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Generic name: secnidazole systemic

Brand names: Solosec

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]


Mechanism of Action

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.

Dosage and Administration

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: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Adverse Reactions

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

  • Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
  • Patient may experience nausea, vomiting, headache, diarrhea, abdominal pain, or change in taste. Have patient report immediately to prescriber vaginal discharge or vaginal itching (HCAHPS).
  • Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Source: Wolters Kluwer Health. Last updated July 17, 2018.