Clarithromycin

About Clarithromycin

Clarithromycin is a macrolide antibiotic. Tablets and suspension are labeled for flare-ups of chronic bronchitis, sinus infections, community-acquired pneumonia, strep throat when first-line treatment cannot be used, uncomplicated skin infections and, in children, middle ear infections; for treating Mycobacterium avium complex (MAC) and preventing it in advanced HIV infection; and, with amoxicillin and lansoprazole or omeprazole, or with omeprazole alone, for clearing H. pylori in adults with duodenal ulcer disease. Adults usually take 250 to 500 mg every 12 hours for 7 to 14 days, and children 15 mg per kg a day in two doses for 10 days; use under 6 months of age is not established. Extended-release tablets are for adults with bronchitis flare-ups, sinus infections or pneumonia: two 500 mg tablets once a day with food. The dose is halved when kidney function is severely reduced.

There is no boxed warning. Clarithromycin must not be taken by anyone allergic to a macrolide such as erythromycin, or who had jaundice or liver problems from it before; with cisapride, pimozide, lomitapide, lovastatin, simvastatin, ergotamine, dihydroergotamine or lurasidone; or with colchicine by people with kidney or liver impairment. It can prolong the QT interval, and torsades de pointes, a dangerous heart rhythm, has been reported, so it is avoided with a known long QT interval, uncorrected low potassium or magnesium, a markedly slow heart rate, or class IA or III antiarrhythmics; older adults may be more susceptible. Other warnings cover liver injury, severe allergic and skin reactions such as anaphylaxis, Stevens-Johnson syndrome and DRESS, C. difficile diarrhea and worsening myasthenia gravis. It is not recommended in pregnancy unless no alternative is appropriate. Abdominal pain, diarrhea, nausea, vomiting and a changed sense of taste are the most common side effects.

Clarithromycin inhibits CYP3A, the liver enzyme that clears many drugs. With it, atorvastatin is held to 20 mg a day and pravastatin to 40 mg, colchicine doses are lowered, some calcium channel blockers have caused low blood pressure and, mostly in people 65 and older, kidney injury, diabetes medicines and insulin can drop blood sugar too low, and warfarin calls for frequent INR checks. In one study of people with coronary artery disease, which is not an approved use, deaths from any cause rose one year or more after a two-week course ended; the cause is not established, and the label asks prescribers to weigh this risk against the benefit. Once mixed with water, the suspension is kept at 59°F to 86°F (15°C to 30°C), not refrigerated, and used within 14 days.

Taking Clarithromycin

How to take it

Regular tablets and the suspension are taken every 8 to 12 hours, with or without food; extended-release tablets once a day with food, swallowed whole and never split, chewed or crushed. Shake the suspension well before each dose. Finish the full course even if you feel better.

If you miss a dose

Take it as soon as you remember, unless it is almost time for the next dose; then skip the missed dose and carry on as usual. Do not take a double dose.

Storage

Tablets at room temperature, away from light, excess heat and moisture, out of reach of children. Keep the mixed suspension at 59°F to 86°F (15°C to 30°C), not in the refrigerator, and throw away any left after 14 days.

Interactions to know about

Never combine it with lovastatin, simvastatin, pimozide, cisapride, ergotamine, dihydroergotamine, lomitapide or lurasidone. Atorvastatin, pravastatin, colchicine, warfarin, diabetes medicines, calcium channel blockers and sedatives such as triazolam may need dose changes or monitoring, and sildenafil, tadalafil and vardenafil are not recommended. Rifampin, rifabutin and efavirenz lower its levels.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Clarithromycin differs from pharmacy to pharmacy

Immediate-release clarithromycin tablets are an old generic that costs pharmacies little, so for a one- or two-week course the dispensing fee is a large part of the quote. Extended-release tablets and the suspension are dispensed less often, so a pharmacy may need to order them; the two kinds of tablet are different products, and a pharmacy fills only the form written.

The suspension comes in two strengths and two bottle sizes, so the quote depends on how many bottles a child’s weight-based course needs. For H. pylori, clarithromycin is one of two or three medicines, each quoted separately.

Ways to pay less for Clarithromycin without insurance

• Compare quotes from more than one pharmacy; generic tablets are priced mainly on the fee and markup.
• If extended-release tablets are quoted high, ask the prescriber whether regular tablets taken every 12 hours would suit you.
• For a child, ask which strength and bottle size cover the full course, and confirm the dose in mL.
• For H. pylori treatment, ask one pharmacy to quote the whole regimen together.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Clarithromycin

1. 1.Does it interact with my statin, colchicine, blood thinner or diabetes medicine?
2. 2.Is my prescription for the regular or the extended-release tablet?
3. 3.How do I measure my child’s dose, and when do I throw away what is left?
4. 4.Which heart rhythm or liver symptoms mean I should call right away?

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