Usage
Miconazole + Ornidazole is prescribed for mixed vaginal infections, including:
- Vaginal Candidiasis (Yeast Infection): Caused by Candida species, primarily Candida albicans.
- Vaginal Trichomoniasis: A sexually transmitted infection (STI) caused by the protozoan parasite Trichomonas vaginalis.
- Bacterial Vaginosis: Characterized by an overgrowth of anaerobic bacteria in the vagina.
Pharmacological Classification:
- Miconazole: Imidazole antifungal
- Ornidazole: Nitroimidazole antibiotic/antiprotozoal
Mechanism of Action:
Miconazole inhibits ergosterol synthesis, a critical component of fungal cell membranes, resulting in fungal cell death. Ornidazole damages bacterial and protozoal DNA, inhibiting cell division and leading to microbial death. The combined action addresses the multiple infectious agents often present in vaginitis.
Alternate Names
This combination is marketed under various brand names, including Candifem (vaginal tablets/cream), Candimic-OZ (cream), and Micotran (suppositories). Other brand names may exist regionally.
How It Works
Pharmacodynamics:
Miconazole acts locally to disrupt the fungal cell membrane by inhibiting ergosterol synthesis. Ornidazole, also acting locally, disrupts DNA synthesis and function in susceptible bacteria and protozoa.
Pharmacokinetics:
- Absorption: Minimal systemic absorption occurs with intravaginal administration. Approximately 1.3% of miconazole and 20% of an equivalent oral dose of ornidazole is absorbed.
- Metabolism: Ornidazole is metabolized in the liver, primarily by hepatic enzymes.
- Elimination: Primarily through renal excretion. The elimination half-life of ornidazole is prolonged in patients with liver cirrhosis, and the dosing interval should be doubled in patients with severe hepatic impairment.
Mode of Action:
- Miconazole: Binds to cytochrome P-450 enzymes in fungal cells, inhibiting the 14-alpha-demethylase enzyme necessary for converting lanosterol to ergosterol, a crucial component of the fungal cell membrane. This disruption results in cell membrane instability and leakage, leading to fungal cell death.
- Ornidazole: The nitro group of ornidazole is reduced intracellularly by susceptible anaerobic bacteria and protozoa. This reduced form of ornidazole then interacts with DNA, causing strand breakage, inhibition of nucleic acid synthesis, and ultimately, cell death.
Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation:
- Miconazole: Enzyme inhibition (14-alpha-demethylase).
- Ornidazole: DNA interaction, inhibition of nucleic acid synthesis.
Dosage
Standard Dosage
Adults:
- Vaginal Cream (Miconazole 2% + Ornidazole 2%): One full applicator (approximately 5g) inserted intravaginally once daily at bedtime for 6 consecutive days.
- Vaginal Tablets (Miconazole 100mg + Ornidazole 500mg): One tablet inserted high into the vagina once daily at bedtime for 6 days.
- Suppositories: Various strengths exist (e.g., Miconazole 1200mg single dose). Follow product-specific instructions.
Children:
Not generally recommended for prepubertal girls. For adolescent girls, consult pediatric dosage guidelines based on age/weight.
Special Cases:
- Elderly Patients: No specific dosage adjustments are typically needed.
- Patients with Renal Impairment: Caution is advised. Systemic absorption is minimal, but consider potential interactions with other medications.
- Patients with Hepatic Dysfunction: Caution is advised due to the potential for impaired drug metabolism. Double the interval between doses in patients with severe hepatic impairment.
- Patients with Comorbid Conditions: Evaluate individual cases, considering concomitant medications and potential drug interactions.
Clinical Use Cases
The combination of Miconazole and Ornidazole is specifically indicated for vaginal infections, and its dosage recommendations are tailored to that context. It is not typically employed in the clinical settings you described (Intubation, Surgical Procedures, Mechanical Ventilation, ICU Use, Emergency Situations). These clinical situations may warrant systemic antibiotics or antifungals for prophylactic or therapeutic purposes, but this specific combination product is not designed for systemic use.
Dosage Adjustments
Dosage adjustments may be necessary for patients with hepatic dysfunction (as noted above), and caution is advised in patients with renal impairment and comorbid conditions.
Side Effects
Common Side Effects:
- Local irritation (burning, itching, redness)
- Vaginal discharge
- Headache
- Nausea
- Vomiting
- Change or loss of taste
- Diarrhea
Rare but Serious Side Effects:
- Allergic reactions (rash, hives, itching, swelling, difficulty breathing)
- Peripheral neuropathy (numbness, tingling, pain in hands and feet)
- Seizures
- Leucopenia
Long-Term Effects:
Chronic complications from prolonged use of Miconazole + Ornidazole are rare, given its topical/local route of administration. However, prolonged or repeated use might increase the risk of developing resistant strains of Candida.
