Infectious Disease · Medications

When we develop an infection, the treatment we need depends largely on what is causing the infection. Bacteria, fungi, and parasites are different types of organisms, so they require different types of medicines.

Three important categories of anti-infective medicines are antibiotics, antifungals, and antiparasitics, with antivirals forming a fourth, separate category. Although these medications all help fight infections, they target different organisms and treat different conditions.

Understanding the differences between antibiotics, antifungals, and antiparasitics can help explain why a medication prescribed for one infection may be ineffective against another.

Antibiotics: Treating Bacterial Infections

Antibiotics treat bacterial infections. They work by killing bacteria or preventing them from growing and multiplying.

However, antibiotics do not work against viruses. Common viral illnesses such as colds and influenza do not improve with antibiotics. In some cases, though, a viral infection can lower the body's immunity, allowing invading bacteria to take over and cause a secondary infection. Consult your healthcare provider for appropriate treatment. (1,2)

Antibiotic resistance. One major concern surrounding antibiotic use is antimicrobial resistance. Resistance occurs when microorganisms change in ways that allow them to survive drugs that previously worked against them. Use antibiotics only when indicated. (3,4)

Antifungals: Treating Fungal Infections

Where antibiotics target bacteria, antifungal medicines treat fungal infections. Fungal infections can affect the skin, mouth, genital area, nails, lungs, bloodstream, and other parts of the body.

For example, ringworm is a fungal infection of the skin, hair, or nails and is typically treated with an antifungal medication. Depending on the infection's location and severity, treatment may be applied directly to the affected area or taken orally. (5,6)

Candidiasis is another common fungal infection. Candida yeasts primarily cause it, and it can occur in the mouth, vagina, skin, esophagus, or bloodstream. (6)

Antiparasitics: Treating Parasitic Infections

Antiparasitic medicines treat parasite infections. Parasites are organisms that live in or on a host and obtain nutrients at the host's expense.

Parasites can be transmitted in several ways, including contaminated food or water, insects, animals, or other exposures. Parasitic diseases include infections caused by worms and microscopic parasites called protozoa. (7)

The appropriate drug depends on the specific parasite involved. For example, malaria requires specific antimalarial medicines (9), while different intestinal parasites may require entirely different medications. (7)

Antivirals: A Separate Category

Just as antibiotics do not treat viral infections such as the common cold or influenza, the medicines above are not designed for viruses. Antiviral medicines are effective against infections such as influenza and COVID-19, and work best when treatment begins soon after symptoms appear. Having early access to these antiviral drugs can help lessen the severity of the illness. (8)

How Are Antibiotics, Antifungals, and Antiparasitics Different?

The easiest way to understand the difference is to consider what organism the medicine targets.

Although these medications all fight infections, you generally cannot substitute one for another. There are exceptions, though. Metronidazole, for example, can be used as either an antibiotic or an antiparasitic.

Why Correct Diagnosis Matters

Because each class of medicine works only against its target organism, identifying the cause of an infection comes first. Symptoms alone do not always reveal an infection's cause. A cough, rash, diarrhea, fever, or sore throat can have multiple possible causes.

For this reason, healthcare professionals consider a person's symptoms, medical history, physical examination, travel or exposure history, and laboratory testing when determining the cause of an infection.

Choosing the right medicine is important for treating an illness. The wrong antimicrobial may not help and could still cause unwanted side effects. Using antimicrobials when they are not needed can also lead to drug resistance, making some infections harder to treat.

Being Prepared Before Illness Strikes

Getting the right medicine quickly, and with a professional's guidance, is where preparation pays off. TWC's Contagion Emergency Kit is built for viral respiratory illness such as COVID and influenza, pairing antiviral and antibiotic medications that target respiratory illnesses with a nebulizer to relieve respiratory symptoms. The Medical Emergency Kit covers a broader range, from tick bites to skin and urinary tract infections to yeast and other fungal infections, along with antibiotics and anti-nausea medication for food poisoning.

Each kit comes with a virtual consultation with a qualified healthcare professional, so the right medicine is matched to the right cause. Having both on hand could save you travel time to the clinic or hospital, exposure to other pathogens in the waiting room, and money. By being proactive, early intervention could help you avoid a trip to the emergency room.

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Medical Emergency Kit · Prescription Bundle

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TWC's Medical Emergency Kit pairs a licensed provider consultation with eight prescription medications in one shipment, including an antibiotic, an antifungal, and an antiparasitic covered in this guide, plus additional antibiotics and anti-nausea medication. Every prescription ships from a U.S. pharmacy, with replenishment eligibility for up to two years.

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This content is for information only and not intended as medical advice. Consult with your care provider for diagnosis and treatment of any infection.