Metronidazole (brand name Flagyl) is an antibiotic medicine used to kill certain bacteria that cause skin and soft tissue abscesses, sexually transmitted diseases (STDs), giardia, some vaginal and amoebic infections. Recommended Regimens. Metronidazole 500 mg orally twice a day for 7 days OR; Metronidazole gel 0.75%, one full applicator (5 g) intravaginally, once a day for 5 days Usually, a dose of 3 mg to 23 mg per pound is given to dogs, one to four times a day. The recommended dose of metronidazole for cats is 5 mg to 23 mg per pound, once or twice a day. So if you are thinking of giving this medicine to your dog, then you should first check the weight of your dog and then calculate the dose accordingly. i was told i had samonal in my colen in jan was given metronidazole 500 mg for 10 days i took them for 8 days & was beter. 3 days later it came back.i was given metronidazole 250 mg for 14 days afte … I have metronidazole 500mg tablets to be taken twice a day for 7 days because i have gum pain which only started last - Answered by a verified Doctor I am on day 7 of a 10 days of these medications for diverticulitis. I have tried to be careful of what I eat and of course what I am expelling. 2 g orally once daily single dose with erythromycin (500 mg four times/day) or erythromycin ethylsuccinate (800 mg four times/day) x 7 days Pelvic Inflammatory Disease (Off-label) 500 mg orally every 12 hours for 14 days in conjunction with ofloxacin or levofloxacin Adults—500 or 750 milligrams (mg) 3 times a day for 5 to 10 days. Children—Dose is based on body weight and must be determined by your doctor. The dose is usually 35 to 50 milligrams (mg) per kilogram (kg) of body weight per day, divided into 3 doses, for 10 days. Doctors give unbiased, trusted information on the benefits and side effects of Flagyl to treat Bacterial Vaginosis: Dr. Peralta on will 7 days of taking metronidazole clear up bv: Yes. Search Sign up free Adults and children over 10 years: 2g once a day for 3 days, or 400mg three times a day for 5 days or 500mg twice daily for 7 to 10 days. Children 7-10 years: 1g once a day for 3 days. Children 3 - 7 years 600mg-800mg once daily for 3 days.