Erythromycin 500mg EC Tablets

Erythromycin inhibits bacterial protein synthesis by reversibly binding to the 50S ribosomal subunit of susceptible microorganisms. This binding prevents the translocation of peptidyl tRNA, thereby inhibiting polypeptide synthesis and bacterial growth. It is generally considered bacteriostatic, but may be bactericidal at high concentrations or against highly susceptible organisms.

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 or seek immediate medical attention:

Signs of an allergic reaction, such as:
+ Rash or hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Difficulty breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Fatigue
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Signs of a severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), such as:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Urination problems, including inability to pass urine or changes in urine output
Severe dizziness or fainting
Rapid heartbeat
Abnormal heartbeat (long QT on ECG), which can be life-threatening. This risk may be increased when taking other medications with this drug. Seek medical help immediately if you experience an irregular heartbeat.
Diarrhea, especially if it is severe, bloody, or watery. Although diarrhea is common with antibiotics, a rare but potentially deadly condition called C. diff-associated diarrhea (CDAD) may occur. Contact your doctor right away if you experience stomach pain, cramps, or severe diarrhea. Do not treat diarrhea without consulting your doctor.
Hearing loss, which may be temporary or permanent. This risk is higher if you have kidney problems or take high doses of this medication. If you experience hearing problems, contact your doctor immediately.

Other Possible Side Effects

Most people do not experience significant side effects, but some may occur. If you notice any of the following symptoms, contact your doctor or seek medical attention if they bother you or persist:

Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite

This is not an exhaustive list of possible side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or 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. Describe the allergic reaction you experienced, including the symptoms that occurred.
Certain health conditions, including:
+ Abnormal heart rhythms, such as a prolonged QTc interval on an electrocardiogram (ECG)
+ Other irregular heartbeats
+ Slow heartbeat
+ Low potassium or magnesium levels

Additionally, tell your doctor about all the medications you are taking, including:

Prescription and over-the-counter (OTC) drugs
Natural products
* Vitamins

Some medications, particularly those used to treat mood disorders, abnormal heart rhythms, or migraine headaches, should not be taken with this medication. There are many other drugs that may interact with this medication, so it is crucial to disclose all your medications to your doctor.

To ensure your safety, inform your doctor and pharmacist about all your medications and health problems. Verify that it is safe to take this medication with your existing medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.

Important Information for Patients Taking This Medication

It is crucial that you inform all of your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this drug. If you are taking this medication long-term, your doctor may recommend regular blood tests to monitor your condition.

Please note that this medication may interfere with certain laboratory tests. Be sure to notify all of your healthcare providers and laboratory personnel that you are taking this drug.

Duration of Use and Potential Risks

Do not take this medication for longer than prescribed by your doctor. Prolonged use may increase the risk of a second infection.

Dietary Considerations and Interactions

If you are following a low-sodium or sodium-free diet, consult with your doctor before taking this medication, as some products may contain sodium.

Special Precautions for Certain Medical Conditions

If you have myasthenia gravis, discuss your treatment with your doctor. Monitor your condition closely, and contact your doctor immediately if your symptoms worsen. Additionally, be aware that this medication may cause signs of myasthenia gravis in people who do not have the condition. Seek medical attention right away if you experience new or worsening muscle weakness, difficulty chewing or swallowing, breathing problems, droopy eyelids, or changes in vision, such as blurred vision or double vision.

Age-Related Considerations

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.

Pregnancy and Breastfeeding

If you are pregnant, planning to become pregnant, or breastfeeding, consult with your doctor to discuss the potential benefits and risks of this medication to you and your baby.

Special Considerations for Newborns

In rare cases, newborns taking this medication may develop a severe stomach problem. If your child vomits or becomes irritable during feeding, contact your doctor immediately.

• Astemizole
• Cisapride
• Pimozide
• Terfenadine
• Ergotamine
• Dihydroergotamine
• Colchicine (in patients with renal/hepatic impairment)
• Lomitapide
• Simvastatin
• Lovastatin

