Azithromycin Side Effects; How Long Do They Last? And More

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Anyone with a bacterial infection, whether it’s in the respiratory system or reproductive organs, has had experience taking antibiotics. One of the commonly prescribed antibiotics for several types of infectious diseases is Azithromycin.

Due to its long half-life and high tissue penetration abilities, Azithromycin is an ideal treatment for various conditions, including pneumonia, sinus infection, bronchitis, and ear and lung infections. However, like all medications and antibiotics, taking Azithromycin is not without its risks. “Azithromycin side effects how long do they last?” is a common query. This article highlights Azithromycin’s side effects and how long they last.

Regardless of which antibiotic is used for treatment, there is always a small risk of adverse side effects; Azithromycin is no different. However, these common side effects generally do not cause significant harm but only cause discomfort in most cases. As such, when it comes to questions like “azithromycin side effects how long do they last” it often comes up as people try to make the most out of the situation.

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Is Azithromycin Dangerous?

When taken as per doctors’ prescribed dosage and treatment duration, Azithromycin is not any more dangerous than other antibiotics. However, if taken outside of such prescriptions, then it can potentially harm your health.

Aside from common, relatively harmless side effects, Azithromycin is also associated with more severe health risks. One of the most significant risks of using Azithromycin is the higher likelihood of cardiac-related mortality.

A study published in JAMA Network Open in 2020 found that outpatient use of Azithromycin may lead to increased cardiovascular death compared to amoxicillin. This does not include the risks of sudden cardiac death.

The researchers noted that the increased risk is only found within five days of exposure. Data no longer shows increased risks from 6 to 10 days after taking the antibiotic. The study did note that the total number of deaths only shows a link to increased risk, rather than concretely establishing Azithromycin as the cause of the deaths.

A similar study in 2012 raised safety concerns about Azithromycin as well. In addition, the older study reported the possible link between Azithromycin and sudden cardiac death.

However, the researchers involved in the 2020 study noted that the overall benefits of Azithromycin still outweigh its potential dangers or risks. Experts not involved in the study indicated that individuals diagnosed with a disease wherein Azithromycin is the correct treatment can rest assured and safely take the antibiotic.

Other medical experts have also noted that individuals without a history of heart-related illnesses have nothing to worry about. As per the studies and reviews, only those with pre-existing heart conditions see an increase in potentially fatal heart-related azithromycin side effects. In addition, no evidence has been found that links the antibiotic with higher mortality without any heart disease.

How Long Will Azithromycin Stay In Your System?

Unlike other alternative antibiotics like amoxicillin and ciprofloxacin, Azithromycin lasts for a long time in your body. It generally stays in your system for up to 15 days or around two weeks after completing the entire course of treatment.

Azithromycin has an extended elimination half-life of 68 hours or around two to four days. This refers to the time the antibiotic’s active substance takes to be reduced by half. This contributes to its long-lasting effect.

Please take note, though, that the amount of time it takes for Azithromycin to exit your system depends on several factors. These include:

  • Prescribed dosage or treatment course
  • Usage frequency
  • Metabolic rate
  • Body mass
  • Age
  • Genetics
  • Kidney and liver functions or any related underlying medical conditions
  • Overall health

Azithromycin Warnings

Azithromycin has specific warnings regarding contraindications. In addition, it has several potential interactions with other drugs and specific health conditions.

General Precautions

As with any other antibiotic or medication, inform your physician or pharmacist about any allergies, particularly past allergic reactions to other macrolide-class medications. These include clarithromycin and erythromycin.

It is also best to double-check with your doctor regarding potential azithromycin interactions with other drugs you may be taking. Always inform them about prescription and nonprescription medications, especially blood thinners like warfarin. It is also better to tell them about any vitamins, herbal products, and other supplements you may take.

If you have experienced or currently have liver problems or jaundice (yellowing of the eyes or skin), especially if it’s due to Azithromycin or other macrolides, you may need to ask for alternative antibiotics. Make sure to inform your doctor of such cases.

Always take Azithromycin as directed by your doctor. Never go beyond the prescribed treatment dose and duration. It is also ill-advised to stop the treatment before the end of the prescription. If you are feeling better even before the treatment course ends, it is better to consult your doctor first.

Make sure to discard any unused oral suspension azithromycin once the total dosing or treatment course is completed or 12 hours following its preparation. It is also advised to discard any leftover Azithromycin oral suspension after ten days.

