Antibiotics - Metronidazole: Nursing Pharmacology

Drug Overview

• Drug Name: Metronidazole (Flagyl)
• Classification: Antibiotic

Mechanism of Action

• Metronidazole produces free radicals inside anaerobic bacteria and protozoans, causing DNA damage and cell death.

Indications

• Treats infections like amebiasis, trichomoniasis, giardiasis
• Effective for bacterial vaginosis, septicemia, endocarditis
• Used for rosacea, bone, joint, and lower respiratory tract infections

Routes of Administration

• Oral (PO): Trichomoniasis, amebiasis, giardiasis
• Intravenous (IV): Anaerobic bacterial infections
• Topical (TOP): Bacterial vaginosis, rosacea

Side Effects

• CNS: headache, dizziness, confusion, irritability, insomnia, peripheral neuropathy, seizures, aseptic meningitis (IV)
• Cardiovascular (CV): ECG changes
• EENT: blurred vision, dry mouth, metallic taste
• Gastrointestinal (GI): anorexia, abdominal cramps, nausea, vomiting, diarrhea, CDI
• Hematologic (HEMA): bone marrow suppression, leukopenia, thrombocytopenia
• Genitourinary (GU): reddish urine, dysuria
• Integumentary (INTEG): skin rash, urticaria, phlebitis, Stevens-Johnson syndrome, toxic epidermal necrolysis
• Other: Disulfiram-like reaction with alcohol, Boxed warning on carcinogenic potential

Contraindications and Cautions

• Avoid during the first trimester of pregnancy and during breastfeeding
• Caution in elderly, those with heart failure, fungal infections, bone marrow suppression
• Risk for clients with CNS, hematologic, gastrointestinal, renal, or hepatic disease
• Drug interactions: zalcitabine, disulfiram, cimetidine, warfarin, phenytoin, lithium
• Avoid alcohol due to potential disulfiram-like reactions

Nursing Considerations

Assessment and Monitoring

• Assess genitourinary symptoms, laboratory test results including CBC, renal and hepatic function
• Monitor side effects and therapeutic effect (resolution of infection)

Client Education

• Purpose: Resolve infection
• Administration: Take full course, oral twice daily with food, avoid alcohol
• Intravaginally: Self-administration at bedtime, avoid vaginal intercourse, tampons, douches during treatment
• Lifestyle: Prevent recurrence by minimizing vaginal irritation, limiting sexual partners, and using condoms
• Managing Side Effects: Frequent sips of water, good oral hygiene, use of hard sugar-free candies
• Report Symptoms: CDI (abdominal pain, severe diarrhea, fever), numbness, tingling, rash, easy bruising