Generic name: Clarithromycin

Biaxin is an antibiotic that is used to treat various types of infections. It belongs to a class of drugs known as macrolide antibiotics. Biaxin works by killing bacteria or preventing their growth.

Biaxin is available in tablet and suspension form. It should be taken with food.

Take Biaxin exactly as prescribed by your doctor. Do not take it in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Shake the oral suspension well just before you measure a dose. To be sure you get the correct dose, measure the suspension with a marked measuring spoon or medicine cup.

Do not take this medicine with milk or other dairy products. They could make the antibiotic less effective.

Take Biaxin for the entire length of time prescribed by your doctor. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Biaxin will not treat a viral infection such as the common cold or flu.

Call your doctor if your symptoms do not improve, or if they get worse while you are taking Biaxin. Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.


Biaxin is rapidly absorbed after oral administration. The mean peak plasma concentration (Cmax) of clarithromycin occurs approximately 2 to 3 hours following administration of a 250 mg dose, and 3 to 4 hours following administration of a 500 mg dose. In healthy young adults (n=14), the mean peak plasma concentration was 1.6 ± 0.5 mcg/mL following administration of 250 mg BIAXIN, and 2.2 ± 0.7 mcg/mL following administration of 500 mg BIAXIN. In general, the extent of absorption decreases with increasing dose.

The bioavailability of clarithromycin suspension is similar to that of clarithromycin tablets under fasting conditions. However, following administration of clarithromycin suspension to fasting subjects, peak plasma concentrations were achieved earlier (1 hour) than with the tablet formulation. The mean Cmax was 1.5 ± 0.6 mcg/mL and 2.0 ± 1.0 mcg/mL following administration of 250 mg clarithromycin suspension and 500 mg clarithromycin suspension, respectively.

The bioavailability of BIAXIN Filmtabs (500 mg twice daily for 7 days; n=17) was similar to that of BIAXIN Tablets (500 mg twice daily for 7 days; n=24).

Following oral administration of multiple doses of 500 mg BIAXIN tablets twice daily, steady-state peak plasma concentrations of clarithromycin ranged from 1.4 mcg/mL to 4.1 mcg/mL and Cmax values ranged from 2.3 mcg/mL to 9.3 mcg/mL. In normal volunteers, the estimated bioavailability of a 500 mg clarithromycin tablet given under fasting conditions is 60% to 70%. Food decreases the extent of and slightly delays the absorption of clarithromycin but does not alter clarithromycin pharmacokinetics in healthy young adults.

In adult patients receiving BIAXIN Filmtabs or BIAXIN Tablets, steady-state peak plasma concentrations ranging between 8 and 15 mcg/mL have been achieved within 5 to 7 days. In pediatric patients receiving BIAXIN suspension, steady-state peak plasma concentrations ranging between 4 and 11 mcg/mL have been achieved within 5 to 14 days.

Clarithromycin and its 14-OH metabolite distribute readily into tissues. In normal volunteers, following a single oral dose of 500 mg clarithromycin as tablets, the apparent volume of distribution (V/F) is approximately 31 L/kg.

In normal adult volunteers receiving 750 mg clarithromycin as extended-release tablets (containing 47% Clarithromycin base), the mean peak serum concentration was 2.6 ± 0.4 mcg/mL and mean AUC0-12hr was 22.2 ± 4.6 mcg·hr/mL, which represents approximately 54% and 20%, respectively, of the values for clarithromycin 250 mg Tablets administered every 8 hours to normal adult volunteers.

Clarithromycin is eliminated primarily by hepatic metabolism with a mean plasma elimination half-life of 3 to 4 hours following administration of single or multiple doses. The mean serum clearance of clarithromycin ranges between 10 and 11 mL/min/kg following oral administration in healthy adult volunteers. In normal adult volunteers receiving 750 mg clarithromycin as extended-release tablets (containing 47% Clarithromycin base), the mean peak serum concentration was 2.6 ± 0.

Side Effects

The most common side effects that occurred in adult patients receiving BIAXIN Filmtabs or BIAXIN Tablets were taste disturbance (15%), nausea (9%), abdominal pain (7%), vomiting (7%), diarrhea (6%), and skin rash (5%). The most common side effect that occurred in pediatric patients receiving BIAXIN suspension was diarrhea (14%).

As well as its needed effects, clarithromycin may cause unwanted side effects that require medical attention.

Severity: Major

If any of the following side effects occur while taking clarithromycin, check with your doctor immediately:

More common:

  • Abdominal or stomach pain (continuing)
  • agitation or nervousness
  • black, tarry stools

bleeding gums or nosebleeds bloating or swelling of the face, arms, hands, lower legs, or feet blood in urine burning feeling in chest or stomach burning sensation on skin chest pain chills clay-colored stools cloudy urine confusion dizziness fast heartbeat fever general body discomfort headache itching joint pain loss of appetite lightheadedness muscle aches and pains nausea nightmares noisy breathing painful urination pale skin pinpoint red spots on skin purple patches under skin quick to react or overreact emotionally red skin lesions, often with a purple center red, irritated eyes runny nose seizures severe constipation severe diarrhea shaking skin rash sores, ulcers, or white spots on lips or in mouth sore throat sweating tightness in the chest trembling unusual bleeding or bruising unusual tiredness or weakness vision changes vomiting

Dosage and Administration

Adults  The recommended dose of BIAXIN is 250 mg to 1000 mg twice daily. Doses of up to 2000 mg/day may be used for the treatment of Pharyngitis/Tonsillitis in adults (see INDICATIONS AND USAGE). Dosages above 1000 mg/day should be administered in divided doses. The total duration of therapy should not exceed 14 days (see WARNINGS).


In humans, the oral LD50 of clarithromycin is greater than 4 g/kg in adults. Symptoms following overdosage are similar to those seen with other macrolides. They include nausea, vomiting, gastrointestinal disturbances, and dizziness. In severe cases diarrhoea, hypotension, seizures, tachycardia and arrhythmias may occur. ECG changes including QT prolongation may also be seen. There is no specific antidote for an overdose of clarithromycin; therefore treatment should be symptomatic and supportive.


Store at 25°C (77°F); excursions permitted to 15-30 °C (59-86 °F) . See USP Controlled Room Temperature. Protect from light and moisture. Dispense in a tight container.