Clarithromycin 500mg ER Tablets

Clarithromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit of susceptible bacteria. This binding interferes with the translocation of peptides, thereby inhibiting the growth of the bacteria (bacteriostatic effect).

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek medical attention:

Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Signs of liver problems: dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes.
Chest pain or pressure, rapid heartbeat, or irregular heartbeat.
Severe dizziness or fainting.
Muscle pain or weakness.
Shortness of breath.
Weakness on one side of the body, trouble speaking or thinking, balance changes, drooping on one side of the face, or blurred vision.

Important: Antibiotic-Associated Diarrhea

Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form called Clostridioides difficile-associated diarrhea (CDAD) may occur, which can lead to life-threatening bowel problems. If you experience stomach pain, cramps, or very loose, watery, or bloody stools, contact your doctor immediately. Before treating diarrhea, consult with your doctor.

Severe Skin Reactions

This medication can cause severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions, which can be life-threatening. If you notice any of the following symptoms, seek medical help right away:
Red, swollen, blistered, or peeling skin.
Red or irritated eyes.
Sores in your mouth, throat, nose, eyes, genitals, or any areas of skin.
Fever.
Chills.
Body aches.
Shortness of breath.
Swollen glands.

Other Important Information

You may notice the tablet shell in your stool, which is normal and not a cause for concern. However, if your condition does not improve and you see the tablet shell in your stool, consult with your doctor.

Common Side Effects

Most people do not experience severe side effects, but some may occur. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Stomach pain or diarrhea.
Change in taste.
Upset stomach or vomiting.
Gas.
Headache.

Reporting Side Effects

If you have questions about side effects or want to report any, contact your doctor or call the FDA at 1-800-332-1088. You can also report side effects online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
If you have previously taken this medication and experienced liver problems.
A history of abnormal heart rhythms, including a prolonged QT interval on an electrocardiogram (ECG) or other irregular heartbeats.
Certain health conditions, such as:
+ Low magnesium levels (hypomagnesemia)
+ Low potassium levels (hypokalemia)
+ Slow heartbeat (bradycardia)
* Any medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins, as some may interact with this medication. Specifically, inform your doctor about medications used to treat:
+ High cholesterol
+ Migraines
+ Mood disorders
+ Other conditions

Please note that this is not an exhaustive list of all potential interactions. This medication can interact with numerous other drugs, which may increase the risk of severe, life-threatening, or fatal side effects.

To ensure your safety, it is crucial to discuss all your medications and health conditions with your doctor and pharmacist. They will help determine whether it is safe to take this medication with your existing treatments and health status. Never start, stop, or adjust the dosage of any medication without consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

Until you understand how this drug affects you, avoid driving and other activities that require alertness. Do not exceed the prescribed duration of treatment, as this may increase the risk of a second infection.

If you have diabetes (high blood sugar), it is crucial to closely monitor your blood sugar levels while taking this medication.

This drug may cause a type of abnormal heartbeat known as a prolonged QT interval, which can increase the risk of other potentially life-threatening abnormal heartbeats. If you have a history of heart disease, consult your doctor, as one study found that patients with heart disease who took clarithromycin had a higher risk of death one year or more after treatment. However, other studies have yielded different results.

If you have myasthenia gravis, discuss your treatment with your doctor, as this condition may worsen during treatment with this medication. If your symptoms deteriorate, contact your doctor promptly.

If you are 65 years or older, exercise caution when taking this drug, as you may be more susceptible to side effects.

This medication may harm an unborn baby if taken during pregnancy. If you become pregnant or are already pregnant while taking this drug, notify your doctor immediately.

If you are breastfeeding, consult your doctor to discuss any potential risks to your baby.