Azithromycin and Pregnancy

The FDA classifies Azithromycin as a pregnancy category B drug. This means there is no proven risk in humans, though there have not been enough well-controlled tests conducted on pregnant women to warrant a conclusive result. In addition, animal tests have so far shown little to no risk.

While there have not been any identified risks for major fetal defects, miscarriage, or other adverse birth outcomes, women are still advised to be cautious when taking antibiotics during pregnancy.

For breastfeeding women, taking Azithromycin may cause side effects for the breastfed baby. These can include vomiting, rash, and Diarrhea. Therefore, it is best to consult a healthcare specialist, particularly an OB-GYN, before taking Azithromycin while breastfeeding.

When and What Not To Take With Azithromycin

You may take Azithromycin with or without food. However, some people have noted that the drug can be better tolerated if taken after a meal.

It is recommended not to take antacids containing aluminum or magnesium at least two hours before or after taking Azithromycin. Doing so can lessen the overall effectiveness of the antibiotic.

Doctors advise against Azithromycin for prophylaxis of bronchiolitis obliterans syndrome (BOS). Patients are also advised to immediately discontinue azithromycin treatment if they develop cholestatic jaundice, abnormal liver function, hepatic necrosis, or hepatic failure. Reports of these conditions have resulted in fatalities following continued treatment of Azithromycin.

Patients diagnosed with myasthenia gravis, a disease that weakens the muscles, are advised not to take Azithromycin as it may worsen their condition.

When taking azithromycin tablets and oral liquid suspension, the usual treatment duration is once daily for up to five days. Avoid taking the medication at different times each day, as this may cause you to forget and miss some doses.

Azithromycin Side Effects

Similar to other antibiotics, Azithromycin carries a particular risk of side effects. The medication’s side effects range from common ones that subside within a short period to rare, serious complications that warrant immediate medical attention.

More Common Side Effects of Azithromycin

Azithromycin shares some common side effects with other antibiotics, such as:

  • Diarrhea or loose stools
  • Nausea
  • Vomiting
  • Stomach or abdominal pains
  • Headache
  • Tightness in the chest
  • Swelling

Other side effects that are not as prevalent but are not considered severe include:

  • Itching, reddening, or blistering of the skin
  • Dry, cracked, or scaly skin
  • Hives
  • Fever
  • Chills
  • Bloody or cloudy urine
  • Body aches or pain
  • Drowsiness
  • Fainting
  • Fast, irregular heartbeat
  • Indigestion
  • Difficulty breathing or swallowing
  • Lack of energy
  • Loss of appetite

Serious Side Effects of Azithromycin

Azithromycin can cause severe adverse effects that can potentially be fatal or affect patients’ overall health and long-term quality of life. These include:

Liver problems. Symptoms of this side effect include general weakness, appetite loss, dark urine, abdomen pain, and jaundice or yellowing of the eyes and skin.

Severe allergic reactions. The usual symptoms include difficulty breathing, swelling of the face, and hives or reddening of the skin, Diarrhea due to Clostridium difficile bacteria. Common symptoms include reduced appetite, fever, nausea, and abdominal pain.

Infantile hypertrophic pyloric stenosis. This refers to a narrowing or blockage in part of an infant’s digestive system. Its symptoms include irritability during feeding, vomiting after eating, and difficulty or inability to gain weight.

QT prolongation. This causes rapid or irregular heartbeat. Symptoms include fainting, gasping while asleep, and a fluttering feeling in the chest.

Azithromycin Side Effects on the Heart

The FDA has long since warned the public about Azithromycin’s potential cardiovascular death risks. In 2013, the agency issued an official warning that Azithromycin, commonly sold under Zmax and Zithromax, may cause QT prolongation or irregular heart activity as a side effect. This can potentially result in a fatal heart rhythm.

QT prolongation or long QT syndrome (LQTS) is a heart-signaling disorder. It can cause arrhythmias or chaotic heartbeats. The resulting heart rate from the syndrome can lead to sudden fainting, seizures, and higher sudden mortality risk.

Taking Azithromycin and other macrolide-class antibiotics like clarithromycin and erythromycin can increase the heartbeat to 200 times per minute. However, the heart’s pumping capabilities are significantly decreased at that speed. As a result, it fails to pull in and pump out enough blood that the body needs.

