Less common side effects (<1%) include extreme irritability, hallucinations (auditory and visual), dizziness/motion sickness, and alteration in senses of smell and taste, including a metallic taste. Dry mouth, panic attacks, and nightmares have also been reported, albeit less frequently. Cardiac
In February 2018, the FDA issued a Safety Communication warning with respect to an increased risk for heart problems or death with the use of clarithromycin, and has recommended that alternative antibiotics be considered in those with heart disease.Clarithromycin can lead to a prolonged QT interval. In patients with long QT syndrome, cardiac disease, or patients taking other QT-prolonging medications, this can increase risk for life-threatening arrhythmias.In one trial, the use of short-term clarithromycin treatment was correlated with an increased incidence of deaths classified as sudden cardiac deaths in stable coronary heart disease patients not using statins. Some case reports suspect it of causing liver disease. Liver and kidney
Clarithromycin has been known to cause jaundice, cirrhosis, and kidney problems, including kidney failure. Central nervous system
Common adverse effects of clarithromycin in the central nervous system include dizziness, headaches. Rarely, it can cause ototoxicity, delirium and mania. Infection
A risk of oral candidiasis and vaginal candidiasis, due to the elimination of the yeasts natural bacterial competitors by the antibiotic, has also been noted. Pregnancy and breastfeeding
Clarithromycin should not be used in pregnant women except in situations where no alternative therapy is appropriate. Clarithromycin can cause potential hazard to the fetus hence should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
For lactating mothers it is not known whether clarithromycin is excreted in human milk. Interactions
Clarithromycin inhibits a liver enzyme, CYP3A4, involved in the metabolism of many other commonly prescribed drugs. Taking clarithromycin with other medications that are metabolized by CYP3A4 may lead to unexpected increases or decreases in drug levels. A few of the common interactions are listed below. Colchicine
Clarithromycin has been observed to have a dangerous interaction with colchicine as the result of inhibition of CYP3A4 metabolism and P-glycoprotein transport. Combining these two drugs may lead to fatal colchicine toxicity, particularly in people with chronic kidney disease. Statins
Taking clarithromycin concurrently with certain statins (a class of drugs used to reduce blood serum cholesterol levels) increases the risk of side effects, such as muscle aches and muscle break down (rhabdomyolysis). Calcium channel blockers
Concurrent therapy with calcium channel blocker may increase risk of low blood pressure, kidney failure, and death, compared to pairing calcium channel blockers with azithromycin, a drug similar to clarithromycin but without CYP3A4 inhibition. Administration of clarithromycin in combination with verapamil have been observed to cause low blood pressure, low heart rate, and lactic acidosis. Carbamazepine
Clarithromycin may double the level of carbamazepine in the body by reducing its clearance, which may lead to toxic symptoms of carbamazepine, such as double vision, loss of voluntary body movement, and nausea, as well as hyponatremia. HIV medications
Depending on the combination of medications, clarithromycin therapy could be contraindicated, require changing doses of some medications, or be acceptable without dose adjustments.