Infection-related Medicines

Infection-related treatments in primary care

“Infection” is a broad term. In primary care, treatment decisions depend on what type of infection is likely, where it is in the body, and how unwell someone feels.

The most important distinction is the cause:

• Bacterial infections may benefit from antibiotics in selected cases
• Fungal infections are treated with antifungals
• Viral infections usually improve with supportive care, with antivirals used only for specific conditions and situations

Many common infections settle without prescription medication. A key part of safe GP care is deciding when medicines are likely to help, and when they may cause more harm than benefit.

For more condition-specific guidance, you can also explore our Common Infections hub.

Why accurate diagnosis matters

Different infections can look and feel similar, but require different treatments. This is particularly important with skin symptoms, where rashes and infections often overlap.

For example:

• Eczema and fungal rashes can look similar, but steroid-only treatment may worsen fungal infection
• Bacterial skin infections may require topical or oral antibiotics, depending on severity
• Viral rashes do not improve with antibiotics

In remote care, good-quality photos and a clear history help a GP decide whether supportive care, a topical treatment, an oral treatment, or urgent assessment is most appropriate.

For more skin-focused guidance, see: Skin infections.

Antibiotics

Antibiotics treat bacterial infections. They do not treat viruses such as colds, flu, or most sore throats.

Common primary care reasons antibiotics are considered include:

• Skin infection (impetigo, cellulitis)
• Urinary tract infection
• Chest infection in selected cases
• Sinus infection in selected cases
• Dental infections, usually dental-led
• Certain sexually transmitted infections, via appropriate pathways

Topical vs Oral Antibiotics

Topical antibiotics are used for small, localised skin infections, often alongside hygiene measures.
Examples include: fusidic acid (short courses only where appropriate).

Oral antibiotics are used when infection is more widespread, spreading, painful, recurrent, or associated with systemic symptoms.
Common examples used in primary care include: flucloxacillin, phenoxymethylpenicillin (penicillin V), doxycycline, clarithromycin, co-amoxiclav, nitrofurantoin (for UTI), and trimethoprim in selected cases.

Learn more: UTI / Cystitis Treatment Online

Choice depends on likely source of infection, commons, suspected or confirmed organisms, allergy status, pregnancy status, local resistance patterns, and infection severity.

Antibiotic Stewardship

Not prescribing an antibiotic can be the safest option when:

• Symptoms suggest a viral illness
• There is no evidence of bacterial infection
• Risks of side effects outweigh benefit
• Infection is likely to settle with supportive care

Antibiotics can cause side effects including diarrhoea, thrush, rash, and rarely more severe reactions. They can also disrupt normal gut bacteria.

Read more: Antibiotics and Responsible Prescribing

Antifungal Medicines

Antifungals treat fungal skin, scalp, and nail infections. These infections are common and often persistent without the right treatment.

Topical Antifungals

Topical antifungals are first-line for many localised infections.

Common examples include:

• clotrimazole
• miconazole
• terbinafine
• ketoconazole (often for seborrhoeic dermatitis and certain yeast-related rashes)

Typical uses include:

• Athlete’s foot (tinea pedis)
• Groin rash (tinea cruris)
• Ringworm (tinea corporis)
• Yeast-related skin fold rashes
• Certain scalp conditions, with medicated shampoos in selected cases

Important point: topical steroids can reduce redness and itch but may allow fungal infection to spread if used without antifungal treatment.

Oral Antifungals

Oral antifungals are usually considered when infection is:

• Extensive
• Involving the scalp
• Affecting nails
• Recurrent or not responding to topical treatment

Common examples include:

• terbinafine
• itraconazole
• fluconazole in selected cases

Oral antifungals can interact with other medicines and may require clinical review, particularly in people with liver disease or complex medical histories.

Antiviral Medicines

Most viral infections do not require antiviral medication. However, antivirals are sometimes used when started early for specific conditions.

Examples used in primary care include:

• aciclovir for shingles, cold sores, and some herpes infections
• valaciclovir as an alternative in selected cases

Antivirals are usually most helpful when started promptly and are considered more strongly in higher-risk situations, such as severe symptoms, facial involvement, or immunosuppression.

Skin Infections by Type

Bacterial Skin Infections

Common examples:

• Impetigo: crusting lesions, often around nose and mouth
• Cellulitis: hot, red, painful spreading skin infection
• Folliculitis: infected hair follicles, sometimes recurring
• Infected eczema: weeping, crusting, increased pain or worsening inflammation

Bacterial infections may require topical or oral antibiotics depending on severity. Spreading infection, fever, rapidly worsening pain, or facial involvement should be assessed urgently.

Fungal Skin Infections

Common examples:

• Athlete’s foot
• Groin rash
• Ringworm
• Yeast-related skin fold rash

Fungal infections often need antifungal treatment for an adequate duration to prevent recurrence. If a rash worsens with steroid use, fungal infection should be reconsidered.

Viral Skin Infections

Common examples:

• Cold sores (herpes simplex)
• Shingles (herpes zoster)
• Viral warts, molluscum

Antibiotics do not treat viral rashes. Treatment is often supportive, although antivirals may be used for shingles or significant herpes symptoms in selected cases.

Topical Treatments That Support Infection Care

Depending on the condition, supportive topical measures may include:

• Emollients for eczema-prone skin
• Antiseptic washes or creams in selected minor infections
• Barrier creams for skin fold irritation
• Medicated shampoos for scalp involvement

These can reduce irritation and support healing, but they do not replace targeted treatment when infection is clearly present.