As a result, the individual’s blood pressure drops. This is also the reason behind the sudden fainting and seizures. In worst-case scenarios, the difficulties in pumping may cause the heart to stop pumping blood altogether. Without timely treatment, such as a charge with a defibrillator, this results in sudden cardiac death.

A 2012 study found that cardiac deaths increased the risk of cardiac deaths within five days of azithromycin intake by almost threefold. This is in comparison to amoxicillin, another widely prescribed antibiotic.

A retrospective cohort study in 2020 once again put the spotlight on this associated risk. The cohort study looked into over 7.8 million antibiotic exposures, including 1.7 million or 22.2% of azithromycin exposures.

Like the 2012 findings, the researchers found that patients who took Azithromycin had significantly higher cardiovascular mortality within five days compared to amoxicillin. However, they excluded sudden cardiac death from this. The findings also noted that Azithromycin is linked to a higher risk of all-cause death within the same period.

Furthermore, the researchers noted that most patients who experienced cardiac arrhythmias related to Azithromycin and other macrolides have underlying heart conditions that further raise their risks. These existing conditions included:

  • Baseline QT prolongation
  • Cardiomyopathy
  • Congestive heart failure
  • Bradycardia, or prolonged heart rate
  • Atrial fibrillation, or irregular and likely fast heart rate
  • Myocardial ischemia, or reduced blood flow

Due to concern over Azithromycin’s association with QT prolongation, which refers to prolonged intervals in heart rhythm, the FDA recommended using the antibiotic on patients with known risk factors for heartbeat irregularities or ventricular arrhythmia.

If you or a loved one took Azithromycin and experienced any of the following warning signs, call your physician or visit medical emergency services right away:

  • Lightheadedness
  • Blurred vision
  • Heart palpitations
  • General weakness
  • Fainting due to excitement, anger, or physical activity

Undergoing an electrocardiogram (ECG) test will confirm whether you or your loved one developed acquired LQTS.

Azithromycin Side Effects How Long Do They Last in the body?

People frequently ask one question: “azithromycin side effects how long do they last?” Since common side effects do not pose much danger to individuals taking Azithromycin, knowing how long the adverse effects last helps minimize discomfort.

The more common or milder side effects of taking the drug generally subside after a few days or weeks. If these side effects take much longer to go away or escalate in severity, make sure to contact a medical professional.

Fevers as a side effect generally last 24 to 48 hours after medicine intake. If it lasts beyond that, make sure to consult a doctor.

Diarrhea side effects may occur for up to two months after finishing an azithromycin treatment course. The longer time the antibiotic can remain in our system is responsible for this. Taking diarrhea medication during this time is not advisable as it may lead to the condition worsening or lasting longer.

Some of the severe side effects of Azithromycin may last for weeks or months, such as allergic reactions that manifest as Stevens-Johnson syndrome. However, other severe side effects can be permanent, like liver problems and QT prolongation.

Azithromycin Interactions With Other Medications

Azithromycin has several known drug interactions. Among the list of medications to avoid taking with this antibiotic are:

  • Amoxicillin/clavulanate (Advair Diskus)
  • Fluticasone/salmeterol (Augmentin)
  • Albuterol (ProAir HFA, Ventolin HFA)
  • Budesonide / formoterol (Symbicort)
  • Warfarin
  • Nelfinavir
  • Bepridil
  • Ergotamine
  • Ergonovine
  • Terfenadine
  • Ziprasidone
  • Methylergonovine
  • Pimozide
  • Levoketoconazole
  • Dihydroergotamine

Some medications are generally not recommended for Azithromycin but may be safely taken in lower doses. These include:

  • Amoxapine
  • Asenapine
  • Buprenorphine
  • Ciprofloxacin
  • Clarithromycin
  • Clofazimine
  • Clozapine
  • Disopyramide
  • Digoxin
  • Desipramine
  • Erythromycin
  • Fluconazole
  • Hydroxychloroquine
  • Iloperidone
  • Levofloxacin
  • Methadone
  • Morphine
  • Moxifloxacin
  • Simvastatin
  • Tacrolimus

Interactions That Increase Your Risk of Side Effects

Taking Azithromycin with anticoagulants or blood thinners increases patients’ risk of bleeding. Warfarin, in particular, can significantly raise the risk of adverse effects. Similarly, taking nelfinavir while undergoing an azithromycin treatment course increases the risk of liver damage and ear infection.

Azithromycin can increase the risk of fatal arrhythmias for people with QT prolongation or abnormal heart rhythm and uncontrolled or decompensated heart failure for conditions or health-related interactions.