• Amiodarone
• Disopyramide
• Dofetilide
• Procainamide
• Quinidine
• Sotalol
• Warfarin
• Carbamazepine
• Theophylline
• Cyclosporine
• Tacrolimus
• Sirolimus
• Digoxin
• Alprazolam
• Midazolam
• Triazolam
• Felodipine
• Nifedipine
• Verapamil
• Diltiazem
• Rifampin
• Phenytoin
• Valproic acid
• Clarithromycin
• Azithromycin (additive QT prolongation risk)
• Fluconazole
• Itraconazole
• Ketoconazole
• Voriconazole
• Ritonavir
• Saquinavir
• Atazanavir
• Nelfinavir
• Statins (atorvastatin, rosuvastatin, fluvastatin, pravastatin - increased risk of myopathy/rhabdomyolysis)
• Quetiapine
• Ziprasidone
• Clozapine
• Fentanyl
• Alfentanil
• Sildenafil
• Tadalafil
• Vardenafil
• Tolterodine
• Solifenacin
• Eletriptan
• Zolmitriptan
• Ranolazine
• Ivabradine
• Domperidone
• Hydroxychloroquine
• Chloroquine
• Citalopram
• Escitalopram
• Ondansetron
• Tramadol
• Methadone

• Oral contraceptives (reduced efficacy)
• Corticosteroids (methylprednisolone)
• Cimetidine
• Ranitidine
• Omeprazole
• Lansoprazole
• Antacids (may reduce absorption of some erythromycin formulations)
• Zidovudine
• Didanosine
• Clindamycin
• Lincomycin (antagonistic effect)
• Sulfonylureas (increased hypoglycemia risk)
• Metoprolol
• Propranolol
• Warfarin (increased INR)
• Colchicine (increased toxicity in normal renal/hepatic function)
• Bosentan
• Eplerenone
• Fesoterodine
• Darifenacin
• Tolvaptan
• Conivaptan
• Dabigatran
• Rivaroxaban
• Apixaban
• Edoxaban

• Food (for non-EC formulations)
• Grapefruit juice (potential minor interaction)

• Diarrhea
• Nausea
• Vomiting
• Abdominal pain/cramping
• Jaundice
• Dark urine
• Fatigue
• Tinnitus
• Hearing loss
• Vertigo
• Rash
• Pruritus
• Signs of superinfection (e.g., oral thrush, vaginal yeast infection, C. difficile-associated diarrhea)
• Chest pain
• Palpitations
• Dizziness
• Fainting

Erythromycin is generally considered safe for use during pregnancy (Pregnancy Category B). It is often used as an alternative for penicillin-allergic pregnant women.

Erythromycin is excreted into breast milk in small amounts. It is generally considered compatible with breastfeeding (Lactation Risk L2 - likely compatible). Monitor breastfed infant for potential adverse effects.

Dosing is weight-based. Use with caution in neonates due to potential for infantile hypertrophic pyloric stenosis (IHPS), especially when used in the first few weeks of life. Monitor for vomiting and feeding intolerance.

No specific dose adjustment is generally needed based on age alone. However, elderly patients may be more susceptible to QT prolongation and hearing loss, especially with higher doses or pre-existing renal/hepatic impairment. Monitor closely for adverse effects and drug interactions.

• Erythromycin is a potent CYP3A4 inhibitor, leading to numerous significant drug interactions. Always review concomitant medications.
• Enteric-coated (EC) formulations are designed to reduce gastrointestinal upset and improve absorption by protecting the drug from stomach acid. Do not crush or chew EC tablets.
• While generally safe, erythromycin can cause QT prolongation and Torsades de Pointes, especially in patients with pre-existing cardiac conditions, electrolyte imbalances, or on other QT-prolonging drugs.
• Hepatotoxicity (cholestatic hepatitis) and ototoxicity (reversible hearing loss, tinnitus) are rare but serious side effects, more common with high doses or in patients with renal/hepatic impairment.
• Erythromycin has prokinetic properties and is sometimes used off-label for gastroparesis, typically at lower doses than for antibacterial effects.
• Resistance to macrolides is increasing, limiting their empirical use in some regions for certain infections.

• Azithromycin (another macrolide, longer half-life, less frequent dosing, fewer CYP interactions)
• Clarithromycin (another macrolide, fewer doses per day than erythromycin, significant CYP interactions)
• Penicillins (e.g., Amoxicillin, Penicillin V - for susceptible streptococcal infections)
• Tetracyclines (e.g., Doxycycline - for atypical pneumonia, chlamydial infections)
• Fluoroquinolones (e.g., Levofloxacin, Moxifloxacin - for respiratory tract infections, but with broader spectrum and different side effect profile)
• Clindamycin (for anaerobic infections, skin/soft tissue infections, but different spectrum and C. difficile risk)

If your symptoms or health issues persist or worsen, it is 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 it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about this 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, including the amount taken and the time it happened, to ensure you receive the best possible care.