolism, or efficacy. |
| Missed Dose | If a dose of mefloquine is missed, take it as soon as remembered, unless it is almost time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed one. Continue taking mefloquine as prescribed to maintain optimal prophylactic or therapeutic efficacy against malaria infection. |
| Possible Side Effects | Common side effects of mefloquine may include gastrointestinal disturbances (e.g., nausea, vomiting, diarrhea), headache, dizziness, fatigue, and sleep disturbances (e.g., vivid dreams, insomnia). Less common side effects may include neuropsychiatric symptoms (e.g., mood changes, anxiety, depression), seizures, and cardiac conduction abnormalities. Rare but serious adverse effects may include severe neuropsychiatric reactions (e.g., psychosis, suicidal ideation), arrhythmias, and allergic reactions. Contact your healthcare provider if you experience severe or persistent side effects while taking mefloquine. |
| Storage and Disposal | Store mefloquine tablets at room temperature away from moisture, heat, and light. Keep the medication out of reach of children and pets. Unused or expired mefloquine should be disposed of properly according to local regulations or guidelines for pharmaceutical waste disposal. |
| Overdose or Emergency | In case of mefloquine overdose or emergency, seek medical attention or contact a poison control center immediately. Overdose may lead to symptoms such as nausea, vomiting, dizziness, or seizures. Treatment of mefloquine overdose is supportive and symptomatic, with monitoring of vital signs and neurological status as needed. |
| Monitoring and Laboratory Tests | Patients receiving mefloquine prophylaxis or treatment should undergo regular monitoring for clinical symptoms, treatment response, and adverse effects throughout the course of therapy. Monitor for signs of malaria infection, including fever, chills, headache, myalgia, and other systemic symptoms, especially during travel to malaria-endemic areas and after returning from travel. Additional laboratory tests, including blood smears and polymerase chain reaction (PCR) assays, may be indicated to confirm malaria diagnosis and assess treatment efficacy in symptomatic patients. |
Important Note: Always consult with a healthcare professional for personalized medical advice and guidance regarding the use of given drug, especially regarding dosing, administration, and potential side effects. Your healthcare provider can provide tailored recommendations based on your individual medical history, current medications, and specific treatment needs. Never self-adjust your given drug regimen or discontinue treatment without first consulting your healthcare provider. If you have any questions or concerns about given drug or its use, talk to your doctor or pharmacist for further information and assistance.