Common side effects of clarithromycin include diarrhea, nausea or vomiting, stomach pain, heartburn, gas, changes in taste, and headaches. Clarithromycin can also cause you to feel dizzy, confused, or disoriented, so you should avoid driving or operating heavy machinery until you know what kind of impact it has on you.
This is not a complete list of adverse effects – though these are among the most common. Seek medical attention right away if you experience any of the following symptoms while taking clarithromycin:
- chest pain, shortness of breath, trouble breathing, pain or weakness in one side of your body, or slurred speech
- severe diarrhea with watery or bloody stools (up to 2 months after your treatment)
- rash
- hives
- itching
- swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
- difficulty breathing or swallowing
- hoarseness
- peeling or blistering skin
- fever
- yellowing of the skin or eyes
- extreme tiredness
- unusual bleeding or bruising
- lack of energy
- loss of appetite
- pain in the upper right part of the stomach
- dark-colored urine
- flu-like symptoms
- fast, pounding, or irregular heartbeat
- muscle weakness such as difficulty chewing, talking or performing daily activities
- double vision
As with all prescription medication, be sure to inform the prescribing doctor about any medical conditions you have been previously diagnosed with, as well as any medication/ supplements you are currently taking before starting treatment with clarithromycin.
Clarithromycin can interact with other forms of medication and substances, causing potentially serious side effects. These medications and substances include certain anticoagulants (blood thinners), certain benzodiazepines, certain cholesterol-lowering medications, astemizole (Hismanal), cisapride (Propulsid), lomitapide (Juxtapid), lovastatin (Mevacor), pimozide (Orap), simvastatin (Zocor), terfenadine (Seldane), certain ergot medicines (eg, dihydroergotamine, ergotamine, D.H.E. 45, Ergomar, Ergostat, or Migranal), and herbal supplements like St. John’s wort. If you have kidney or liver disease, you should avoid colchicine (Colcrys) while taking clarithromycin.
In addition, let your doctor know if you are pregnant or plan on becoming pregnant before starting treatment with this medication, as clarithromycin can harm the fetus.