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Medically reviewed by Last updated on Jun 18, 2020.


(sek NID a zole)

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Packet, Oral:

Solosec: 2 g (1 ea) [contains polyethylene glycol]

Brand Names: U.S.

  • Solosec

Pharmacologic Category

  • Antibiotic, Miscellaneous
  • Antiprotozoal, Nitroimidazole


After entering the bacterial cell, it is proposed that secnidazole interferes with bacterial DNA synthesis of susceptible isolates.


Vd: ~42 L


Hepatic via CYP-450; undergoes oxidation with ≤1% conversion to metabolites.


Urine (~15% unchanged)

Time to Peak

4 hours (range: 3 to 4 hours)

Half-Life Elimination

~17 hours

Protein Binding


Use: Labeled Indications

Bacterial vaginosis: Treatment of bacterial vaginosis in adult women


Hypersensitivity to secnidazole, other nitroimidazole derivatives, or any component of the formulation.

Dosing: Adult

Bacterial vaginosis: Oral: 2 g single dose

Dosing: Geriatric

Refer to adult dosing.


Administer without regard to timing of meals. Sprinkle entire contents of one packet onto applesauce, yogurt, or pudding; granules will not dissolve. Consume entire mixture within 30 minutes; do not chew or crunch granules. May consume water after administration to aid in swallowing.


Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).

Drug Interactions

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Avoid combination

Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Consider therapy modification

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

Note: Nonapproved dosing regimens are included in the reported incidences.

1% to 10%:

Central nervous system: Headache (4%)

Gastrointestinal: Nausea (4%), diarrhea (3%)

Genitourinary: Vulvovaginal candidiasis (10%)

<1%, postmarketing, and/or case reports: Abdominal pain, dysgeusia, vomiting


Concerns related to adverse effects:

• Carcinogenic: Carcinogenicity has been observed in mice and rats with nitroimidazole agents that are structurally similar to secnidazole in animal studies; it is unknown whether secnidazole is associated with carcinogenicity in humans. Avoid chronic use.

Disease-related concerns:

• Candidiasis: Vulvovaginal candidiasis may occur; antifungal treatment may be necessary if patient is symptomatic.

Pregnancy Considerations

Adverse events were not observed in animal reproduction studies. Information related to the use of secnidazole in pregnancy is limited (Camargo 2015).

Patient Education

What is this drug used for?

• It is used to treat vaginal infections.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Nausea

• Vomiting

• Headache

• Diarrhea

• Abdominal pain

• Change in taste

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Vaginal discharge

• Vaginal itching

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine’s uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.