What Flagyl ER Is
To make it clear, the given brand name is not in use in the U.S. anymore, so check possible generic names that are rather numerous. The active substance is metronidazole, an antibiotic belonging to the class of nitroimidazoles.
The drug is used for treating anaerobic infections, including serious, complicated and chronic ones, in different organs and systems of the body (the intestinal tract, the lower respiratory system, the genitourinary system, bones, liver, blood, or the central nervous system). Metronidazole is also effective against parasite-related infections. In addition, it can be applied in surgery prophylaxis, particularly, in abdominal and gynecological interventions.
Metronidazole has proved to be carcinogenic in mice and rats, therefore, it should only be used when the positive effect of the treatment outweighs possible risks.
Recommendations for Use, Dosage and Overdose
Metronidazole can be administered orally or intravenously. For oral administration, it comes in the form of tablets (also extended release), capsules, or suspension. Alternatively, there exist injectable solutions as well as powder for injections.
As any other antibiotic, metronidazole must not be taken without doctor’s prescription! Please, avoid the unnecessary use of this drug. It should only be prescribed by a professional! Follow your prescriptions as well as the instructions on the label. Do not change the dose, dosing intervals or treatment length unless ordered by your doctor. Do not share the medication with anybody else even in case they have the same symptoms as you do. Please, keep in mind that metronidazole has been prescribed to you for your current condition only and must not be used for any other treatment.
The dosage depends on the patient’s age and weight as well as type and severity of the disease, but it should not exceed 4 g per day in adults and 2.25 g per day in children. The length of the regimen may vary from 5 to 14 days considering the same factors, most commonly 7-10. In some cases, a single dose may be taken once.
Metronidazole may also be applied in treating Trichomoniasis vaginalis infections which require simultaneous treatment of the patient’s sexual partners, even if they are asymptomatic.
The treatment of the most serious infections, especially anaerobic ones, is intravenous. The dosage, interval, and duration need to be individualized with a consideration of the patient’s age, weight, clinical condition, and response as well as supporting therapy. The drug is purely administered via slow drip infusion. The primary solution, if any, needs to be stopped during infusion of metronidazole. Infusions should not be done with aluminum-containing equipment as this element may come in contact with the drug forming precipitates.
Considering disease severity and patient response to intravenous therapy, it may be needed to switch to oral administration of metronidazole. Oral therapy mostly presupposes the administration of immediate-release tablets/capsules, unless otherwise indicated. In case of taking extended-release ones, those are not split, crushed or chewed. For better absorption, it is not advised to mix metronidazole with food, so it should be taken not less than 1 hour before or 2 hours after meals. However, it may be taken with food if the doctor tells you to do so.
Similarly to all antibiotics, metronidazole needs to be taken for a full prescribed period of time, unless it is administered once only. It is essential not to miss doses or stop the therapy ahead of time, even if the symptoms improve. If you do, you may get re-infected, and the infection has a chance for resistance to antibiotics. An overdosed patient experiences convulsions and peripheral neuropathies (malfunctions of nerves outside the brain and the spinal cord). This requires immediate medical attention.
Please, keep in mind that antibiotics, including metronidazole, has no effect for viral infections like flu or common cold. The medication should be stored at room temperature, in dry ventilated conditions away from direct sunlight.
Precautions and Contraindications
Inform your physician if you have an allergy to metronidazole (or any other allergies).
The drug is not compatible with alcohol. Avoid alcoholic beverages throughout the regimen and at least three days after. More products to eliminate are those containing propylene glycol, such as frostings, salad dressings, or flavored teas. The above-mentioned chemicals interact with metronidazole causing unwanted symptoms, namely flushing, headaches, and indigestion.
There are some groups of people metronidazole may not suitable for. Those are in particular people with nerve disorders (especially seizures), blood disorders, Cockayne, and Crohn’s disease. People with heart, liver or kidney problems as well as diabetes, also children and the elderly ought to use this medication with caution due to the increased risk of side effects.
Although well-controlled studies of metronidazole in pregnant women are insufficient, it has been assumed teratogenic; specifically, some studies revealed a probably higher risk of cleft lip. This has not been confirmed, though. However, the drug does penetrate the placental barrier and is consequently able to interfere with organogenesis in the fetus, and its influence is not known. It is also found in breast milk, so it is preferable to discontinue breastfeeding temporarily while on metronidazole.
Interactions with Other Drugs and Substances
Metronidazole is known to interact with over three hundred other drugs, therefore, the following list contains some of the most frequent interactions only: aspirin, metformin, magnesium sulfate, levofloxacin, prednisone, diazepam, lisinopril, and furosemide. Tell your physician about whatever medication you are currently taking or used to take relatively short time ago. For the same reason, any other prescriptions to patients who are taking metronidazole should be made with caution. Special focus should be put on blood thinners, antacids or laxative medicines, mineral supplements containing zinc, iron, calcium, or magnesium, tretinoin and isotretinoin, as well as any other antibiotics. Keep in mind the list is not complete, so please inform your physician on whatever you are taking.
There are also disease interactions, meaning that there are diseases associated with the administration of metronidazole, especially prolonged therapy. Those are:
- Colitis (be cautious about possible alteration of the normal colon flora);
- Blood dyscrasias;
- Neurologic toxicity;
- Alcoholism (be cautious about possible inhibition of alcohol dehydrogenase);
- Liver disease (be cautious about extensive liver metabolism).
Metronidazole as well as its metabolites may be partly removed by hemodialysis. Therefore, patients who undergo this procedure should either follow the schedule that presupposes administrations after dialysis or be given supplemental doses.
Possible unwanted reactions of metronidazole are very diverse. They are not equally frequent, and not all of them may occur, but if some do, medical attention is needed.
If you are taking metronidazole, tell your doctor right away about whichever of the following:
- Problems seeing: blurred or decreased vision, blindness, eye pain, visual hallucinations;
- Problems hearing: ear congestion, auditory hallucinations;
- Problems speaking: slurred speech, changes in speech patterns;
- Problems breathing;
- Skin and mucus membranes reactions: redness or red spots, hives, itching, yellowing, ulcers or white spots inside the mouth or on the lips, unusual and easy bruising or bleeding;
- Intestinal symptoms: loss of appetite, nausea, vomiting, bloating, dark stools, constipation, abdominal pains (sometimes radiating to the back);
- Genitourinary troubles: vaginal dryness or irritation, painful and/or unusually frequent urination, dark or bloody urine;
- Symptoms close to those of a cold: nose congestion, runny nose, cough, fever;
- Any unusual muscle pains or problems with coordination;
- Any spontaneous mood changes such as anxiety, irritation, or depression.
Keep in Mind
Provide your physician with adequate information on all conditions you have or used to have, the medicine you are taking or took some time ago, allergies (if known), pregnancy (if known), or breastfeeding. Follow the instructions provided by your doctor and remember that metronidazole, as all antibiotics, must not be self-prescribed. Keep the drug beyond children’s reach. If you have any bad side effects, inform the doctor immediately.