Azithromycin may also work differently for patients with the following existing medical conditions and who are taking prescribed medications or treatments for them:

  • Diarrhea
  • Cystic fibrosis
  • Weak immune system or physical conditions
  • Myasthenia gravis
  • Kidney and liver disease
  • Hypokalemia, or low potassium levels in the blood
  • Hypomagnesemia, or low magnesium levels in the blood
  • Bacteremia

Allergic Reactions to Azithromycin

Some individuals experience hypersensitivity or allergic reactions to Azithromycin. In such cases, discontinue the antibiotic and consult a doctor for an alternative treatment.

Common symptoms of antibiotic allergic reactions include:

  • Trouble breathing
  • Trouble swallowing
  • Swelling of the lips, tongue, throat, or the entire face
  • Itching, hives, and rashes

Severe, life-threatening allergic reactions to Azithromycin that have been reported include:

Anaphylaxis, wherein the blood pressure lowers quickly and drastically while the airways tighten, resulting in difficulty breathing or shock.

Angioedema, or swelling under the skin, while generally not severe, can be fatal if the swollen areas affect one’s breathing.

Stevens-Johnson syndrome is characterized by a painful, blistering rash and the dying top layer of affected skin.

Acute Generalized Exanthematous Pustulosis (AGEP), wherein the skin reddens and becomes studded with pinhead-sized sterile pustules.

Drug reaction with eosinophilia and systemic symptoms (DRESS), a severe adverse drug reaction whose symptoms include rash, fever, swollen lymph nodes or glands, and single or multiple organ involvement.

What To Do If You Miss a Dose of Azithromycin?

If you miss taking a dose, it is better to immediately take the missed azithromycin dose. However, if it is almost time to take the next dosage, it is better to skip the missed dose instead. Instead, wait until your next dose intake and continue your dosing schedule. Never double your amount to make up for a missed schedule.

When To See a Doctor

If you experience any severe side effects or allergic reactions, contact your doctor or emergency health services immediately. It is also better to consult a medical professional should common, or less serious side effects continue over a prolonged period.

Call a doctor immediately if you vomit within an hour of taking Azithromycin. Do not ignore the situation or persist with going through the prescribed treatment course without consulting a medical professional.

It is also recommended to contact your physician if your symptoms fail to improve or get even worse during the treatment duration.

Frequently Asked Questions

It generally takes about 15 days or around two weeks for Azithromycin to leave your system entirely after the last dose. However, this estimate may change depending on several factors.

These include your dosage and treatment course, metabolic rate, body mass, age, and overall health. In addition, existing liver or kidney conditions can also affect the rate at which Azithromycin exits our body.

Azithromycin has several serious side effects. These include liver problems, QT prolongation, severe allergic reactions, Diarrhea due to C. difficile bacteria, and infantile hypertrophic pyloric stenosis. Prolonged Diarrhea may also cause dehydration.

Infantile hypertrophic pyloric stenosis is the narrowing of part of a newborn infant’s digestive system, resulting in symptoms such as vomiting, irritability after feeding, and inability to gain weight. Meanwhile, QT prolongation increases the risk of cardiovascular-related deaths.

Make sure to immediately contact emergency health services or your physician in case of any severe side effects.

It is generally frowned upon to use expired antibiotics and other drugs. Expiration dates mark the date that drug manufacturers can guarantee their medications’ full potency and safety.

The U.S. Food and Drug Administration (FDA) cautioned people against expired medications due to the risk of bacterial growth and lower antibiotic potency. Sub-potent antibiotics can not only fail to treat infectious diseases but can also cause more illnesses and lead to higher antibiotic resistance. This can significantly impede future antibiotic treatments. You can check the FDA’s Azithromycin page for the latest news about the drug.

Yes, some antibiotics continue working for a while, even after the prescribed treatment course is finished. This is due to the overall life of the antibiotic in your body.

Some antibiotics like amoxicillin or ciprofloxacin stay in your system for up to another day after the last dosage. For Azithromycin, though, the drug can continue to stay in your system and work for up to 15 days after your last dose.

The content on Doctor Alexa’s blog is reviewed by Advanced practice registered nurses or pharmacist and is intended for educational purposes only. This information should not be relied upon as professional medical counsel. Be sure to always consult with your physician about the dangers and benefits of any medication, treatment or procedure.

You shouldn’t wait to see the doctor for simple health needs.