Vaginal discharge is fluid secreted from tiny glands in the vagina and cervix. This fluid leaks from the vagina each day to remove old cells and debris, keeping the vagina and reproductive tract clean and healthy.
The amount of vaginal discharge can vary significantly from person to person. The color, consistency, and amount can also change from day to day, depending on where a person is in their menstrual cycle.
It is common to wonder whether the color or consistency of vaginal discharge is normal or needs to be checked out especially when you are taking certain medications.
What is metronidazole?
Metronidazole, sold under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. Metronidazole immediate-release oral tablets are used to treat many infections caused by bacteria or parasites. These include infections that occur in the gastrointestinal tract or reproductive systems such as amebiasis and trichomoniasis. Metronidazole extended-release oral tablets are used to treat vaginal infections in women.
Metronidazole may be used as part of combination therapy. This means you may need to take it with other medications.
The metronidazole immediate-release tablet and extended-release tablet are prescription drugs. They’re both taken by mouth. These tablets are available as the brand-name drugs Flagyl (immediate-release) and Flagyl ER (extended-release). Metronidazole vaginal is used to treat women with vaginal infections (eg, bacterial vaginosis).
Immediate-release drugs are released into the body right away. Extended-release drugs are released into the body slowly over time.
Both the immediate-release and extended-release tablets are available as generic drugs. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in all strengths or forms as the brand-name drug.
How it works
Metronidazole belongs to a class of drugs called nitroimidazole antimicrobials. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.
Metronidazole starts to work 1 to 2 hours after you take it, because it is quickly absorbed, and it reaches its maximum concentration after 20 minutes to 3 hours. But it may take a couple of days before you start to feel better or notice an improvement in your symptoms.
Antimicrobials are drugs used to treat infections. Nitroimidazole antimicrobials treat infections caused by bacteria and other organisms called protozoa. Metronidazole tablets work by killing the bacteria or other organisms that are causing the infection. This relieves the infection.
How should metronidazole be used?
Metronidazole comes as a tablet, an extended-release tablet, and as a capsule to take by mouth. Metronidazole capsules and tablets are usually taken as a one-time dose (or divided into two doses on 1 day) or two to four times daily for up to 10 days or longer. Metronidazole extended-release tablets are usually taken once daily at least 1 hour before or 2 hours after a meal for 7 days.
The dosage of metronidazole (vaginal) is One 500 milligram (mg) tablet, inserted high into the vagina, once a day in the evening for 10 or 20 days.
Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take metronidazole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the extended-release tablets whole; do not split, chew, or crush them.
Continue to take this medication even if you feel well. Do not stop taking it without talking to your doctor. If you stop taking this medication too soon or skip doses, your infection may not be completely treated and the bacteria may become resistant to antibiotics.
Why am I having brown discharge after taking metronidazole?
Having a brown discharge with or without an odor after taking or using metronidazole is quite common and it is not something you should worry about except when accompanied by bleeding.
The brown thick discharge after taking metronidazole will usually go away after you complete the full course of metronidazole treatment.
However, in some cases, brown discharge can be old blood that’s taking extra time to leave the uterus. This is especially true if you see it at the beginning or end of your menstrual period. Brown discharge at other points in your cycle may still be normal — but be sure to take note of any other symptoms you experience.
What side effects can metronidazole cause?
Metronidazole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
• vomiting
• nausea
• diarrhea
• constipation
• upset stomach
• stomach cramps
• loss of appetite
• headache
• dry mouth
• sharp, unpleasant metallic taste
• furry tongue; mouth or tongue irritation
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
• numbness, pain, burning, or tingling in your hands or feet
• seizures
• rash
• itching
• hives
• peeling or blistering skin
• flushing
• stuffy nose, fever, sore throat, or other signs of infection
• joint pain
• dizziness
• difficulty speaking
• problems with coordination
• confusion
• agitation
Metronidazole may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
