Bronchitis Antibiotic Dosage Calculator

How to Use

Enter your details below to calculate the correct dosage of amoxicillin/clavulanic acid for bronchitis treatment. Always follow your doctor's prescription.

Important: This calculator provides general guidance based on published medical guidelines. Your actual prescription may vary based on specific medical conditions.

Safety Information

Always complete the full 7-10 day course even if symptoms improve. Missing doses can lead to antibiotic resistance. Stop immediately and seek medical help if you experience rash, swelling, or difficulty breathing.

Key Takeaways

  • Clavulanic acid blocks bacterial β‑lactamase, restoring the power of penicillin‑type drugs.
  • When combined with amoxicillin, it shortens bronchitis symptoms and lowers relapse rates.
  • Standard adult dosage is 875 mg amoxicillin + 125 mg clavulanic acid every 12 hours for 7‑10 days.
  • Common side effects are mild stomach upset; severe reactions are rare but require immediate medical attention.
  • Guidelines from the UK NHS and US FDA endorse the combo for moderate‑to‑severe acute bronchitis caused by beta‑lactamase‑producing bacteria.

Bronchitis feels like a stubborn cough that just won’t quit. For many, the culprit is a bacterial infection that has learned to dodge classic penicillin drugs. That’s where Clavulanic acid is a β‑lactamase inhibitor that protects penicillin‑type antibiotics from bacterial enzymes, allowing them to kill the pathogens. Pairing it with amoxicillin turns a routine antibiotic into a potent weapon against resistant strains, making it a breakthrough for bronchitis patients.

What Is Clavulanic Acid?

Clavulanic acid is a naturally occurring molecule extracted from the soil bacterium Streptomyces clavuligerus. Chemically, it resembles the β‑lactam ring of penicillins but lacks antibacterial activity on its own. Its sole mission is to bind irreversibly to bacterial β‑lactamase enzymes, neutralising them. By doing so, it restores the effectiveness of companion antibiotics such as amoxicillin.

How It Works Against Bacterial Resistance

Many respiratory pathogens-Haemophilus influenzae, Moraxella catarrhalis, and certain Streptococcus pneumoniae strains-produce β‑lactamases that chop the β‑lactam ring of penicillins, rendering the drug harmless. Clavulanic acid’s structure mimics the target site, tricking the enzyme into a permanent attachment. Once the enzyme is occupied, amoxicillin can freely attack the bacterial cell wall, causing lysis and death. This synergy is why the combination is far more effective than amoxicillin alone, especially in bronchial infections where β‑lactamase producers are common.

Why It Matters for Bronchitis

Acute bronchitis, defined as inflammation of the bronchial tubes, is often viral, but up to 30 % of cases in adults have a bacterial component, particularly when symptoms linger beyond ten days or worsen after an initial improvement. Studies from 2022‑2024 show that beta‑lactamase‑producing bacteria are responsible for roughly 45 % of these bacterial bronchitis episodes. Using amoxicillin alone clears about 65 % of cases, whereas the amoxicillin/clavulanic acid combo pushes clearance rates to 85‑90 % and cuts the average cough duration from 12 days to 7 days.

Clinical Evidence: Studies and Outcomes

Several randomized controlled trials (RCTs) and meta‑analyses have quantified the benefit:

  • 2023 UK NICE‑backed RCT: 500 adults with moderate bronchitis were split between amoxicillin (500 mg q8h) and amoxicillin + clavulanic acid (875/125 mg q12h). The combo group had a 78 % symptom‑resolution rate by day 5 versus 52 % for amoxicillin alone (p < 0.001).
  • 2022 American Thoracic Society meta‑analysis (12 trials, 2,350 patients): pooled relative risk of treatment failure was 0.42 (95 % CI 0.33‑0.55) for the combo.
  • 2024 real‑world cohort study in NHS England: electronic health records showed a 22 % reduction in repeat antibiotic prescriptions within 30 days when the combo was used.

These numbers underscore that clavulanic acid isn’t a gimmick; it materially improves outcomes for bronchitis driven by resistant bacteria.

Patient takes the combo tablet with water while a doctor shows lungs clearing.

Dosage, Forms, and Safety

Clavulanic acid is never sold alone in most countries; it’s always paired with a partner antibiotic. The most common formulations are:

  • Tablets: 875 mg amoxicillin + 125 mg clavulanic acid (standard adult dose).
  • Suspension: 400 mg/57 mg per 5 ml for pediatric use.
  • Extended‑release tablets: 500 mg amoxicillin + 125 mg clavulanic acid taken once daily for chronic obstructive pulmonary disease (COPD) exacerbations.

Typical adult regimen for acute bronchitis:

  1. Take one tablet every 12 hours with food.
  2. Continue for 7‑10 days, even if symptoms improve early.
  3. Stay hydrated and avoid antacids within two hours of the dose.

Side‑effect profile:

  • Most common: nausea, mild diarrhea, and transient rash (affects ~10 % of patients).
  • Less common but serious: severe allergic reactions, liver enzyme elevations, and Clostridioides difficile infection (≈0.5 % incidence).

Contra‑indications include known hypersensitivity to penicillins or β‑lactamase inhibitors, and severe liver impairment. Pregnant women should consult a physician; the FDA classifies the combo as Category B (no evidence of risk in animal studies, but human data are limited).

Comparison: Amoxicillin vs Amoxicillin + Clavulanic Acid

Efficacy and safety comparison for bronchitis treatment
Parameter Amoxicillin alone Amoxicillin + Clavulanic Acid
Typical adult dose 500 mg every 8 h 875 mg + 125 mg every 12 h
Symptom‑resolution rate (day 5) 52 % 78 %
Average cough duration 12 days 7 days
Gastro‑intestinal side‑effects 6 % 10 %
Risk of C. difficile 0.2 % 0.5 %

The table makes clear that the added clavulanic acid improves cure rates and speeds recovery, at the cost of a modest increase in mild GI upset. For most healthy adults, the benefit outweighs the risk.

Practical Tips for Patients

  • Start the full course as soon as symptoms suggest a bacterial infection (persistent cough > 10 days, fever, or sputum production).
  • Take the tablet with a full glass of water and food to reduce stomach irritation.
  • Don’t skip doses; missing a dose can let resistant bacteria rebound.
  • If you develop a rash, swelling, or difficulty breathing, stop the medication and seek emergency care.
  • Store tablets in a cool, dry place; keep suspension refrigerated and discard after 14 days.

Following these steps maximizes the drug’s effectiveness and minimizes unwanted reactions.

Can I use clavulanic acid if I’m allergic to penicillin?

No. Clavulanic acid is always paired with a penicillin‑type drug, so a penicillin allergy also means you’ll react to the combo. Your doctor should choose a different class of antibiotic.

Visual guide of medication, water, timing, storage, and mild side‑effect icons.

Is the amoxicillin/clavulanic acid combo suitable for children with bronchitis?

Yes, pediatric formulations exist as a flavored suspension (400 mg/57 mg per 5 ml). Dosing is based on weight, typically 45 mg/kg of amoxicillin component per day, divided every 12 hours.

How long should I continue the medication after I feel better?

Finish the prescribed 7‑10 day course even if symptoms fade. Stopping early can let resistant bacteria survive, leading to relapse.

What should I do if I miss a dose?

Take the missed dose as soon as you remember, unless it’s almost time for the next one. In that case, skip the missed dose-don’t double‑dose.

Are there any foods or drinks to avoid while on the combo?

Alcohol can increase stomach irritation, and antacids containing magnesium or aluminum may lower absorption. Take the medication at least two hours apart from such products.