Adverse Drug Reactions (ADR):
Clinically significant ADRs include allergic reactions, peripheral neuropathy, and seizures. These warrant immediate medical attention.
Contraindications
- Hypersensitivity to miconazole, ornidazole, or any component of the formulation
- First trimester of pregnancy (Ornidazole)
- Porphyria (Miconazole)
- Milk protein allergy (some formulations)
- Patients with neurological disease (caution advised)
- Chronic alcoholics (caution advised)
Drug Interactions
- Warfarin: Miconazole can inhibit warfarin metabolism, potentially increasing the risk of bleeding. Close monitoring of INR is advised.
- Disulfiram: Ornidazole can potentiate the disulfiram-like reaction of alcohol.
- Alcohol: Avoid alcohol during and for at least 3 days after ornidazole treatment.
- Oral Hypoglycemics: Ornidazole can enhance the effects of some oral hypoglycemics.
- Phenytoin: Miconazole may increase phenytoin plasma concentrations.
- Latex Contraceptives: Miconazole may reduce the effectiveness of latex condoms and diaphragms.
Pregnancy and Breastfeeding
- Pregnancy: Avoid in the first trimester. Use with caution in the second and third trimesters only if the potential benefit justifies the potential risk to the fetus. Vaginal application is preferred over oral routes when ornidazole is used in pregnancy due to lower systemic absorption.
- Breastfeeding: Limited information is available. Caution is advised. Consider temporarily interrupting breastfeeding or using alternative treatments.
Drug Profile Summary
- Mechanism of Action: Miconazole inhibits fungal ergosterol synthesis; Ornidazole damages microbial DNA.
- Side Effects: Local irritation, nausea, vomiting, headache. Rarely, allergic reactions, peripheral neuropathy.
- Contraindications: Hypersensitivity, first trimester of pregnancy, porphyria.
- Drug Interactions: Warfarin, disulfiram, alcohol, phenytoin.
- Pregnancy & Breastfeeding: Avoid in the first trimester; caution in breastfeeding.
- Dosage: Vaginal cream/tablet once daily for 6 days; suppositories vary.
- Monitoring Parameters: For systemic use of ornidazole: Complete blood count, liver function tests. For topical use, monitor for local reactions and clinical response.
Popular Combinations
Miconazole is sometimes combined with other antifungals (e.g., clotrimazole) or corticosteroids (e.g., betamethasone) for broader coverage or to address inflammation. Ornidazole is combined with other antibiotics for mixed bacterial infections. However, the Miconazole + Ornidazole combination specifically targets the polymicrobial nature of many vaginal infections.
Precautions
- General Precautions: Screen for allergies and relevant medical history (liver/kidney disease).
- Pregnant Women: Avoid in the first trimester. Use with caution in later trimesters only if benefits outweigh risks.
- Breastfeeding Mothers: Limited information; caution advised.
- Children & Elderly: Not recommended for prepubertal girls. No specific dosage adjustments for elderly patients.
- Menstruating Individuals: Treatment can generally be completed before the onset of menstruation. If symptoms are pronounced, treatment may be continued during menstruation.
- Lifestyle Considerations: Avoid alcohol during and after ornidazole treatment. Latex contraceptives’ effectiveness may be reduced.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Miconazole + Ornidazole?
A: Adults: Vaginal cream/tablet once daily for 6 days. Suppositories as per product instructions. Not recommended for prepubertal girls.
Q2: Can Miconazole + Ornidazole be used during pregnancy?
A: Avoid in the first trimester. Use with caution in the second and third trimesters only if clearly needed.
Q3: What are the common side effects?
A: Local irritation, itching, burning, headache, nausea, vomiting.
Q4: What are the contraindications?
A: Hypersensitivity, first trimester of pregnancy, porphyria, milk protein allergy (some formulations).
Q5: How does Miconazole + Ornidazole work?
A: Miconazole disrupts fungal cell membranes; Ornidazole damages bacterial and protozoal DNA.
Q6: What infections does it treat?
A: Vaginal candidiasis, vaginal trichomoniasis, and bacterial vaginosis.
Q7: Are there any drug interactions I should be aware of?
A: Yes. It can interact with warfarin, disulfiram, alcohol, and some oral hypoglycemics. Always review a patient’s medication list before prescribing.
Q8: Can this combination be used in children?
A: Not recommended for prepubertal girls. Consult pediatric guidelines for adolescents.
Q9: Should I advise patients on any lifestyle modifications during treatment?
A: Yes. Advise patients to avoid alcohol during and for at least 3 days after treatment with ornidazole, and that latex contraceptives may be less reliable.
Q10: What should I do if a patient experiences an allergic reaction?
A: Discontinue treatment immediately and provide appropriate medical care.
