Home Drug Guide Mefloquine Hydrochloride

Drug Guide

Generic Name

Mefloquine Hydrochloride

Brand Names Lariam

Classification

Therapeutic: Antimalarial Agent

Pharmacological: Amino Alcohol Antimalarial

FDA Approved Indications

  • Prevention and treatment of malaria caused by Plasmodium falciparum, P. vivax, P. malariae, and P. ovale

Mechanism of Action

Mefloquine disrupts the parasite's ability to detoxify heme into non-toxic hemozoin, accumulating toxic heme within the parasite and leading to its death.

Dosage and Administration

Adult: Prevention: 250 mg once weekly starting 2-3 weeks before travel, continuing during travel and for 4 weeks after leaving endemic area. Treatment: 750 mg as a single dose, followed by 250 mg in 6-8 hours and 250 mg after 24 hours.

Pediatric: Dose based on weight, typically 25-50 mg/kg divided over the dosing period.

Geriatric: Use with caution; dose adjustments based on renal and hepatic function.

Renal Impairment: No specific adjustment, but caution advised due to drug accumulation risk.

Hepatic Impairment: Use with caution; extensive hepatic metabolism requires caution in hepatic impairment.

Pharmacokinetics

Absorption: Well absorbed orally, with high bioavailability.

Distribution: Widely distributed; crosses blood-brain barrier and placental barrier.

Metabolism: Primarily hepatic via CYP3A4 enzymes.

Excretion: Excreted mainly in feces, some in urine.

Half Life: approximately 2-4 weeks, which is unusually long.

Contraindications

  • History of hypersensitivity to mefloquine or related compounds.
  • History of seizures, neuropsychiatric disorders, or cardiac conduction abnormalities.

Precautions

  • Use cautiously in persons with psychiatric disorders, cardiac conduction issues, or concomitant use of drugs affecting QT interval.
  • Monitor for neuropsychiatric and cardiac side effects.

Adverse Reactions - Common

  • Nausea, vomiting, diarrhea (Common)
  • Dizziness, headache (Common)
  • Vivid dreams, insomnia (Common)

Adverse Reactions - Serious

  • Neuropsychiatric reactions (e.g., anxiety, paranoia, hallucinations) (Rare but serious)
  • Seizures (Rare)
  • QRS prolongation and QT interval prolongation, arrhythmias (Rare)

Drug-Drug Interactions

  • Alcohol, other neurotoxic drugs, cardiac QT prolonging drugs

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for neuropsychiatric symptoms, cardiac function (ECG if indicated), and ongoing assessment of mental status.

Diagnoses:

  • Risk for neuropsychiatric disturbances
  • Risk for cardiac arrhythmias

Implementation: Educate patient on potential side effects, advise on avoiding driving or operating heavy machinery if dizziness or neuropsychiatric symptoms occur.

Evaluation: Assess for emergence of adverse effects, ensure adherence, and monitor for symptom resolution.

Patient/Family Teaching

  • Inform about possible neuropsychiatric effects and to report any mood changes or hallucinations immediately.
  • Advise to avoid alcohol and other neurotoxic substances during therapy.
  • Instruct on importance of adherence to dosing schedule.

Special Considerations

Black Box Warnings:

  • Neuropsychiatric adverse reactions, including depression, hallucinations, psychosis, and suicidal thoughts.

Genetic Factors: Genetic sensitivity to neuropsychiatric side effects not fully understood.

Lab Test Interference: None significant.

Overdose Management

Signs/Symptoms: Nausea, vomiting, dizziness, neuropsychiatric disturbances, seizures, cardiac arrhythmias.

Treatment: Supportive therapy, cardiac monitoring, and seizure management as needed. No specific antidote.

Storage and Handling

Storage: Store at room temperature, protected from moisture and light.

Stability: Stable under recommended storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.