• Colchicine (in patients with renal or hepatic impairment)
• HMG-CoA Reductase Inhibitors (statins) metabolized by CYP3A4 (e.g., lovastatin, simvastatin) due to increased risk of myopathy/rhabdomyolysis
• Ergotamine, Dihydroergotamine (due to acute ergot toxicity)
• Pimozide, Cisapride, Astemizole, Terfenadine (due to QT prolongation and cardiac arrhythmias)
• Ticagrelor, Ranolazine, Lomitapide, Ivabradine

• Colchicine (in patients with normal renal/hepatic function)
• Oral Anticoagulants (e.g., warfarin, acenocoumarol) - increased INR/bleeding risk
• Antiarrhythmics (e.g., quinidine, disopyramide, dofetilide, amiodarone) - increased QT prolongation risk
• Calcium Channel Blockers (e.g., verapamil, amlodipine, diltiazem) - increased hypotensive and bradycardic effects
• CYP3A4 Substrates (e.g., midazolam, triazolam, alprazolam, sildenafil, tadalafil, vardenafil, carbamazepine, phenytoin, cyclosporine, tacrolimus, sirolimus, rifabutin, omeprazole, quetiapine, clozapine, digoxin) - increased concentrations of these drugs
• Fingolimod (increased bradycardia risk)
• Ibrutinib, Venetoclax (increased toxicity)
• Dabigatran (increased bleeding risk)
• Theophylline (increased toxicity)

• Rifampin, Rifabutin, Rifapentine (decreased clarithromycin levels)
• Efavirenz, Nevirapine (decreased clarithromycin levels)
• Fluconazole (increased clarithromycin levels)
• Zidovudine (decreased zidovudine levels)
• Ritonavir, Atazanavir, Saquinavir (increased clarithromycin levels)
• Oral Hypoglycemics/Insulin (increased risk of hypoglycemia)
• Sildenafil, Tadalafil, Vardenafil (increased exposure and adverse effects)
• Phenytoin, Carbamazepine, Valproate (increased levels of anticonvulsants)
• Corticosteroids (systemic) - increased systemic exposure

• Antacids (may delay absorption but not significantly affect bioavailability)
• Food (enhances absorption of ER formulation)

• Severe or persistent diarrhea (may indicate C. difficile-associated diarrhea)
• Signs of liver injury (e.g., dark urine, yellowing of skin/eyes, abdominal pain, nausea, vomiting)
• Signs of kidney problems (e.g., decreased urination, swelling)
• Signs of allergic reaction (e.g., rash, itching, swelling, severe dizziness, trouble breathing)
• Signs of QT prolongation (e.g., palpitations, dizziness, fainting, seizures)
• Muscle pain, tenderness, or weakness (especially if on statins)

Clarithromycin is Pregnancy Category C. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Some studies suggest a possible increased risk of miscarriage and cardiovascular malformations, but data are conflicting.

Clarithromycin is excreted into breast milk. The American Academy of Pediatrics considers it compatible with breastfeeding, but caution is advised due to potential for infant GI upset (diarrhea, vomiting), thrush, or alteration of gut flora. Monitor infant for adverse effects.

Clarithromycin extended-release tablets are not recommended for use in pediatric patients under 18 years of age due to lack of established safety and efficacy and difficulty with dose adjustment for renal impairment. Immediate-release formulations are available for pediatric use with appropriate dosing.

No overall differences in safety or effectiveness were observed between elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Dose adjustment is generally not needed based on age alone, but renal function should be assessed, as elderly patients are more likely to have decreased renal function. Increased risk of adverse cardiovascular events (e.g., QT prolongation) in elderly patients with pre-existing cardiac conditions or concomitant medications.

• Always take Clarithromycin ER with food to optimize absorption and reduce GI side effects.
• Do not crush or chew the tablets; they are designed for extended release.
• Be highly vigilant for drug-drug interactions, especially with statins (lovastatin, simvastatin), colchicine, and other CYP3A4 substrates/inhibitors, as severe adverse events can occur.
• Monitor INR closely if co-administered with warfarin.
• Advise patients to report any signs of liver injury (jaundice, dark urine) or severe, persistent diarrhea (C. difficile).
• Consider alternative antibiotics in patients with significant renal impairment, as the ER formulation is difficult to dose adjust and not recommended.
• Taste disturbance (dysgeusia) is a common and often bothersome side effect of clarithromycin.

• Azithromycin (another macrolide, different pharmacokinetic profile, fewer CYP interactions)
• Erythromycin (older macrolide, more GI side effects, more frequent dosing)
• Doxycycline (tetracycline antibiotic)
• Amoxicillin/Clavulanate (beta-lactam/beta-lactamase inhibitor)
• Levofloxacin (fluoroquinolone, consider resistance and adverse effects)
• Moxifloxacin (fluoroquinolone)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.