DYSEN SUSPENSION

Indications

• Trichomoniasis
• Amebiasis
• Giardiasis
• Bacterial vaginosis

Dosage

Children: Refer to the BNF for Children for specific dosing tailored to paediatric patients.

Adults: Refer to the BNF for appropriate dosing information based on the specific infection being treated.

Mechanism of action

Secnidazole's antimicrobial and antiprotozoal effects stem from the reduction of its nitro group by bacterial or parasitic nitroreductase enzymes. This process generates radical anions and reactive intermediates that deplete thiols, damage DNA helix structure, disrupt protein synthesis, and lead to the replication inhibition and death of susceptible microorganisms.

Pharmacodynamics

Secnidazole is effective against a variety of anaerobic pathogens, including Bacteroides fragilis and Trichomonas vaginalis. It also shows activity against Entamoeba histolytica and Giardia lamblia in in vitro studies. While secnidazole may prolong the QTc interval, this effect is generally not considered clinically significant.

Pharmacokinetics

Secnidazole is well-absorbed and has a bioavailability that supports its efficacy in treating infections. It is metabolized in the liver and excreted primarily in urine. The pharmacokinetic properties facilitate its use in a variety of infectious conditions, ensuring adequate therapeutic concentrations are achieved in affected tissues.

Contra-indications

• Hypersensitivity to secnidazole or any component of the formulation
• Severe hepatic impairment
• History of seizure disorders

Adverse effects

• Nausea
• Vomiting
• Abdominal pain
• Dizziness
• Headache
• Dry mouth
• Altered taste
• Peripheral neuropathy
• Skin reactions

Interactions

• Alcohol - may cause disulfiram-like reactions
• Anticoagulants - may enhance anticoagulant effects
• Lithium - may increase lithium levels

Precautions

• Use with caution in patients with a history of neurological disorders
• Monitor for signs of peripheral neuropathy
• Caution in patients with hepatic impairment

Pregnancy

Secnidazole should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consultation with a healthcare provider is recommended.

Breast-feeding

It is not known whether secnidazole is excreted in human milk. Caution should be exercised when administering to breastfeeding women.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Tablets for oral administration

Mechanism of action

Like other 5-nitroimidazole antimicrobials, the antimicrobial and antiprotozoal activity of secnidazole is accounted for by the nitro group in the imidazole ring. Upon entering the target pathogen, the nitro group of secnidazole is reduced by bacterial or parasitic nitroreductase enzymes, producing radical anions and reactive intermediates. Radical anions and reactive intermediates cause the depletion of thiols, DNA helix damage, disruption of bacterial or parasitic protein synthesis and replication, and ultimately, cell death of susceptible isolates of Gram positive bacteria, Gram negative bacteria and _T. vaginalis_.

Pharmacodynamics

Secnidazole is a broad-spectrum nitroimidazole antimicrobial drug. It is selective against many anaerobic Gram-positive and Gram-negative bacteria and protozoa. According to _in vitro_ studies, secnidazole mediates antibacterial effects against _Bacteroides fragilis_, _Trichomonas vaginalis_, _Entamoeba histolytica_, and _Giardia lamblia_. Secnidazole may prolong the QTc interval, but not to a clinically significant extent.