Klacid - Use | Dosage | Side Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Klacid is a medication that contains active ingredient called clarithromycin. Klacid belongs to the family of medicines called macrolide antibiotics. Klacid kills bacteria and therefore it is used in the treatment of the following infections:

  • Respiratory tract infections (tonsillitis, sinusitis, pneumonia, bacterial bronchitis, inflammation of the pharynx)
  • Infections caused by Helicobacter pylori in stomach or duodenal ulcers


Klacid should be avoided if:

  • If you have low levels of potassium in your blood (hypokalemia)
  • If you have diabetes and you are taking medication to treat diabetes
  • If you are taking migraine medications
  • If you have hepatic or kidney disorders
  • If you have heart disorders
  • f you are taking medications to lower your cholesterol levels, such as:
    • rosuvastatin,
    • pravastatin,
    • simvastatin,
    • lovastatin,
    • fluvastatin, and others.
  • If you are taking medicines such as:
    • pimozide (used to treat psychiatric disorders),
    • cisapride (used to treat stomach problems) and anihistamines (used to treat allergies). Concomitant use of clarithromycin with these medications may cause a dangerous heart arrhythmia.
  • If you are allergic to Klacid or other similar medications such as:
    • erythromycin,
    • azithromycin, and others.
  • If you have a fungal infection and you are taking medications to treat fungal infections such as:
    • ketoconazole,
    • itraconazole,
    • fluconazole and others.
  • If you are pregnant or breast-feeding.

Klacid should not be used concurrently with alcoholic beverages. Klacid cannot be used in children younger than 12 years.

Klacid safety in pregnang woman and breastfeeding mothers

Klacid can be used during pregnancy only if the benefit to the mother outweighs the risk to the child.

Klacid may pass into breast milk and may cause harmful effects. Breastfeeding should be avoided while on Klacid therapy.

Recommended dosage

Respiratory infections: 250 mg twice a day, for at least 7 days. It is not recommended use of Klacid longer than 14 days. In severe infections, the dose can be increased to 500 mg 2 times a day for 7-14 days.

Gastric ulcer infections (H. pylori): 500 mg every eight hours, for not less than two weeks.

Klacid may be taken regardless of food, because food has no impact on Klacid effectiveness.

Use with other medications (Interactions)

Besides the aforementioned medicines, Klacid cannot be used together with following drugs:

  • Medications used to treat thrombosis, a so-called anti-coagulants, such as:
    • warfarin (Farin),
    • acenocoumarol (Sinter, Sinkum 4),
    • nadroparin (Fraxiparin) and others. Simultaneously use of Klacid with these drugs, may lead to bleeding.
  • Medications used for epilepsy treatment, such as:
    • carbamazepine,
    • valproic acid and phenytoin.
  • Medications used to treat cardiovascular disorders, such as:
    • verapamil,
    • digoxin,
    • disopyramide, and others.
  • Medicines used to reduce inflammation processes, so-called corticosteroids, such as:
    • dexamethasone,
    • fluticasone,
    • methylprednisolone, and others.
  • Theophylline, used to treat asthma
  • HIV medications, such as:
    • ritonavir,
    • saquinavir,
    • efavirenz, and others.
  • Medications used to treat erectile dysfunction.
  • Tranquilizers such as:
    • alprazolam,
    • midazolam,
    • triazolam, and others.

Tell your doctor about all medicines and herbal products you are taking.

Side effects

Possible side effects of Klacid include: allergy (skin rash, itching of the skin, swelling of the tongue, swelling of the face, difficulty breathing, anaphylactic shock), liver damage, dark urine, loss of appetite, muscle aches and joint pain, ringing in the ears, hearing impairment, nausea, abdominal pain, vomiting, diarrhea, increased sweating, heart rhythm disorders, chest pain, nervousness, mood swings, dizziness and dry mouth.

If you experience any of these side effects, contact your doctor.

Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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