Dicloxacillin is a prescription medication used to treat bacterial infections throughout the body. It belongs to the penicillin class of antibiotics, designed to kill susceptible bacteria. This drug is generally taken orally. Using dicloxacillin when it is not needed can increase the risk of developing future infections that are resistant to antibiotic treatment.
How Dicloxacillin Works
Dicloxacillin is classified as a narrow-spectrum, beta-lactam antibiotic, specifically grouped as a penicillinase-resistant penicillin. Its mechanism of action involves interfering with the bacteria’s ability to construct a stable cell wall. It works by binding to specific proteins, inhibiting the final stage of cell wall synthesis and leading to the death of the bacterial cell.
Many bacteria, particularly Staphylococcus species, produce an enzyme called penicillinase. This enzyme breaks down and inactivates standard penicillin antibiotics. Dicloxacillin’s molecular structure allows it to remain stable and functional in the presence of this enzyme, enabling it to fight bacteria that have evolved resistance to earlier penicillins.
Specific Infections Treated
Dicloxacillin is primarily indicated for treating mild-to-moderate infections caused by penicillinase-producing bacteria. The main target is methicillin-sensitive Staphylococcus aureus (MSSA), a common type of staph bacteria.
The drug is frequently used for various skin and soft tissue infections, including cellulitis, impetigo, boils, and abscesses. Dicloxacillin is also a preferred treatment option for mastitis (an infection of the breast tissue). Additionally, it may be used as an adjunct treatment for more serious conditions like pneumonia, osteomyelitis, and septic arthritis, when the cause is a susceptible organism.
Guidelines for Taking the Medication
To ensure maximum absorption, dicloxacillin must be taken on an empty stomach. This means taking the medication at least one hour before eating a meal or two hours after. Taking it with food significantly reduces the amount of the drug the body absorbs, decreasing its ability to fight the infection.
The medication is prescribed four times a day, or every six hours, to maintain a consistent concentration of the drug in the body. It is important to take the doses at evenly spaced times each day to optimize the antibacterial action. Patients must complete the full course of treatment, even if their symptoms begin to improve quickly. Stopping the medication too soon can allow the remaining bacteria to survive, potentially leading to a return of the infection and increasing the risk of antibiotic resistance.
Common Side Effects and Allergy Warnings
Like all antibiotics, dicloxacillin can cause a range of side effects, most commonly involving the gastrointestinal system. Patients frequently report symptoms such as nausea, vomiting, or diarrhea. These effects are generally mild and may subside as the body adjusts to the medication.
A more serious concern is the risk of a severe allergic reaction, which can occur with any penicillin-class drug. Signs of a severe allergy include hives, difficulty breathing, wheezing, or swelling of the face, tongue, or throat, and require immediate medical attention. Dicloxacillin use can also disrupt the natural balance of bacteria in the gut, which sometimes leads to an overgrowth of a bacterium called Clostridium difficile. This overgrowth can cause severe, watery, or bloody diarrhea, a condition known as C. difficile-associated diarrhea, which may occur even weeks or months after the antibiotic course is finished.