Relapsing fever is a bacterial infection characterized by recurrent episodes of fever, chills, headache, muscle pain, and other flu-like symptoms. This illness is typically caused by certain types of bacteria, primarily from the genus Borrelia, which are transmitted through vectors like lice or ticks. The hallmark of relapsing fever is its cyclic nature, with fevers subsiding for a period only to return multiple times if untreated.

The primary treatment for relapsing fever is doxycycline, an antibiotic that belongs to the tetracycline class. Doxycycline works by inhibiting the bacteria's ability to produce proteins essential for their survival, effectively stopping their growth and leading to bacterial cell death. This antibiotic is widely effective against the bacteria responsible for relapsing fever and is considered a first-line treatment.

Doxycycline not only treats the symptoms by eliminating the bacterial infection but also reduces the risk of complications associated with relapsing fever. It is important to start treatment as soon as relapsing fever is diagnosed to prevent prolonged illness and minimize the risk of recurrent episodes.

Dosage for Doxycycline in Treating Relapsing Fever

For Adults:

• Doxycycline: 100 mg taken twice daily for 7–10 days. It is generally recommended to take the medication with a full glass of water and to avoid lying down for at least 30 minutes afterward to reduce the risk of esophageal irritation.

For Children:

• Children aged 8 and older (weighing less than 45 kg): 2.2 mg/kg twice daily for 7–10 days.
• Children weighing 45 kg or more: Dosage may follow adult guidelines (100 mg twice daily) under medical supervision.

Note: Doxycycline is typically not recommended for children under 8 years old due to the risk of permanent tooth discoloration and potential impacts on bone growth, except when benefits outweigh risks.

Important Considerations

While doxycycline is effective, it should be taken as prescribed for the full course, even if symptoms resolve before the treatment is complete. Stopping early can lead to incomplete eradication of bacteria, increasing the risk of relapse. Doxycycline may cause photosensitivity, so it’s recommended to avoid prolonged sun exposure and use sun protection when outdoors.

Additionally, doxycycline can interact with certain supplements and medications, especially antacids, calcium, and iron, which can decrease its absorption. To ensure optimal effectiveness, take doxycycline 1–2 hours before or after consuming these substances.